JP2013076668A - Internal resistance detection circuit and battery power supply apparatus - Google Patents

Abstract

An internal resistance detection circuit and a battery power supply device capable of improving the detection accuracy of an internal resistance value of a secondary battery are provided.
An internal resistance detection circuit includes: an individual resistance calculation unit that calculates a resistance value of a secondary battery B based on a current and a voltage of the secondary battery B; a charge state and temperature of the secondary battery B; The storage unit 107 stores the internal resistance value in association with each other, the internal resistance value stored in the storage unit 107 corresponding to the charging state and temperature of the secondary battery B, and the individual resistance calculation unit 103 The multiplication factor 112 that calculates the ratio of the measured resistance value as a magnification, and the internal resistance value stored in the storage unit 107 in association with the SOC and temperature of the secondary battery B are multiplied by the magnification. The internal resistance value acquisition unit 113 that acquires the multiplication value obtained as a result as the internal resistance value of the secondary battery B is provided.
[Selection] Figure 1

Description

  The present invention relates to an internal resistance detection circuit for detecting an internal resistance value of a secondary battery, and a battery power supply apparatus using the internal resistance detection circuit.

  2. Description of the Related Art Conventionally, in battery power supply devices that use a secondary battery to supply power to a load circuit, there is a wide range of battery blocks in which a plurality of secondary batteries are connected in parallel because the amount of output current required by the load circuit is required. It is used.

  Also, a technique for measuring the internal resistance of a secondary battery in order to determine the degree of deterioration of the secondary battery is known (see, for example, Patent Document 1). The technique described in Patent Document 1 includes a current sensor connected in series with a secondary battery, and a voltage sensor that measures the terminal voltage of the secondary battery. The current value detected by the current sensor and the voltage sensor The internal resistance of the secondary battery is calculated from the detected voltage value.

JP 2004-31170 A

  However, since the internal resistance value of the secondary battery changes under the influence of temperature, when the internal resistance value is obtained from the current value and the voltage value detected from the secondary battery, the internal resistance value is affected by the temperature. There was a disadvantage that the detection accuracy was lowered. The inventors of the present invention have also found that the internal resistance value of the secondary battery changes depending on the state of charge (SOC) of the secondary battery.

  The objective of this invention is providing the internal resistance detection circuit which can improve the detection accuracy of the internal resistance value of a secondary battery, and a battery power supply device using the same.

  An internal resistance detection circuit according to the present invention includes a current detection unit that detects a current flowing through a secondary battery, a voltage detection unit that detects a voltage of the secondary battery, and a temperature detection unit that detects a temperature of the secondary battery. A resistance value of the secondary battery based on a charge state detection unit that detects a charge state of the secondary battery, a current detected by the current detection unit, and a voltage detected by the voltage detection unit. The resistance value is calculated by the individual resistance calculation unit to be calculated, the storage unit that stores the charge state and temperature of the secondary battery, and the internal resistance value of the secondary battery in association with each other, and the individual resistance calculation unit. The magnification calculation for calculating the ratio between the internal resistance value stored in the storage unit corresponding to the charged state and temperature of the secondary battery and the resistance value calculated by the individual resistance calculation unit as a magnification And the resistance calculator The multiplication factor is added to the internal resistance value stored in the storage unit in association with the charge state detected by the charge state detection unit after the resistance value is calculated and the temperature detected by the temperature detection unit. An internal resistance value acquisition unit that acquires a multiplication value obtained by multiplying as an internal resistance value of the secondary battery.

  According to this configuration, the internal resistance value of the secondary battery is obtained based on the resistance value calculated from the current flowing through the secondary battery and the voltage of the secondary battery, and the charge state and temperature of the secondary battery. Therefore, the internal resistance value is obtained by reflecting the influence of the charging state and temperature of the secondary battery. As a result, the detection accuracy of the internal resistance value of the secondary battery can be improved.

  In addition, the storage unit includes information for discharging that associates a charging state and temperature in a state in which the secondary battery is discharged with an internal resistance value of the secondary battery, and in a state in which the secondary battery is being charged. Charging information that associates a charging state and temperature with an internal resistance value of the secondary battery is stored in advance, and the magnification calculation unit is detected by the current detection unit during a period when the secondary battery is discharged. When the resistance value is calculated by the individual resistance calculation unit based on the current and the voltage detected by the voltage detection unit, the magnification calculation unit calculates the magnification as a discharge magnification, and the secondary battery When the resistance value is calculated by the individual resistance calculation unit based on the current detected by the current detection unit and the voltage detected by the voltage detection unit during the charging period, The unit calculates the magnification as a charging magnification, and the internal resistance value acquisition unit stores the internal resistance value of the secondary battery in a period during which the secondary battery is discharged, and is stored in the storage unit. A multiplication value obtained by multiplying the internal resistance value associated with the state of charge and the temperature by the information for discharging being multiplied by the magnification is obtained as the internal resistance value of the secondary battery. When acquiring the internal resistance value of the secondary battery during the period when the secondary battery is charged, the charge state stored in the storage unit is associated with the charge state and the temperature. It is preferable to obtain a multiplication value obtained by multiplying the existing internal resistance value by the magnification as the internal resistance value of the secondary battery.

  According to this configuration, in addition to the influence of the charging state and temperature of the secondary battery, the internal resistance value is obtained by reflecting the change in the internal resistance value that occurs depending on whether the secondary battery is being discharged or being charged. Will be. As a result, the detection accuracy of the internal resistance value of the secondary battery can be further improved.

  In addition, a plurality of the secondary batteries are connected in parallel to constitute a battery module, the current detection unit detects an overall current that is a current flowing through the battery module, and the voltage detection unit Detecting an overall voltage which is a voltage between both ends, and the internal resistance detection circuit calculates a resistance value of the battery module based on the overall current and the overall voltage; and at least the plurality of the plurality of voltages One or more switching elements connected in series with respect to a number of secondary batteries that are one less than the number of secondary batteries included in the battery module among the secondary batteries, and the secondary battery and the switching element Are connected in series, or connected in parallel between each series circuit configured in series, or between a secondary battery to which the switching element is not connected and each series circuit. A plurality of secondary batteries and a connection part constituting the battery module including the one or more switching elements, wherein the individual resistance calculation unit turns on or off the switching elements in a predetermined manner. It is preferable to calculate at least one internal resistance value among the plurality of secondary batteries based on the resistance value calculated by the resistance calculation unit in the set state in which the above state is set.

  According to this configuration, the resistance value of the battery module is calculated by the resistance calculation unit based on the total current detected by the current detection unit and the total voltage detected by the voltage detection unit. In addition, the individual resistance calculator sets the switching element on and off in a predetermined state. If it does so, the internal resistance value of the secondary battery selected according to ON / OFF of a switching element will be reflected in the resistance value of a battery module. Therefore, the individual resistance calculation unit calculates at least one internal resistance value among the plurality of secondary batteries based on the resistance value calculated by the resistance calculation unit in a state where the switching element is turned on and off in a predetermined state. Can be calculated. In this case, since the number of current detection units required to detect the internal resistance value of the secondary battery may be one, the number of current detection units may be smaller than the number of secondary batteries connected in parallel. it can.

  The individual resistance calculation unit sequentially calculates internal resistance values of the plurality of secondary batteries while changing the on / off states of the switching elements in the setting state, and is calculated by the individual resistance calculation unit. It is preferable to further include an individual current calculation unit that calculates a current flowing through each of the secondary batteries based on the plurality of internal resistance values and the overall current.

  According to this configuration, the individual resistance calculation unit sequentially calculates the internal resistance values of the plurality of secondary batteries by changing the on / off states of the switching elements. The entire current flowing through the battery module is shunted according to the internal resistance value of each secondary battery. Therefore, the individual current calculation unit can calculate the current flowing through each secondary battery based on the internal resistance value of each secondary battery and the overall current detected by the current detection unit. As a result, each current value flowing through the plurality of secondary batteries can be detected only by providing one current detection unit.

  Moreover, the said individual electric current calculation part sets the number of the secondary battery contained in the said battery module to n, gives the number of 1-n to each said secondary battery, m number (m is any one among 1-n) The internal resistance value calculated by the individual resistance calculation unit is r (m), the total current is I, and the mth secondary battery using the following formula (A): It is preferable to calculate the current value I (m) of the current flowing through the.

  According to this configuration, the current flowing through each secondary battery can be calculated based on the internal resistance value of each secondary battery and the overall current detected by the current detection unit.

  The individual resistance calculation unit sequentially calculates the internal resistance values of the plurality of secondary batteries while changing the on / off states of the switching elements in the setting state, and the plurality of secondary batteries are all in parallel. The resistance value of the battery module in a connected state is calculated as an overall resistance value, and based on the ratio between each internal resistance value and the overall resistance value calculated by the individual resistance calculation unit, and the overall current In addition, it is preferable to further include an individual current calculation unit that calculates a current value of a current flowing through each of the secondary batteries.

  According to this configuration, the individual resistance calculation unit sequentially calculates the internal resistance values of the plurality of secondary batteries by changing the on / off states of the switching elements. The total current flowing through the battery module is distributed to each secondary battery according to the ratio between the internal resistance value of each secondary battery and the overall resistance value of the battery module that is a parallel circuit of a plurality of secondary batteries. Therefore, the individual current calculation unit can calculate the current value of the current flowing through each secondary battery based on the ratio between each internal resistance value and the total resistance value and the total current. As a result, each current value flowing through the plurality of secondary batteries can be detected only by providing one current detection unit.

In addition, the individual current calculation unit sets the number of secondary batteries included in the battery module to n, assigns numbers 1 to n to the secondary batteries, and calculates the individual resistance for the m-th secondary battery. The internal resistance value calculated by the unit is r (m), the total resistance value is R _total , the total current is I, and the current flowing through the m-th secondary battery is expressed by the following equation (B). It is preferable to calculate the current value I (m).

I (m) = {R _total / r (m)} × I (B)
According to this configuration, the individual current calculation unit flows to each secondary battery based on {R _total / r (m)} that is the ratio between each internal resistance value and the total resistance value and the total current I. The current value I (m) of the current can be calculated.

The individual resistance calculation unit sequentially calculates internal resistance values of the plurality of secondary batteries while changing the on / off state of the switching element in the set state, and the secondary battery included in the battery module N is assigned to each secondary battery, and the internal resistance value calculated by the individual resistance calculator for the m-th secondary battery is r (m). The ratio of r (1) to r (n) is p (1): p (2):...: p (n), and the upper limit value of the current that the mth secondary battery can flow is I. When it is _lim (m), it may further include an overall limit value calculation unit that calculates an overall limit value I _{lim_total} that is an allowable upper limit value of the overall current using the following equation (C).

According to this configuration, by using the formula (C), the internal resistance values r (1) to r (n) calculated by the individual resistance calculation unit and the upper limit of the current that can be flowed by one secondary battery. Based on the value, the total limit value calculation unit can calculate a total limit value I _{lim_total} that is an allowable upper limit value of the total current.

The individual resistance calculation unit sequentially calculates the internal resistance values of the plurality of secondary batteries while changing the on / off states of the switching elements in the setting state, and the plurality of secondary batteries are all in parallel. The resistance value of the battery module in a connected state is calculated as an overall resistance value, the number of secondary batteries included in the battery module is n, and each secondary battery is given a number from 1 to n, m For the secondary battery, the internal resistance value calculated by the individual resistance calculation unit is r (m), the total resistance value is R _total , and the ratio between R _total and r (m) is P _total : P ( m), and when the upper limit value of the current that can be passed through the mth secondary battery is I _lim (m), an overall limit value I _{lim_total} that is an allowable upper limit value of the overall current is _expressed as _follows : It is preferable to further include an overall limit value calculation unit that calculates using the equation (D).

According to this configuration, by using the equation (D), the internal resistance values r (1) to r (n) calculated by the individual resistance calculation unit and the overall resistance value R _total and the secondary battery flow. Based on the upper limit value of the current that can be _generated , the total limit value calculation unit can calculate the total limit value I _{lim_total} that is an allowable upper limit value of the total current.

  In addition, the individual resistance calculation unit includes an on / off state of a switching element connected to a target secondary battery that is a secondary battery to be detected from among the plurality of secondary batteries. , Based on the resistance value calculated by the resistance calculation unit in a setting state in which the on and off states of one or a plurality of switching elements connected to a secondary battery other than the target secondary battery are different from each other, It is preferable to calculate the internal resistance value of the target secondary battery.

  According to this configuration, the switching element connected to the target secondary battery is turned on and the switching element connected to another secondary battery is turned off, or the switching element connected to the target secondary battery is turned off. And the switching element connected to another secondary battery is turned on, or based on the resistance value of the battery module calculated by the resistance calculation unit in any setting state, the individual resistance calculation unit Calculate the internal resistance of the battery.

  Also, a plurality of the switching elements are provided, the plurality of switching elements are connected in series with all of the plurality of secondary batteries, and the connection unit connects all the series circuits in parallel, and the individual resistors The calculation unit causes the resistance calculation unit to calculate in a setting state in which a switching element connected to the target secondary battery is turned on and a switching element connected to a secondary battery other than the target secondary battery is turned off. It is preferable to obtain the obtained resistance value as the internal resistance value of the target secondary battery.

  According to this configuration, in the setting state in which the switching element connected to the target secondary battery is turned on and the switching element connected to a secondary battery other than the target secondary battery is turned off, the resistance value of the battery module Is equal to the internal resistance of the target secondary battery. Therefore, the individual resistance calculation unit is calculated by the resistance calculation unit in a setting state in which the switching element connected to the target secondary battery is turned on and the switching element connected to a secondary battery other than the target secondary battery is turned off. By acquiring the resistance value thus obtained as the internal resistance value of the target secondary battery, the internal resistance value of the target secondary battery can be obtained.

  In addition, the switching element is connected in series to the remaining secondary batteries except for one of the plurality of secondary batteries, and the connection portion includes all the series circuits and the one secondary battery. A basic secondary battery is connected in parallel, and the individual resistance calculation unit calculates the resistance value calculated by the resistance calculation unit in a setting state in which all the switching elements are turned off. Obtained as a value, calculated by the resistance calculation unit in a setting state in which a switching element connected to the target secondary battery is turned on and a switching element connected to a secondary battery other than the target secondary battery is turned off Obtaining the obtained resistance value as a partial resistance value, and calculating the internal resistance value of the target secondary battery based on the internal resistance value of the basic secondary battery and the partial resistance value Preferred.

  According to this configuration, the switching unit connected to the target secondary battery is turned on and the switching unit connected to a secondary battery other than the target secondary battery is turned off by the resistance calculation unit. The partial resistance value is a combined resistance value of the internal resistance value of the target secondary battery and the internal resistance value of the basic secondary battery. Therefore, the individual resistance calculation unit can calculate the internal resistance value of the target secondary battery based on the internal resistance value and the partial resistance value of the basic secondary battery. Furthermore, according to this structure, the number of switching elements can be made smaller than the number of secondary batteries.

  The individual resistance calculation unit calculates the internal resistance value r of the target secondary battery based on the following formula (E), where re is the internal resistance value of the basic secondary battery and Rb is the partial resistance value. It is preferable to do.

r = (re × Rb) / (re−Rb) (E)
By using the equation (E), the individual resistance calculation unit can calculate the internal resistance value r of the target secondary battery based on the internal resistance value re of the basic secondary battery and the partial resistance value Rb.

  Also, a plurality of the switching elements are provided, the plurality of switching elements are connected in series with all of the plurality of secondary batteries, and the connection unit connects all the series circuits in parallel, and the individual resistors The calculation unit obtains the resistance value calculated by the resistance calculation unit as a whole resistance value in a setting state in which all the switching elements are turned on, turns off the switching elements connected to the target secondary battery, and A resistance value calculated by the resistance calculation unit in a setting state in which a switching element connected to a secondary battery other than the target secondary battery is turned on is acquired as a partial resistance value, and the total resistance value and the partial resistance value Based on the above, it is preferable to calculate the internal resistance value of the target secondary battery.

  According to this configuration, the individual resistance calculation unit turns off only one switching element connected to the target secondary battery whose internal resistance is to be calculated, and turns on the other switching element to thereby turn on the target secondary battery. Thus, the number of secondary batteries separated from the battery module for calculating the internal resistance value can be minimized. As a result, it becomes easy to calculate the internal resistance value of the target secondary battery while using the battery module.

  In addition, the switching element is connected in series to the remaining secondary batteries except for one of the plurality of secondary batteries, and the connection portion includes all the series circuits and the one secondary battery. A certain basic secondary battery is connected in parallel, and the individual resistance calculation unit is calculated by the resistance calculation unit using the total current and the total voltage in a setting state in which all the switching elements are turned on. The resistance value is acquired as an overall resistance value, the switching element connected to the target secondary battery is turned off, and the switching element connected to a secondary battery other than the target secondary battery is turned on. The resistance value calculated by the resistance calculation unit using the total current and the total voltage is acquired as a partial resistance value, and based on the total resistance value and the partial resistance value, It is preferable to calculate the internal resistance value of the target secondary battery.

  According to this configuration, the switching element connected to the target secondary battery is turned off, and the switching element connected to a secondary battery other than the target secondary battery is turned on, and is calculated by the resistance calculation unit. The partial resistance value is a combined resistance value of secondary batteries other than the target secondary battery. On the other hand, since the total resistance value is the combined resistance value of all the secondary batteries, the difference between the total resistance value and the partial resistance value is caused by the internal resistance value of the target secondary battery. Therefore, the individual resistance calculation unit can calculate the internal resistance value of the target secondary battery based on the overall resistance value and the partial resistance value. Furthermore, according to this structure, the number of switching elements can be made smaller than the number of secondary batteries.

Further, the individual resistance calculation unit calculates internal resistance values r of all the remaining secondary batteries by sequentially setting the remaining secondary batteries as the target secondary batteries, and the all the remaining secondary batteries are calculated. Based on the internal resistance value r of the battery, a combined resistance value obtained by connecting all the remaining secondary batteries in parallel is calculated as Rc, and the total resistance value is _Rtotal. An internal resistance value re of the basic secondary battery is calculated.

re = (Rc × R _total ) / (Rc−R _total ) (F)
According to this configuration, by using the formula (F), the individual resistance calculation unit can calculate the basic secondary battery based on the combined resistance value Rc of the secondary batteries other than the basic secondary battery and the total resistance value R _total. The internal resistance value re can be calculated.

Moreover, it is preferable that the said individual resistance calculation part calculates the internal resistance value r of the said object secondary battery based on following formula (G), when the said total resistance value is set to _Rtotal and the said partial resistance value is set to Rb. .

r = (Rb × R _total ) / (Rb−R _total ) (G)
According to this configuration, by using the formula (G), the individual resistance calculation unit can calculate the internal resistance value r of the target secondary battery based on the overall resistance value _Rtotal and the partial resistance value Rb. it can.

  Also, a plurality of the switching elements are provided, the plurality of switching elements are connected in series with all of the plurality of secondary batteries, and the connection unit connects all the series circuits in parallel, and the individual resistors The calculation unit calculates the resistance value calculated by the resistance calculation unit in a setting state in which one of the plurality of switching elements is turned on, and the internal resistance of the secondary battery connected in series with the turned on switching element. After obtaining the value, the remaining switching elements other than the turned on switching elements are sequentially turned on, and each time the sequential turning on is performed, the resistance value calculated by the resistance calculating unit immediately before the sequential turning on. 1 partial resistance value and a second partial resistance value that is a resistance value calculated by the resistance calculation unit in the sequentially turned on state. Zui it may be calculated internal resistance value of the object secondary battery as secondary batteries connected sequentially turned-on switching element in series.

  According to this configuration, the second partial resistance value is a combined resistance value obtained by connecting the target secondary battery in parallel to the parallel circuit of the secondary batteries having the first partial resistance value. That is, the difference between the first partial resistance value and the second partial resistance value is caused by the internal resistance value of the target secondary battery. Based on the two-part resistance value, the internal resistance value of the target secondary battery can be calculated.

  In addition, the switching element is connected in series to the remaining secondary batteries except for one of the plurality of secondary batteries, and the connection portion includes all the series circuits and the one secondary battery. A basic secondary battery is connected in parallel, and the individual resistance calculation unit calculates the resistance value calculated by the resistance calculation unit in a setting state in which all the switching elements are turned off. After obtaining the value, the switching elements are sequentially turned on, and each time the switching elements are sequentially turned on, the first partial resistance value, which is a resistance value calculated by the resistance calculation unit immediately before the sequential turning on, and the sequential Based on the second partial resistance value, which is the resistance value calculated by the resistance calculation unit in the ON state, the switching elements that are sequentially turned ON are connected in series. May be calculated internal resistance value of the target secondary battery is a secondary battery.

  According to this configuration, in the setting state in which all the switching elements are turned off, the secondary battery connected to the battery module is only the basic secondary battery. The resistance value calculated by the resistance calculation unit in the turned-off setting state can be acquired as the internal resistance value of the basic secondary battery. Furthermore, the second partial resistance value is a combined resistance value obtained by connecting the target secondary battery in parallel to the parallel circuit of the secondary batteries having the first partial resistance value. That is, the difference between the first partial resistance value and the second partial resistance value is caused by the internal resistance value of the target secondary battery. Based on the two-part resistance value, the internal resistance value of the target secondary battery can be calculated.

  Also, a plurality of the switching elements are provided, the plurality of switching elements are connected in series with all of the plurality of secondary batteries, and the connection unit connects all the series circuits in parallel, and the individual resistors The calculation unit sets the setting state in which the plurality of switching elements are sequentially turned off one by one after the resistance value is calculated by the resistance calculation unit in the setting state in which the plurality of switching elements are turned on. The first partial resistance value that is the resistance value calculated by the resistance calculation unit in the sequentially turned off state, and the second partial resistance value that is the resistance value calculated by the resistance calculation unit immediately before the sequential turning off The internal resistance value of the target secondary battery, which is a secondary battery connected in series with the sequentially turned off switching elements, is calculated based on It may be.

  According to this configuration, the second partial resistance value is a combined resistance value obtained by connecting the target secondary battery in parallel to the parallel circuit of the secondary batteries having the first partial resistance value. That is, the difference between the first partial resistance value and the second partial resistance value is caused by the internal resistance value of the target secondary battery. Based on the two-part resistance value, the internal resistance value of the target secondary battery can be calculated.

  In addition, the switching element is connected in series to the remaining secondary batteries except for one of the plurality of secondary batteries, and the connection portion includes all the series circuits and the one secondary battery. A certain basic secondary battery is connected in parallel, and the individual resistance calculation unit calculates a resistance value by the resistance calculation unit in a setting state in which all the switching elements are turned on, and then the plurality of switching elements. A setting state in which the resistors are sequentially turned off one by one, and each time the devices are sequentially turned off, the first partial resistance value, which is a resistance value calculated by the resistance calculation unit in the sequentially turned off state, and the resistor just before the sequential turning off The target secondary battery, which is a secondary battery connected in series with the switching elements that are sequentially turned off based on the second partial resistance value that is the resistance value calculated by the calculation unit It may be calculated internal resistance value.

  According to this configuration, the second partial resistance value is a combined resistance value obtained by connecting the target secondary battery in parallel to the parallel circuit of the secondary batteries having the first partial resistance value. That is, the difference between the first partial resistance value and the second partial resistance value is caused by the internal resistance value of the target secondary battery. Based on the two-part resistance value, the internal resistance value of the target secondary battery can be calculated.

  The individual resistance calculator calculates the internal resistance value r of the target secondary battery based on the following formula (H) when the first partial resistance value is Rs and the second partial resistance value is Rp. It is preferable to do.

r = (Rs × Rp) / (Rs−Rp) (H)
According to this configuration, by using the equation (H), the individual resistance calculation unit can calculate the internal resistance value r of the target secondary battery based on the first partial resistance value Rs and the second partial resistance value Rp. it can.

  The resistance calculation unit obtains a plurality of sets of the total current and the total voltage detected at the synchronized timing by the current detection unit and the voltage detection unit, and a regression obtained from the plurality of sets. It is preferable to calculate the slope of the straight line as the resistance value of the battery module.

  According to this configuration, the resistance calculation unit can calculate the resistance value of the battery module in a state where the battery module is in a use state in which the battery module is charged and discharged.

  The battery controller further includes a discharge controller that controls current supply from the battery module to the load, and the resistance calculator synchronizes with the change in the current supply amount when the discharge control unit changes the current supply amount. The resistance value of the battery module may be calculated based on the amount of change in the overall voltage and the amount of change in the overall current.

  According to this configuration, the resistance value of the battery module can be calculated at a timing when the discharge control unit changes the current supply amount. Therefore, it is not necessary to change the discharge amount of the battery module only for the purpose of calculating the resistance value of the battery module.

  A switching unit configured to open and close a current supply path from the battery module to a load, wherein an upper limit value of a current that can be flowed by one secondary battery in the plurality of secondary batteries is set; And a current limiter that is connected in parallel and is capable of switching between a cut-off state that cuts off current and a limit state that limits current flowing in a range not exceeding the upper limit, and the current limiter in the set state A discharge control unit that starts current supply to the load by switching from a cut-off state to the limit state; and the resistance calculation unit is configured to supply the current supply when the discharge control unit starts the current supply. A resistance value of the battery module is calculated based on the change amount of the overall voltage and the change amount of the overall current generated in synchronization with the change of the amount, and the individual resistance is calculated. The calculation unit ends the setting state by turning on the plurality of switching elements after the resistance value is calculated by the resistance calculation unit in the setting state, and the discharge control unit includes the plurality of switching elements. Preferably, the current supply path is closed by the switching unit after the element is turned on.

  According to this configuration, when the discharge control unit starts to supply current from the battery module to the load, first, current supply from the battery module to the load is performed in a limited state where the current flowing by the current limiting unit is limited. If it does so, the electric current which flows from a battery module to load will be restrict | limited to the range which does not exceed the upper limit of the electric current which one secondary battery can flow. Then, the resistance calculation unit calculates the amount of change in the total voltage and the total current generated in synchronization with the change in the current supply amount due to the start of the current supply in a state where the switching element is turned on and off in a predetermined setting state. The resistance value of the battery module is calculated based on the amount of change. When calculating this resistance value, there may be a setting state in which there is one secondary battery connected to the battery module, but the current flowing through the battery module does not exceed the above upper limit value. Does not exceed the upper limit. As a result, the risk of degrading the secondary battery is reduced.

  A switching unit configured to open and close a current supply path from the battery module to a load, wherein an upper limit value of a current that can be flowed by one secondary battery in the plurality of secondary batteries is set; Connected in parallel with each other, and a cut-off state in which the current is cut off, and a limit state in which a current flowing in a range not exceeding the product of the number of secondary batteries included in the battery module and the upper limit value is limited. A current control unit that can be switched to the current control unit, and a discharge control unit that starts current supply to the load by switching the current control unit from the cut-off state to the limit state in the set state. When the discharge control unit starts the current supply, the calculation unit calculates the change amount of the total voltage and the total current generated in synchronization with the change of the current supply amount. Based on the amount of change, the resistance value of the battery module is calculated, and the individual resistance calculation unit turns on the plurality of switching elements after the resistance calculation unit calculates the resistance value in the set state. Then, the setting state may be terminated, and the discharge control unit may cause the switching unit to close the current supply path after the plurality of switching elements are turned on.

  According to this configuration, when the discharge control unit starts to supply current from the battery module to the load, first, current supply from the battery module to the load is performed in a limited state where the current flowing by the current limiting unit is limited. Then, the current flowing from the battery module to the load does not exceed the product of the upper limit value of the current that can be passed by one secondary battery and the number that is one less than the number of secondary batteries included in the battery module. Limited. Then, the resistance calculation unit calculates the amount of change in the total voltage and the total current generated in synchronization with the change in the current supply amount due to the start of the current supply in a state where the switching element is turned on and off in a predetermined setting state. The resistance value of the battery module is calculated based on the amount of change. When calculating this resistance value, there may be a setting state in which one secondary battery is disconnected from the battery module by the switching element. However, since the current flowing through the battery module does not exceed the above multiplication value, each secondary battery The possibility that the current flowing through the upper limit exceeds the upper limit is reduced. As a result, the risk of degrading the secondary battery is reduced.

  In addition, a charging upper limit value that is an upper limit value of a charging current of one secondary battery in the plurality of secondary batteries is preset, and further includes a charge control unit that controls a charging current for charging the battery module, The charging control unit changes the charging current in a range that does not exceed the charging upper limit value in the setting state, and the resistance calculation unit generates the whole generated in synchronization with the change of the charging current in the setting state Based on the amount of change in voltage and the amount of change in the overall current, the resistance value of the battery module is calculated, and the individual resistance calculation unit calculates the resistance value by the resistance calculation unit in the set state. Thereafter, the setting state is terminated by turning on the plurality of switching elements, and the charging control unit is configured to change the charging current after the plurality of switching elements are turned on. It may be increased beyond the serial limit.

  According to this configuration, the charging control unit changes the charging current of the battery module within a range not exceeding the charging upper limit value in a state where the switching elements are turned on and off in a predetermined setting state. Then, the resistance calculation unit calculates the resistance value of the battery module based on the change amount of the overall voltage and the change amount of the overall current generated in synchronization with the change of the charging current. When calculating this resistance value, there may be a setting state in which there is one secondary battery connected to the battery module, but since the current flowing through the battery module does not exceed the upper limit of charge, the secondary battery The current charged in the battery does not exceed the charge upper limit value. As a result, the risk of degrading the secondary battery is reduced.

  In addition, a charging upper limit value that is an upper limit value of a charging current of one secondary battery in the plurality of secondary batteries is preset, and further includes a charge control unit that controls a charging current for charging the battery module, The charge control unit, in the set state, changes the charge current in a range not exceeding a product of a number less than the number of secondary batteries included in the battery module and the charge upper limit value, and calculates the resistance The unit calculates a resistance value of the battery module based on a change amount of the overall voltage and a change amount of the overall current generated in synchronization with the change of the charging current in the set state, and calculates the individual resistance And after the calculation of the resistance value by the resistance calculation unit in the set state, the unit ends the set state by turning on the plurality of switching elements, and the charging Control unit may be adapted to increase the charging current after the plurality of switching elements is turned on.

  According to this configuration, the charge control unit is a product of the charge upper limit value multiplied by one less than the number of secondary batteries included in the battery module in a state where the switching elements are turned on and off in a predetermined setting state. The charging current of the battery module is changed within a range not exceeding. Then, the resistance calculation unit calculates the resistance value of the battery module based on the change amount of the overall voltage and the change amount of the overall current generated in synchronization with the change of the charging current. When calculating this resistance value, there is a case where one secondary battery is disconnected from the battery module by the switching element, but the charging current flowing through the battery module does not exceed the multiplication value. The current charged in the battery does not exceed the charge upper limit value. As a result, the risk of degrading the secondary battery is reduced.

  A battery power supply device according to the present invention includes the above-described internal resistance detection circuit and a secondary battery.

  According to this configuration, in the battery power supply device provided with the internal resistance detection circuit, the number of current detection units necessary for detecting the internal resistance value of the secondary battery is determined from the number of secondary batteries connected in parallel. Can be less

  The internal resistance detection circuit having such a configuration and the battery power supply device using the same can improve the detection accuracy of the internal resistance value of the secondary battery.

1 is a block diagram illustrating an example of a battery power supply system including an internal resistance detection circuit according to a first embodiment of the present invention and a battery power supply device including the internal resistance detection circuit. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is explanatory drawing which shows an example of the change of the whole current I and the whole voltage V before and after the timing Ton when the switching element 43 was turned on. It is explanatory drawing for demonstrating the change of the whole electric current I at the time of repeating the output of a charge pulse 3 times, and the whole voltage V. FIG. It is explanatory drawing for demonstrating an example of the calculation method of internal resistance value r (m) by a resistance calculation part. 4 is a flowchart showing a modification of the operation shown in FIG. 3. 4 is a flowchart showing a modification of the operation shown in FIG. 3. It is a flowchart which shows the modification of the operation | movement shown in FIG. It is a flowchart which shows the modification of the operation | movement shown in FIG. It is a flowchart which shows the modification of the operation | movement shown in FIG. It is a flowchart which shows the modification of the operation | movement shown in FIG. It is a block diagram which shows an example of a structure of the battery power supply system which concerns on 2nd Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. (A) shows an example of a lookup table for discharge, (b) is an explanatory diagram showing an example of a lookup table for charging.

  Embodiments according to the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing an example of a battery power supply system including an internal resistance detection circuit according to a first embodiment of the present invention and a battery power supply device including the same.

  A battery power supply system 3 shown in FIG. 1 is configured by combining a battery power supply device 1 and an external device 2. 1 includes a battery module 5, a current detection unit 6, a voltage detection unit 7, Z1 to Zn, temperature sensors X1 to Xn (an example of a temperature detection unit), a control unit 10, a switching unit 41, a current. A limiting unit 42, a communication unit 11, and connection terminals 15, 16, and 17 are provided.

  The battery module 5 includes n secondary batteries B1 to Bn, n switching elements SW1 to SWn, and wirings 52 and 53 (an example of a connecting portion). The secondary batteries B1 to Bn and the switching elements SW1 to SWn are assigned numbers 1 to n, respectively. Hereinafter, the secondary batteries B1 to Bn are collectively referred to as a secondary battery B, and the switching elements SW1 to SWn are collectively referred to as a switching element SW.

  One end of the switching elements SW1 to SWn is connected to one end (for example, positive electrode) of the secondary batteries B1 to Bn. The other ends of the switching elements SW1 to SWn are connected to each other by a wiring 52. The other ends (for example, negative electrodes) of the secondary batteries B <b> 1 to Bn are connected to each other by a wiring 53. As a result, a plurality of series circuits constituted by the secondary battery B and the switching element SW are connected in parallel by the wirings 52 and 53 to constitute the battery module 5.

  And the part remove | excluding secondary battery B1-Bn from the battery power supply device 1 is an example of the internal resistance detection circuit 4. FIG.

  In addition, although the battery power supply device 1 showed the example provided with the battery module 5 in which several secondary battery B1-Bn was connected in parallel, the battery power supply device 1 is provided with only one secondary battery B, and is a switching element. A configuration without SW may be used.

  The wiring 52 is connected to the connection terminal 15 via the current detection unit 6 and the switching unit 41. The wiring 53 is connected to the connection terminal 16.

  As switching element SW, various switching elements, such as semiconductor switching elements, such as FET (Field Effect Transistor), and a relay switch, can be used, for example.

  The secondary battery B is configured as an assembled battery in which a plurality of single cells (cells) 51 are connected in series, for example. The secondary battery B is not limited to a plurality of single batteries connected in series, and one single battery may be used as the secondary battery B as it is. Further, the secondary battery B may be one in which a plurality of single cells are connected in parallel. Alternatively, the secondary battery B may be an assembled battery configured by combining a plurality of single cells by a connection method in which series connection and parallel connection are combined.

  As the single battery 51, various secondary batteries, such as nonaqueous electrolyte secondary batteries, such as a lithium ion secondary battery, and aqueous solution type secondary batteries, such as a nickel-hydrogen secondary battery, can be used.

The upper limit value of the current that can be discharged by the secondary batteries B <b> 1 to Bn is preset and stored in the storage unit 107, for example. Hereinafter, the upper limit value of the current that can be discharged by the secondary battery having the number m (m is any one of 1 to n) is referred to as a current upper limit value I _lim (m). The current upper limit values I _lim (1) to I _lim (n) may be the same value, and in this case, the current upper limit values of the secondary batteries B1 to Bn may be I _lim. Good.

Further, the upper limit value of the charging current that can charge one secondary battery B is preset as the charging upper limit value Ic _lim and stored in the storage unit 107, for example.

  The current detection unit 6 is configured using, for example, a shunt resistor, an analog digital converter, or the like. The current detection unit 6 detects the current flowing through the battery module 5 as the entire current I. Specifically, the current detection unit 6 outputs, for example, a signal representing the charging current of the battery module 5 as a positive current value and a discharging current as a negative current value to the control unit 10 as a signal representing the total current I. .

  The voltage detection unit 7 is configured using, for example, an analog-digital converter. The voltage detection unit 7 detects the voltage between the wiring 52 and the wiring 53, that is, the total voltage V that is the voltage between both ends of the battery module 5, and outputs a signal representing the total voltage V to the control unit 10. .

  The voltage detection units Z1 to Zn are configured using, for example, an analog-digital converter. And the voltage detection parts Z1-Zn are respectively connected in parallel with the secondary batteries B1-Bn, and detect the terminal voltages V (1) -V (n) of the secondary batteries B1-Bn. For example, when the switching element SWm is turned off, the terminal voltage V (m) detected by the voltage detection unit Zm represents an open circuit voltage (OCV) of the secondary battery Bm. Hereinafter, the voltage detection units Z1 to Zn are collectively referred to as a voltage detection unit Z.

  Note that the voltage detector 7 is not necessarily provided. For example, the terminal voltage detected by any one of the voltage detection units Z connected to the switching element SW that is turned on without using the voltage detection unit 7 may be used as the overall voltage V. .

  Moreover, the voltage detection part Z is not necessarily restricted to detecting the whole voltage V collectively. For example, the voltage detection unit Z is configured by a plurality of voltage detection units that respectively detect the terminal voltages of the unit cells 51 connected in series, and the terminal voltages V (1) to V (V) are obtained by adding the terminal voltages of the unit cells 51. (N) may be detected. Alternatively, the secondary battery B is divided into a plurality of series circuits in which several single cells 51 are connected in series, and the voltage detection unit Z is configured by a plurality of voltage detection units that respectively detect the terminal voltages of each series circuit. Then, the terminal voltages V (1) to V (n) may be detected by summing the terminal voltages of the series circuits.

  Hereinafter, it is assumed that the current detection unit 6 and the voltage detection units 7 and Z constantly update the total current I, the total voltage V, and the terminal voltages V (1) to V (n) to the latest values. That is, in the following description, the overall current I, the overall voltage V, and the terminal voltages V (1) to V (n) indicate the latest values updated in real time.

  The temperature sensors X1 to Xn are configured using a thermal element such as a thermistor or a thermocouple, for example. The temperature sensors X1 to Xn are disposed in close contact with, for example, the secondary batteries B1 to Bn or in the vicinity of the secondary batteries B1 to Bn, respectively. The temperature sensors X1 to Xn detect the temperatures T1 to Tn of the secondary batteries B1 to Bn and output signals indicating the temperatures T1 to Tn to the control unit 10. Note that it is not always necessary to provide a plurality of temperature sensors. For example, one temperature sensor that detects the temperature T of the entire battery module 5 may be provided. Hereinafter, the temperature sensors X1 to Xn are collectively referred to as a temperature sensor X.

  As the switching unit 41, various switching elements such as a semiconductor switching element such as an FET and a relay switch can be used.

The current limiting unit 42 is connected in parallel with the switching unit 41. For example, the current limiting unit 42 is configured by connecting a switching element 43 and a resistor 44 in series. The resistor 44 _{reduces the} inrush current that flows from the battery module 5 to the external device 2 when the switching element 43 is turned on, below the current upper limit value I _{lim_min} that is the minimum value of I _lim (1) to I _lim (n). The resistance value is limited to The state in which the switching element 43 is turned off corresponds to the cutoff state of the current limiting unit 42, and the state in which the switching element 43 is turned on corresponds to the limited state of the current limiting unit 42.

  The control unit 10 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a ROM (Read Only Memory) that stores a predetermined control program, and a RAM (Random Access Memory) that temporarily stores data. For example, the storage unit 107 is configured by an EEPROM (Electrically Erasable and Programmable Read Only Memory) and its peripheral circuits. Then, the control unit 10 executes, for example, a control program stored in the ROM, thereby causing the discharge control unit 101, the charge control unit 102, the SOC detection unit 111, the individual resistance calculation unit 103, the resistance calculation unit 104, and the magnification calculation unit. 112, functions as an internal resistance value acquisition unit 113, an individual current calculation unit 105, and an overall limit value calculation unit 106.

The storage unit 107 includes an SOC calculation lookup table that associates the open circuit voltage of the secondary battery B with the SOC in addition to the above-described current upper limit values I _lim (1) to I _lim (n) and the charging upper limit value Ic _lim. The discharge lookup table LUT1 shown in FIG. 25A and the charge lookup table LUT2 shown in FIG. 25B are stored in advance. The discharge lookup table LUT1 corresponds to an example of discharge information, and the charge lookup table LUT2 corresponds to an example of charge information.

  The discharge lookup table LUT1 is information that associates the charge state and temperature T in a state where the secondary battery B is discharged with the internal resistance value rt of the secondary battery B. The charge lookup table LUT2 is information that associates the charge state and temperature T in a state where the secondary battery B is discharged with the internal resistance value rt of the secondary battery B.

  Hereinafter, the state of charge of the secondary battery is referred to as SOC (State Of Charge). The SOC represents the ratio of the amount of charged electricity charged in the secondary battery to the full charge capacity of the secondary battery, for example, expressed in% (percentage).

  The discharge look-up table LUT1 is experimental, for example, by measuring the internal resistance value when the temperature T and the SOC are changed while discharging a new (initial state) secondary battery B that has not deteriorated. Can get to. The charge lookup table LUT2 is experimental, for example, by measuring the internal resistance value when the temperature T and the SOC are changed while charging a new (initial state) secondary battery B that has not deteriorated. Can get to.

  Note that the storage unit 107 does not necessarily need to store the discharge lookup table LUT1 and the charge lookup table LUT2. The storage unit 107 may store only one lookup table LUT that is shared between discharging and charging.

  The external device 2 illustrated in FIG. 1 includes, for example, a charge / discharge control unit 21, a power generation device 22, a load device 23, a communication unit 24, and connection terminals 25, 26, and 27. The connection terminals 25 and 26 are connected to the charge / discharge control unit 21, and the connection terminal 27 is connected to the charge / discharge control unit 21 via the communication unit 24. The power generation device 22 and the load device 23 are connected to the charge / discharge control unit 21. The external device 2 is a load of the battery power supply device 1.

  When the battery power supply device 1 and the external device 2 are combined, the connection terminals 15, 16, 17 and the connection terminals 25, 26, 27 are connected to each other.

  The communication units 11 and 24 are communication interface circuits. When the connection terminals 17 and 27 are connected, data transmission / reception can be performed between the communication units 11 and 24. The control unit 10 and the charge / discharge control unit 21 can transmit and receive data to and from each other via the communication units 11 and 24.

  The power generation device 22 is, for example, a solar power generation device (solar cell), a generator driven by natural energy such as wind power or hydraulic power, or artificial power such as an engine. In addition, the charge / discharge control part 21 may be connected to the commercial power supply instead of the electric power generating apparatus 22, for example.

  The load device 23 is various loads driven by power supplied from the battery power supply device 1, and may be, for example, a motor or a load device to be backed up.

  The charge / discharge control unit 21 charges the battery module 5 with surplus power from the power generation device 22 and regenerative power generated by the load device 23. Further, the charge / discharge control unit 21 causes the current consumption of the load device 23 to increase rapidly, or the power generation amount of the power generation device 22 to decrease and the power required by the load device 23 to exceed the output of the power generation device 22. Insufficient power is supplied from the battery module 5 to the load device 23.

  In addition, when a charge current instruction signal is transmitted from the charge control unit 102 via the communication units 11 and 24, the charge / discharge control unit 21 sends the charge current corresponding to the instruction signal to the connection terminals 25, 26 to the battery module 5. In addition, the charging / discharging control unit 21 communicates a startup instruction signal of the battery power supply device 1 when a startup instruction of the battery power supply system 3 by the user is received by a startup reception unit such as a startup switch or an ignition key (not shown), for example. The information is transmitted to the individual resistance calculation unit 103 via the units 24 and 11.

In addition, when the total limit value I _{limit_total} is transmitted from the total limit value calculation unit 106, the charge / discharge control unit 21 limits the current value when charging the battery module 5 to the total limit value I _{limit_total} or less.

  When the battery power supply device 1 is stopped (standby), the discharge control unit 101 shuts off the charging / discharging path of the battery module 5 by turning off the switching unit 41 and the switching element 43. In addition, the discharge control unit 101 turns on the switching element 43 after the individual resistance calculation unit 103 turns on and off the switching elements SW1 to SWn according to the activation instruction signal from the charge / discharge control unit 21. As a result, current supply from the battery module 5 to the external device 2 is started. Here, the setting state is a state in which only one of the switching elements SW1 to SWn is turned on, for example.

The external device 2 is often a capacitive load as viewed from the battery power supply device 1. When the external device 2 has a capacitive load, an inrush current for charging the capacity of the external device 2 flows immediately after the current supply from the battery module 5 to the external device 2 is started. However, since the inrush current is limited to a value smaller than the current upper limit value I _{lim_min} by the resistor 44, a current _exceeding the current upper limit values I _lim (1) to I _lim (n) is applied to the secondary batteries B1 to Bn. It is prevented from flowing.

  Further, the discharge control unit 101 turns on the switching unit 41 after the individual resistance calculation unit 103 turns on the switching elements SW1 to SWn and releases the set state.

When it becomes necessary to charge the battery module 5, the charging control unit 102 outputs an instruction signal for requesting supply of a charging current to the charging / discharging control unit 21. For example, when the overall voltage V detected by the voltage detection unit 7 is lower than a discharge end voltage V _end set in advance as a low voltage that should prohibit discharge of the battery module 5, the charge control unit 102 And charging / discharging control unit 21 is requested to supply charging current.

  The SOC detection unit 111 detects SOC1 to SOCn, which are the SOCs of the secondary batteries B1 to Bn. For example, the SOC detection unit 111 acquires the terminal voltage V (m) detected by the voltage detection unit Zm as the open circuit voltage of the secondary battery Bm when the switching element SWm is turned off by the individual resistance calculation unit 103. And the SOC detection part 111 detects SOC1-SOCn sequentially by acquiring SOC matched with the open circuit voltage obtained in this way as SOCm by the lookup table for SOC calculation. Can do.

  Note that the SOC detection unit 111 integrates current values I (1) to I (n) flowing through the secondary batteries B1 to Bn, respectively, and obtains the ratio of the integrated value to the full charge capacity of the secondary battery B. SOC1 to SOCn may be calculated, and SOC1 to SOCn can be obtained by various other methods. It is assumed that SOC detection unit 111 constantly updates SOC1 to SOCn to the latest values. That is, in the following description, SOC1 to SOCn indicate the latest values updated by the SOC detection unit 111.

  In the setting state in which the switching elements SW1 to SWn are turned on and off in a predetermined state (combination), the individual resistance calculation unit 103 sets the internal resistance value of the secondary battery corresponding to the setting state by the resistance calculation unit 104. Let it be calculated. Then, the individual resistance calculation unit 103 causes the resistance calculation unit 104 to sequentially calculate the internal resistance values of the secondary batteries corresponding to the changed setting state while sequentially changing the setting state. In this way, the individual resistance calculation unit 103 calculates the internal resistance values r (1) to r (n) of the secondary batteries B1 to Bn.

  Hereinafter, the setting state corresponding to the secondary battery B having the number m is referred to as a setting state m. For example, the setting state m is a state in which the switching element SWm is turned on and the switching elements SW other than the switching element SWm are turned off.

  For example, the setting state 1 is a state in which the switching element SW1 is turned on and the switching elements SW2 to SWn are turned off. The setting state n is a state in which the switching elements SW1 to SW (n-1) are turned off and the switching element SWn is turned on.

  Note that the individual resistance calculation unit 103 does not necessarily calculate all the internal resistance values r (1) to r (n) of the secondary batteries B1 to Bn, and any target secondary for calculating the internal resistance value. What is necessary is just to calculate the internal resistance value of a battery.

In addition, the individual resistance calculation unit 103 sets the resistance value of the battery module 5 in a setting state in which, for example, all the switching elements SW1 to SWn are turned on, that is, in a state where all the secondary batteries B1 to Bn are connected in parallel. To calculate. Then, the individual resistance calculation unit 103 acquires the resistance value thus obtained as an overall resistance value R _total .

The individual resistance calculation unit 103 may calculate an overall resistance value R _total that is a combined resistance based on, for example, the following equation (1) from the internal resistance values r (1) to r (n).

_Rtotal = 1 / {(1 / r (1)) + (1 / r (2)) +... + (1 / r (n))} (1)
Note that the individual resistance calculation unit 103 does not necessarily have to calculate the _total resistance value _Rtotal .

  The resistance calculation unit 104 is a battery module that has been set to a predetermined setting state by the individual resistance calculation unit 103 based on the total current I detected by the current detection unit 6 and the total voltage V detected by the voltage detection unit 7. The resistance value of 5 is calculated.

  Based on the internal resistance values r (1) to r (n) and the total current I detected by the current detection unit 6, the individual current calculation unit 105 determines the current value I of the current flowing through the secondary batteries B1 to Bn. (1) to I (n) are calculated.

Incidentally, the individual current calculation unit 105, based on the total resistance _{R total} internal resistance r (1) ~r (n) , the current value of the current flowing through the secondary battery B1~Bn I (1) ~I (N) may be calculated.

  The magnification calculation unit 112 is based on the individual resistance calculation unit 103 based on the total current I detected by the current detection unit 6 and the total voltage V detected by the voltage detection unit 7 during the period when the secondary battery Bm is discharged. When the resistance value is calculated, the internal resistance value rt associated with the SOC and temperature T of the secondary battery B at that time is calculated by the discharge lookup table LUT1 and the individual resistance calculation unit 103. The ratio with the internal resistance value r (m) is calculated as the discharge magnification Gd (m). That is, the magnification calculator 112 calculates the discharge magnifications Gd (1) to Gd (n).

  In addition, the magnification calculation unit 112 is based on the total current I detected by the current detection unit 6 and the total voltage V detected by the voltage detection unit 7 while the secondary battery Bm is charged. When the resistance value is calculated by 103, the internal resistance value rt associated with the SOC and the temperature T of the secondary battery B at that time by the charge lookup table LUT2 and the individual resistance calculation unit 103 A ratio with the calculated internal resistance value r (m) is calculated as a charging magnification Gc (m). That is, the magnification calculator 112 calculates the charging magnifications Gc (1) to Gc (n).

  Hereinafter, the discharge magnifications Gd (1) to Gd (n) are collectively referred to as the discharge magnification Gd, and the charge magnifications Gc (1) to Gc (n) are collectively referred to as the charge magnification Gc.

  Note that the magnification calculator 112 does not necessarily have to calculate the discharge magnification Gd (m) and the charge magnification Gc (m). For example, when the resistance value is calculated by the individual resistance calculation unit 103 based on the total current I and the total voltage V regardless of charging / discharging of the secondary battery Bm, the magnification calculation unit 112 is a lookup table. The ratio of the internal resistance value rt associated with the SOC and temperature T of the secondary battery Bm at that time by the LUT and the internal resistance value r (m) calculated by the individual resistance calculation unit 103 is expressed as a magnification G ( m) may be calculated.

  When the internal resistance value acquisition unit 113 acquires the internal resistance value of the secondary battery Bm during the period when the secondary battery Bm is discharged, the internal resistance value acquisition unit 113 associates the SOCm and the temperature Tm with the lookup table LUT1 for discharge. A multiplication value obtained by multiplying the internal resistance value rt by the discharge magnification Gd (m) is obtained as the internal resistance value r (m).

  Further, when the internal resistance value acquisition unit 113 acquires the internal resistance value of the secondary battery Bm while the secondary battery Bm is being charged, the internal resistance value acquisition unit 113 associates the SOCm and the temperature Tm with the lookup table LUT2 for charging. A multiplication value obtained by multiplying the internal resistance value rt thus obtained by the charging magnification Gc (m) is obtained as the internal resistance value r (m).

Thereby, the internal resistance value acquisition unit 113 acquires the internal resistance values r (1) to r (n). Further, the internal resistance value acquisition unit 113 may calculate the overall resistance value R _total from the internal resistance values r (1) to r (n) using the above equation (1).

  Note that the internal resistance value acquisition unit 113 sets the magnification G (m) to the internal resistance value rt associated with the SOCm and the temperature Tm by the lookup table LUT regardless of the charge / discharge of the secondary battery Bm. A multiplication value obtained by multiplication may be acquired as the internal resistance value r (m).

The total limit value calculation unit 106 sets the ratio of the internal resistance values r (1) to r (n) acquired by the internal resistance value acquisition unit 113 to p (1): p (2):. n), and based on the current upper limit values I _lim (1) to I _lim (n) and the ratios p (1) to p (n), the total upper limit value to limit the total current I flowing through the battery module 5 A limit value I _{lim_total} is calculated. Then, the overall limit value calculation unit 106 transmits the overall limit value I _{lim_total} to the charge / discharge control unit 21.

  The total limit value calculation unit 106 may use the internal resistance values r (1) to r (n) as the ratios p (1) to p (n) as they are. That is, p (1) = r (1), p (2) = r (2),..., P (n) = r (n) may be used.

  Next, the operation of the battery power supply system 3 configured as described above will be described. 2-8 is a flowchart which shows an example of operation | movement of the battery power supply device 1 shown in FIG. In the following flowchart, the same operation is given the same step number, and the description thereof is omitted. First, the discharge control unit 101 turns off the switching unit 41 and the switching element 43 in the initial state (step S1). Thereby, the battery module 5 is made into the state which is not charged / discharged.

  Next, the discharge control unit 101 checks whether or not an activation instruction signal from the charge / discharge control unit 21 has been received (step S2). If the activation instruction signal is received (YES in step S2), the process proceeds to step S101 in FIG. 3 to calculate the internal resistance value of the secondary battery B.

  In step S101, the individual resistance calculation unit 103 reads from the storage unit 107 the number mp of the secondary battery B for which the previous internal resistance value was calculated (step S101). The storage unit 107 stores the largest number among the numbers of the secondary batteries B whose internal resistance values have already been calculated. If no internal resistance value has been calculated yet, the storage unit 107 stores 0 as the number mp. Processing for storing the number mp in the storage unit 107 will be described later.

  Next, the individual resistance calculation unit 103 calculates the number m of the target secondary battery whose internal resistance value is to be calculated as m = mp + 1 (step S102). Hereinafter, calculation of the internal resistance value r (m) of the secondary battery Bm is executed.

  Next, the individual resistance calculation unit 103 turns on the switching element SWm and turns off all the switching elements SW other than the switching element SWm, that is, turns on only the switching element SWm, thereby setting the setting state m (step S103). .

  Next, the resistance calculation unit 104 acquires the value of the total current I detected by the current detection unit 6 as the current value I1, and acquires the value of the total voltage V detected by the voltage detection unit 7 as the voltage value V1. (Step S104).

Next, the discharge control unit 101 starts the discharge from the battery module 5 to the external device 2 by turning on the switching element 43 (step S105). As a result, the overall current I, which is the discharge current from the battery module 5, increases. At this time, the total current I discharged from the battery module 5 is limited to the current upper limit value I _{lim_min} or less by the resistor 44, so the discharge current of the secondary battery Bm exceeds the current upper limit value I _lim (m). Absent. Thereby, as a result of preventing an overcurrent from flowing through the secondary battery Bm, the possibility that the secondary battery Bm deteriorates is reduced.

  Next, the resistance calculation unit 104 acquires the value of the total current I detected by the current detection unit 6 as the current value I2, and acquires the value of the total voltage V detected by the voltage detection unit 7 as the voltage value V2. (Step S106). Then, the resistance calculation unit 104 calculates the difference between the current values I1 and I2 as the change amount dI of the overall current I, and calculates the difference between the voltage values V1 and V2 as the change amount dV of the overall voltage V (step S107).

  Here, the change amount dI and the change amount dV are generated in synchronization with the change of the discharge current due to the switching element 43 being turned on. FIG. 9 is an explanatory diagram showing an example of changes in the overall current I and the overall voltage V before and after the timing Ton when the switching element 43 is turned on. As shown in FIG. 9, when the switching element 43 is turned on at the timing Ton, an inrush current flows and the entire current I increases rapidly. At this time, a voltage drop due to the internal resistance of the secondary battery Bm occurs, and the overall voltage V decreases.

  Therefore, as shown in steps S104 to S106, the change amount dI and the change amount dV can be acquired by detecting the overall current I and the overall voltage V immediately before and after the switching element 43 is turned on. For example, the total current I and the total voltage V before and after the switching element 43 is turned on are monitored, and the amount of change at the peak of changes in the total current I and the total voltage V is expressed as the change amount dI and the change amount dV. You may make it acquire as.

Next, the resistance calculation unit 104 calculates a quotient obtained by dividing the change amount dV by the change amount dI as the resistance value R _mod of the battery module 5 (step S108).

Here, among the switching elements SW1 to SWn included in the battery module 5, only the switching element SWm corresponding to the secondary battery Bm is turned on. Therefore, the resistance value R _mod is the internal resistance value r (m). Is equal to Therefore, the resistance calculation unit 104 acquires the resistance value R _mod as the internal resistance value r (m) (step S109). As described above, the resistance calculation unit 104 calculates the internal resistance value r (m).

  Then, the individual resistance calculation unit 103 compares the number m with the number n of the secondary batteries B (step S110), and if m does not satisfy n (NO in step S110), the inside of all the secondary batteries B is still not inside. Since the resistance value is not calculated, the individual resistance calculation unit 103 sets the number m as mp (step S111) in the storage unit 107 so that the calculation of the internal resistance value of the remaining secondary battery B can be continued at the next opportunity. Store (step S113).

  On the other hand, if m is equal to n (YES in step S110), the internal resistance values r (1) to r (n) are calculated, so that the individual resistance calculation unit 103 starts again from the next opportunity. The number mp is set to zero (step S112) and stored in the storage unit 107 so that the internal resistance value is updated in order from the resistance value r (1) (step S113).

Next, the individual resistance calculation unit 103 turns on the switching elements SW1 to SWn (step S114). Thereby, the battery module 5 can flow the discharge current up to the total of the current upper limit values I _lim (1) to I _lim (n). As a result, there is no need to limit the total current I to the current upper limit value I _lim or less, so the discharge control unit 101 turns on the switching unit 41 (step S115).

  Next, in step S411 of FIG. 6, the magnification calculation unit 112 refers to the storage unit 107 and acquires the internal resistance value rt associated with the SOCm and the temperature Tm by the discharge lookup table LUT1 (step S411). S411). Then, the magnification calculator 112 calculates a quotient obtained by dividing the internal resistance value r (m) calculated by the individual current calculator 105 by the internal resistance value rt as a discharge magnification Gd (m) (step) S412), the process proceeds to step S5 in FIG.

  Here, the internal resistance value r (m) is the total current I detected by the current detector 6 and the voltage detector during the period when the secondary battery Bm is discharged by turning on the switching element 43 in step S105. 7 is a resistance value calculated by the individual current calculation unit 105 (and the resistance calculation unit 104) on the basis of the entire voltage V detected by 7.

  Specifically, in step S411, for example, when SOCm = 60 (%) and Tm = 40 ° C., rt = 9.765 (mΩ) is obtained from the discharge lookup table LUT1. At this time, when the internal resistance value r (m) = 19.53 (mΩ), Gd (m) = 19.53 / 9.765 = 2.

  Next, in step S5, the magnification calculation unit 112 checks whether or not the calculation of the discharge magnifications Gd (1) to Gd (n) and the charging magnifications Gc (1) to Gc (n) has been completed (step S5). S5). If there is a secondary battery B whose internal resistance value has not yet been calculated (NO in step S5), the process proceeds to step S2 again.

  In step S2, if the battery power supply device 1 has already been activated, there is no activation instruction signal (NO in step S2), and the process proceeds to step S3.

  In step S3, the charging control unit 102 determines whether or not to start charging (whether or not charging is necessary) (step S3). When the charging control unit 102 starts charging (YES in step S3), the individual resistance calculating unit 103 proceeds to step S201 in FIG. 4 to calculate the internal resistance value of the secondary battery B. On the other hand, when charging is not started (NO in step S3), charging control unit 102 proceeds to step S4.

Since the process of step S201-S204 is the same as that of step S101-S104, the description is abbreviate | omitted. In step S205, the charge control unit 102 reads the charge upper limit value Ic _lim from the storage unit 107, and _supplies the charge current to the charge / discharge control unit 21 with a charge current equal to or lower than the charge upper limit value Ic _lim , for example, equal to the charge upper limit value Ic _lim. An instruction signal requesting the supply of is output. Then, the charging / discharging control unit 21 outputs a charging current having a charging upper limit value Ic _lim .

  As a result, the overall current I (charging current) flowing through the battery module 5 changes, and a change in the overall voltage V occurs in synchronization with the change in the overall current I. Thereafter, by executing steps S206 to S214 similar to steps S106 to S114, the internal resistance value r (m) is calculated, and the switching elements SW1 to SWn are turned on.

At this time, since the charging current flowing through the secondary battery Bm does not exceed the charging upper limit value Ic _lim , the possibility that the secondary battery Bm deteriorates due to overcurrent is reduced. The charging control unit 102, in step S205, it is sufficient require less charging current charging upper limit value _{Ic lim,} not limited to the example requests the charging upper limit _{Ic lim.}

  Next, in step S521 in FIG. 7A, the magnification calculation unit 112 refers to the storage unit 107 and obtains the internal resistance value rt associated with the SOCm and the temperature Tm by using the charge lookup table LUT2. (Step S521). Then, the magnification calculation unit 112 calculates a quotient obtained by dividing the internal resistance value r (m) calculated by the individual current calculation unit 105 by the internal resistance value rt as a charging magnification Gc (m) (step) S522).

  Here, the internal resistance value r (m) is the total current I detected by the current detection unit 6 and the voltage detection unit during the period when the secondary battery Bm is charged when the charging current is requested in step S205. 7 is a resistance value calculated by the individual current calculation unit 105 (and the resistance calculation unit 104) on the basis of the entire voltage V detected by 7.

  Specifically, in step S521, for example, when SOCm = 60 (%) and Tm = 40 ° C., rt = 9.065 (mΩ) is obtained from the charge lookup table LUT2. At this time, assuming that the internal resistance value r (m) = 18.13 (mΩ), Gc (m) = 18.13 / 9.065 = 2.

Next, the charging control unit 102 increases the charging current (step S523). When the switching elements SW1 to SWn are turned on in step S214, the battery module 5 can accept the charging current up to n times the charging upper limit value Ic _lim . Therefore, for example, the charge control unit 102 outputs to the charge / discharge control unit 21 an instruction signal that requests supply of a charge current having a current value Icc set in advance as a charge current value for CC charging (constant current charging) ( Step S523). If it does so, since the charging current supplied to the battery module 5 will increase, charging time will be shortened.

In addition, after steps S204 to S208, the charge control unit 102 may execute step S208a for outputting an instruction signal for making the charging current zero to the charge / discharge control unit 21. Then, by repeating steps S204 to S208a a plurality of times, the charge / discharge control unit 21 causes the pulsed charging current to flow through the battery module 5 three times, and the resistance calculation unit 104 calculates the resistance value R _mod a plurality of times, The average value may be the internal resistance value r (m) in step S209. In this case, the calculation accuracy of the internal resistance value r (m) is improved.

  FIG. 10 is an explanatory diagram for explaining changes in the total current I and the total voltage V when Steps S204 to S208a are repeated three times. As shown in FIG. 10, when the total current I (charging current) is changed in steps S205 and S208a, the total voltage V changes in synchronization with the change of the total current I. The internal resistance value r (m) can be calculated based on the change between the total current I and the total voltage V.

  Thereafter, the charging control unit 102 continues the charging by the charging / discharging control unit 21 (NO in step S524), and when charging is completed (YES in step S524), the process proceeds to step S5.

When the charging control unit 102 does not start charging in step S3 (NO in step S3), the charging control unit 102 proceeds to step S4. In step S4, the individual resistance calculation unit 103 compares the total current I with the current determination value Ij (step S4). As the current determination value Ij, a value equal to or less than the current upper limit value I _{lim_min} is set in advance. If the total current I is equal to or less than the current determination value Ij, the individual resistance calculation unit 103 proceeds to step S301 in FIG. 5 to calculate the internal resistance value r, and the total current I exceeds the current determination value Ij. Then, the individual resistance calculation unit 103 proceeds to step S5 without calculating the internal resistance value r.

  In step S301 in FIG. 5, the individual resistance calculation unit 103 sets the number m to 1. Next, the individual resistance calculation unit 103 turns on the switching element SWm and turns off all the switching elements SW other than the switching element SWm, that is, turns on only the switching element SWm, thereby setting the setting state m (step S302). .

Here, step S302 is executed only when the total current I is _{equal to} or _smaller than the current upper limit value I _{lim_min} in step S4. Therefore, even if only the switching element SWm is turned on and the entire current I flows through the secondary battery Bm, the current flowing through the secondary battery Bm does not exceed the current upper limit value I _lim (m). Therefore, the possibility of degrading the secondary battery Bm is reduced.

  Next, the resistance calculation unit 104 acquires the value of the total current I detected by the current detection unit 6 as the current value I1, and acquires the value of the total voltage V detected by the voltage detection unit 7 as the voltage value V1. . Then, the resistance calculator 104 acquires a set of the current value I1 and the voltage value V1 as data D1 (step S303).

  Next, the resistance calculation unit 104 acquires, for example, the value of the total current I detected by the current detection unit 6 as the current value I2 after the elapse of a preset standby time after executing step S303, and the voltage The value of the entire voltage V detected by the detection unit 7 is acquired as the voltage value V2. And the resistance calculation part 104 acquires the group of the electric current value I2 and the voltage value V2 as the data D2 (step S304).

  As the standby time, for example, a time during which the state of charge / discharge control of the battery module 5 by the charge / discharge control unit 21 is likely to change and a change in the overall current I is likely to occur is, for example, a time of about 1 minute in advance. Is set.

  Next, the resistance calculation unit 104 acquires, for example, the value of the total current I detected by the current detection unit 6 as the current value I3 after the elapse of a preset standby time after executing step S304, and the voltage The value of the entire voltage V detected by the detection unit 7 is acquired as the voltage value V3. Then, the resistance calculator 104 acquires a set of the current value I3 and the voltage value V3 as data D3 (step S305).

  Next, the resistance calculation unit 104 generates a regression line L from the data D1, D2, and D3 (step S306), and acquires the slope of the regression line L as the internal resistance value r (m) (step S307).

  FIG. 11 is an explanatory diagram for explaining an example of a method for calculating the internal resistance value r (m) by the resistance calculation unit 104. FIG. 11A shows an example in which steps S303 to S305 are executed while the secondary battery Bm is being discharged, and FIG. 11B shows that steps S303 to S305 are being charged to the secondary battery Bm. Shows an example when it is executed.

  As shown in FIGS. 11A and 11B, the resistance calculation unit 104 generates a regression line L that passes through the points indicated by the data D1, D2, and D3, which is a set of a plurality of data. The regression line L thus obtained is expressed by the following equation (2), and a coefficient R indicating the slope is obtained as the internal resistance value r (m) of the secondary battery Bm.

V = R × I + V ₀ (2)
In order to obtain the regression line L, it is necessary to acquire a set of a plurality of total voltages V and total currents I having different values. However, for example, in an electric vehicle, the charge / discharge current frequently changes according to the acceleration / deceleration of the vehicle, the road surface condition, and the like. Therefore, for example, in a period of about 1 minute, it is possible to acquire a set of a plurality of total voltages V and total currents I, which are different from each other, necessary for obtaining the regression line L.

  Although the example in which the number of data sets is three sets of data D1, D2, and D3 has been shown, the number of data sets is not limited to three, and it is sufficient if there are two or more sets.

  Next, whether or not the data D1, D2, and D3 are data acquired during discharging of the secondary battery Bm by the magnification calculator 112, that is, whether or not the current values I1, I2, and I3 are all negative values. Is confirmed (step S371). If the current values I1, I2, and I3 are all negative values (YES in step S371), the magnification calculator 112 proceeds to step S411 in FIG. 6 and executes steps S411 and S412. The process proceeds to step S308 of step 5.

  On the other hand, if at least one of the current values I1, I2, and I3 is a positive value (NO in step S371), the magnification calculator 112 acquires the data D1, D2, and D3 during the discharge of the secondary battery Bm. Whether the current values I1, I2, and I3 are all positive values (step S372). If the current values I1, I2, and I3 are all positive values (YES in step S372), the data D1, D2, and D3 are data acquired during the charging of the secondary battery Bm, so the magnification calculation is performed. The unit 112 proceeds to step S521 in FIG. 7B, executes steps S521 and S522, and then proceeds to step S308 in FIG.

  In step S308, the individual resistance calculation unit 103 compares the number m with the number n of the secondary batteries B (step S308), and if m does not satisfy n (NO in step S308), all the secondary batteries B are still present. Since the internal resistance value is not calculated, the individual resistance calculation unit 103 adds 1 to the number m (step S309) and repeats steps S302 to S372 again.

  On the other hand, if m is equal to n (YES in step S308), the internal resistance values r (1) to r (n) are calculated, and thus the individual resistance calculation unit 103 ends the calculation of the internal resistance value. Then, the switching elements SW1 to SWn are turned on (step S310), and the process proceeds to step S5 in FIG.

  As described above, the internal resistance values r (1) to r (2) of the secondary batteries B1 to Bn included in the battery module 5 by the processes of steps S1 to S5, S101 to S115, S201 to S214, S523, S524, and S301 to S310. n) can be detected. And since the current detection part required in order to detect internal resistance value r (1) -r (n) may be one current detection part, it is required in order to detect the internal resistance value of a secondary battery. Thus, the number of current detection units can be smaller than the number of secondary batteries connected in parallel.

  Further, the discharge magnifications Gd (1) to Gd (n) and the charge magnifications Gc (1) to Gc (n) are calculated by the processes in steps S411, S412, S521, and S522.

  In step S5, the magnification calculation unit 112 confirms whether or not the calculation of the discharge magnifications Gd (1) to Gd (n) and the charge magnifications Gc (1) to Gc (n) has been completed, and the discharge magnification Gd (1 ) To Gd (n) and the charging magnifications Gc (1) to Gc (n) are completed (YES in step S5), the internal resistance value acquisition unit 113 performs the subsequent internal resistance value r (1). The process proceeds to step S721 in FIG. 8 to perform ~ r (n).

  In step S721, the internal resistance value acquiring unit 113 checks whether or not the overall current I is less than 0, that is, whether or not the battery module 5 is in a discharged state (step S721). If the total current I is less than 0 (YES in step S721), the internal resistance value acquiring unit 113 refers to the discharge lookup table LUT1, and determines the internal resistance based on SOC1 to SOCn and T1 to Tn. Values rt (1) to rt (n) are acquired (step S722).

  Next, the internal resistance value acquisition unit 113 calculates the internal resistance value r (m) by multiplying the internal resistance value rt (m) by the discharge magnification Gd (m) for m of 1 to n (step) S723).

  Specifically, in step S722, for example, when SOCm = 40 (%) and Tm = 40 ° C., the internal resistance value rt (m) = 8.92 (mΩ) is obtained from the discharge lookup table LUT1. . Here, if the discharge magnification Gd (m) = 2, the internal resistance value r (m) = 8.92 × 2 = 17.84 (mΩ). For example, when SOCm = 60 (%) and Tm = 20 ° C., the internal resistance value rt (m) = 14.75 (mΩ) is obtained from the lookup table LUT1 for discharge. Here, if the discharge magnification Gd (m) = 2, the internal resistance value r (m) = 14.75 × 2 = 29.5 (mΩ).

  On the other hand, if the total current I is greater than or equal to 0 in step S721 (NO in step S721), the internal resistance value acquiring unit 113 refers to the charge lookup table LUT2 and determines SOC1 to SOCn and T1 to Tn. Based on this, internal resistance values rt (1) to rt (n) are acquired (step S724).

  Next, the internal resistance value acquisition unit 113 calculates the internal resistance value r (m) by multiplying the internal resistance value rt (m) by the charging magnification Gc (m) for m in the range of 1 to n. (Step S725).

  Specifically, in step S724, for example, when SOCm = 40 (%) and Tm = 40 ° C., the internal resistance value rt (m) = 8.820 (mΩ) is obtained from the charge lookup table LUT2. . Here, if the charging magnification Gc (m) = 2, the internal resistance value r (m) = 8.820 × 2 = 17.64 (mΩ). For example, when SOCm = 60 (%) and Tm = 20 ° C., the internal resistance value rt (m) = 13.100 (mΩ) is obtained from the charge lookup table LUT2. Here, if the charging magnification Gc (m) = 2, the internal resistance value r (m) = 13.100 × 2 = 26.200 (mΩ).

  As described above, the internal resistance value r (m) of the secondary battery Bm is obtained by the processing in steps S721 to S725. In this case, the internal resistance value r (m) of the secondary battery Bm is calculated based on the temperature Tm, SOCm of the secondary battery Bm, and whether the secondary battery Bm is discharging or charging. As a result of calculating the internal resistance value r (m) in consideration of the influence of the temperature, the influence of the SOC, and the influence of the charge / discharge state of the secondary battery, the calculation accuracy of the internal resistance value r (m) is improved.

  Next, the individual current calculation unit 105 proceeds to step S6 to calculate the current flowing through the secondary batteries B1 to Bn.

  In step S6, the individual current calculation unit 105 uses the following equation (3) based on the internal resistance values r (1) to r (n) acquired by the internal resistance value acquisition unit 113 and the total current I. Then, current values I (1) to I (n) of the currents flowing through the secondary batteries B1 to Bn are calculated.

  The individual current calculation unit 105 may calculate all the current values I (1) to I (n), where m is 1 to n, and calculates only the current value I (m) flowing through any secondary battery Bm. May be.

Note that the individual current calculation unit 105 causes the internal resistance value acquisition unit 113 to calculate the above-described total resistance value R _total, and determines the internal resistance values r (1) to r (n), the total resistance value R _total, and the total current. Based on I, current values I (1) to I (n) of currents flowing in the secondary batteries B1 to Bn may be calculated using the following formula (4).

I (m) = {R _total / r (m)} × I (4)
Using formulas (3) and (4), the individual current calculation unit 105 may calculate all the current values I (1) to I (n), where m is 1 to n, and any secondary battery. Only the current value I (m) flowing through Bm may be calculated.

Next, the overall limit value calculation unit 106 sets the ratio of the internal resistance values r (1) to r (n) acquired by the internal resistance value acquisition unit 113 to p (1): p (2):. Calculated as p (n) (step S7). Then, the total limit value calculation unit 106 uses the formula (5) based on the ratios p (1) to p (n) and the current upper limit values I _lim (1) to I _lim (n) to determine the total limit value. _{Ilim_total} is calculated (step S8).

In step S7, the total limit value calculation unit 106 causes the internal resistance value acquisition unit 113 to calculate the _total resistance value R _total described above, and sets the ratio between R _total and the internal resistance value r (m) to P _total : P (M) (m is an integer of 1 to n). In step S8, the total resistance value _Rtotal , the ratios P (1) to P (n), and the current upper limit values I _lim (1) to I _lim ( On the basis of n), the overall limit value I _{lim_total} may be calculated using Equation (6).

Next, the individual current calculation unit 105 transmits the current values I (1) to I (n) to the charge / discharge control unit 21, and the total limit value calculation unit 106 transmits the total limit value I _{lim_total} to the charge / discharge control unit 21. (Step S9), the process proceeds to Step S721.

Thereby, the charge / discharge control unit 21 can monitor the current values I (1) to I (n) of the current flowing through the secondary batteries B1 to Bn only by providing one current detection unit 6. Become. In addition, the charge / discharge control unit 21 limits the current amount to be discharged by the battery module 5 to the overall limit value I _{lim_total} or less, thereby _changing the current values I (1) to I (n) to the current upper limit value I _lim (1 ) To I _lim (n) or less. As a result, the possibility that the secondary batteries B1 to Bn are deteriorated due to overcurrent can be reduced.

Further, based on the internal resistance values r (1) to r (n) calculated by the internal resistance value acquisition unit 113 in consideration of the influence of temperature, the influence of SOC, and the influence of the charge / discharge state of the secondary battery, Since the current values I (1) to I (n) and the overall limit value I _{lim_total} are calculated, the calculation accuracy of the current values I (1) to I (n) and the overall limit value I _{lim_total} is improved.

Thereafter, the calculation of the internal resistance values r (1) to r (n), the current values I (1) to I (n), and the overall limit value I _{lim_total} is repeated by repeating _{steps S721 to S9.} Is updated to the latest value in accordance with changes in the temperature and SOC of the secondary battery B.

  The internal resistance values r (1) to r (n), the discharge magnifications Gd (1) to Gd (n), and the charge magnifications Gc (1) to Gc (n) change as the secondary battery B deteriorates. Therefore, for example, when a power switch or ignition switch (not shown) is turned off and then the power switch or ignition switch is turned on again to start up the apparatus, or periodically from step S1 every predetermined period. The execution is started, and the discharge magnifications Gd (1) to Gd (n) and the charge magnifications Gc (1) to Gc (n) are newly calculated and updated.

  The individual resistance calculation unit 103 calculates the internal resistance values r (1) to r (n) by the processes of steps S401 to S516 shown in FIGS. 12 and 13 instead of steps S101 to S115 shown in FIG. May be.

First, shifts from step S2 to step S401 (YES in step S2), the the processing of step S401 to S407, calculates the total resistance _{R total.}

  Specifically, the individual resistance calculation unit 103 turns on the switching elements SW1 to SWn in step S401. Hereinafter, the processing of steps S402 to S406 is the same as that of steps S104 to S108, and thus the description thereof is omitted.

The resistance calculation unit 104 acquires the resistance value R _mod calculated in step S406 as the overall resistance value R _total (step S407), and proceeds to step S501 in FIG. Steps S501, S502, S504 to S508, and S511 to S516 are the same as steps S101, S102, S104 to S108, and S110 to S115, and thus the description thereof is omitted.

  In step S503, the individual resistance calculation unit 103 turns off the switching element SWm and turns on all the switching elements SW other than the switching element SWm, that is, turns off only the switching element SWm, thereby setting the setting state m (step S503). ).

In this case, when the switching element 43 is turned on in step S505, the battery module 5 has a current upper limit value obtained by removing the current upper limit value I _lim (m) from the current upper limit values I _lim (1) to I _lim (n). It is possible to pass a current corresponding to the total. The current upper limit values I _lim (1) to I _lim (n) are considered to be substantially the same current upper limit value I _lim . Therefore, by turning off only the switching element SWm in step S503, the resistance value of the resistor 44 is changed to the inrush current flowing from the battery module 5 to the external device 2 when the switching element 43 is turned on to the current upper limit value I _lim . A resistance value equal to or higher than the resistance value limited to the current corresponding to the value multiplied by (n-1) can be obtained. That is, since the resistance value of the resistor 44 can be made smaller than when only the switching element SWm is turned on, the degree of freedom in designing the resistance value of the resistor 44 is increased.

The individual resistance calculation unit 103 acquires the resistance value R _mod calculated by the resistance calculation unit 104 in step S508 as the partial resistance value Rb (step S509). Then, the individual resistance calculator 103 calculates an internal resistance value r (m) using the following equation (7) based on the overall resistance value _Rtotal and the partial resistance value Rb (step S510).

r (m) = (Rb × R _total ) / (Rb−R _total ) (7)
As described above, the internal resistance values r (1) to r (n) can also be calculated by the processing in steps S401 to S516.

  Further, the individual current calculation unit 105 may calculate the internal resistance values r (1) to r (n) by the processes of steps S601 to S615 shown in FIG. 14 instead of steps S201 to S214 shown in FIG. Good. In the processing of steps S601 to S615, the internal resistance values r (1) to r (n) are calculated by setting the switching element SW to a setting state in which only one switching element SW is turned off. Since the processes of steps S601, S602, S604, S606 to S608, and S611 to S615 are the same as steps S201, S202, S204, S206 to S208, and S210 to S214, description thereof will be omitted.

  In step S603, the individual resistance calculation unit 103 turns off the switching element SWm and turns on all the switching elements SW other than the switching element SWm, that is, turns off only the switching element SWm, thereby setting the setting state m (step S603). ).

In step S605, the charging control unit 102 reads the charging upper limit value Ic _lim from the storage unit 107, and sends the charging upper limit value Ic _lim to the charging / discharging control unit 21 in a range not exceeding (n-1) times the charging upper limit value Ic _lim. An instruction signal for requesting the supply of the set charging current is output. Then, the charging / discharging control unit 21 outputs a charging current corresponding to the instruction signal from the charging control unit 102. In this case, it is possible to increase the charging current as compared with step S205.

The individual resistance calculation unit 103 acquires the resistance value R _mod calculated by the resistance calculation unit 104 in step S608 as the partial resistance value Rb (step S609). Then, the individual resistance calculation unit 103 calculates the internal resistance value r (m) by the same process as in step S510 (step S610). Incidentally, in step S610, the individual resistance calculating unit 103 may use a total resistance _{R total} calculated in step S407. In addition, the individual resistance calculation unit 103 uses the resistance value R _mod obtained by executing steps S603 to S608 as the overall resistance value R _{total in} the setting state in which all the switching elements SW1 to SWn are turned on in step S603. May be.

  As described above, the internal resistance values r (1) to r (n) can also be calculated by the processing in steps S601 to S615.

  Further, the individual resistance calculation unit 103 may calculate the internal resistance values r (1) to r (n) by the processes of steps S701 to S711 shown in FIG. 15 instead of steps S301 to S310 shown in FIG. Good. In the processing of steps S701 to S711, the internal resistance values r (1) to r (n) are calculated by setting a state in which only one switching element SW is turned off. Since the processes of steps S701, S703 to S706, S371, S372, and S709 to S711 are the same as steps S301, S303 to S306, S371, S372, and S308 to S310, description thereof is omitted.

  In step S702, the individual resistance calculation unit 103 turns off the switching element SWm and turns on all the switching elements SW other than the switching element SWm, that is, turns off only the switching element SWm, thereby setting the setting state m (step S702). ).

In this case, the battery module 5 can flow a current corresponding to the sum of the current upper limit values obtained by removing the current upper limit value I _lim (m) from the current upper limit values I _lim (1) to I _lim (n). . The current upper limit values I _lim (1) to I _lim (n) are considered to be substantially the same current upper limit value I _lim . Therefore, according to the process of step S702, it is possible to set a value equal to or less than a multiplication value obtained by multiplying the current upper limit value _Ilim by (n-1) as the current determination value Ij in step S4. By setting a value equal to or less than a multiplication value obtained by multiplying the current upper limit value I _lim by (n−1), the current determination value Ij is set as compared with a case where a value equal to or less than the current upper limit value I _lim is set as the current determination value Ij. Can be increased, so that opportunities for calculating the internal resistance values r (1) to r (n) can be increased.

The individual resistance calculation unit 103 acquires the slope of the regression line L generated by the resistance calculation unit 104 in step S706, that is, the resistance value of the battery module 5 as the partial resistance value Rb (step S707). Then, the individual resistance calculation unit 103 calculates the internal resistance value r (m) by the same process as in step S510 (step S708). Note that, in step S 708, the individual resistance calculating unit 103 may use a total resistance _{R total} calculated in step S407. Further, the individual resistance calculating unit 103, the setting state in which all turn on the switching element SW1~SWn In step S702, the slope of the regression line L obtained by performing step S702～S706, total resistance _{R total} It may be used as

  As described above, the internal resistance values r (1) to r (n) can also be calculated by the processing in steps S701 to S711.

  Further, the individual resistance calculation unit 103 may calculate the internal resistance values r (1) to r (n) by the processes of steps S801 to S816 shown in FIG. 16 instead of steps S301 to S310 shown in FIG. Good. In the processes of steps S801 to S816, the internal resistance values r (1) to r (n) are calculated by setting the switching elements SW to be turned on one by one in order. The processes in steps S801 to S806 are the same as those in steps S301 to S306, and the processes in steps S807, S814, and S816 are the same as those in steps S707, S709, and S711.

  In step S808, the individual resistance calculation unit 103 checks whether the number m is 1 (step S808). If the number m is 1 (YES in step S808), since the first partial resistance value Rs has not yet been calculated, the individual resistance calculation unit 103 proceeds to step S809 and uses the partial resistance value Rb as the internal resistance value r. The internal resistance value r (m) is obtained by setting (m), and the first partial resistance value Rs is obtained by setting the partial resistance value Rb to the first partial resistance value Rs (step S809). After adding (step S810), the process proceeds to step S811.

  In step S811, the individual resistance calculation unit 103 turns on the switching element SWm, that is, increases the number of switching elements SW that are turned on one by one to set the state m (step S811), and repeats steps S803 to S808 again. .

  Next, if the number m is not 1 in step S808 (NO in step S808), the individual resistance calculation unit 103 sets the second partial resistance value Rp by setting the partial resistance value Rb to the second partial resistance value Rp. Obtained (step S812), based on the first partial resistance value Rs and the second partial resistance value Rp, the internal resistance value r (m) is calculated based on the following equation (8) (step S813).

Internal resistance value r (m) = (Rs × Rp) / (Rs−Rp) (8)
The individual resistance calculation unit 103 compares the number m with the number n of the secondary batteries B (step S814). If m does not satisfy n (NO in step S814), the internal resistance values of all the secondary batteries B are still present. Therefore, the individual resistance calculation unit 103 obtains the first partial resistance value Rs by setting the second partial resistance value Rp as the new first partial resistance value Rs (step S815), and steps S810 to S814. repeat.

  On the other hand, if m is equal to n (YES in step S814), since the internal resistance values r (1) to r (n) are calculated, the individual resistance calculation unit 103 ends the calculation of the internal resistance value. Then, the switching elements SW1 to SWn are turned on (step S816), and the process proceeds to step S5.

  As described above, the internal resistance values r (1) to r (n) can also be calculated by the processing in steps S801 to S816.

  Further, the individual resistance calculation unit 103 may calculate the internal resistance values r (1) to r (n) by the processing of steps S901 to S916 shown in FIG. 17 instead of steps S301 to S310 shown in FIG. Good. In the processing of steps S901 to S916, the internal resistance values r (1) to r (n) are calculated by setting the switching elements SW to be turned off one by one in order. The processes in steps S903 to S906 are the same as those in steps S303 to S306, and the processes in steps S907, S913, S914, and S916 are the same as those in steps S807, S813, S814, and S816.

  In step S901, the individual resistance calculation unit 103 sets the number m to zero (step S901) and turns on the switching elements SW1 to SWn (step S902).

  In step S908, the individual resistance calculation unit 103 checks whether the number m is 0 (step S908). If the number m is 0 (YES in step S908), since the second partial resistance value Rp has not yet been calculated, the individual resistance calculation unit 103 proceeds to step S909 and sets the partial resistance value Rb to the second partial resistance. The second partial resistance value Rp is obtained by setting the value Rp (step S909), 1 is added to the number m (step S910), and the process proceeds to step S911.

  In step S911, the individual resistance calculation unit 103 turns off the switching element SWm, that is, increases the number of switching elements SW that are turned off by one to set the state m (step S911), and repeats steps S903 to S908 again.

  Next, in step S908, if the number m is not 0 (NO in step S908), the individual resistance calculation unit 103 sets the first partial resistance value Rs by setting the partial resistance value Rb to the first partial resistance value Rs. Obtained (step S912), based on the first partial resistance value Rs and the second partial resistance value Rp, the internal resistance value r (m) is calculated based on the above equation (8) (step S913).

  The individual resistance calculation unit 103 compares the number m with the number n of the secondary batteries B (step S914), and if m does not satisfy n (NO in step S914), the internal resistance values of all the secondary batteries B are still present. Therefore, the individual resistance calculation unit 103 obtains the second partial resistance value Rp by setting the first partial resistance value Rs as the new second partial resistance value Rp (step S915), and steps S910 to S914. repeat.

  On the other hand, if m is equal to n (YES in step S914), the internal resistance values r (1) to r (n) are calculated, and thus the individual resistance calculation unit 103 ends the calculation of the internal resistance value. Then, the switching elements SW1 to SWn are turned on (step S916), and the process proceeds to step S5.

  As described above, the internal resistance values r (1) to r (n) can also be calculated by the processing in steps S901 to S916.

  The internal resistance detection circuit 4 may be configured not to execute steps S2, S101 to S115, and S401 to S516. Alternatively, the internal resistance detection circuit 4 may be configured not to execute steps S3, S201 to S216, and S601 to S617. Or the internal resistance detection circuit 4 is good also as a structure which does not perform step S4, S301-S310, S701-S711, S801-S916. Alternatively, the internal resistance detection circuit 4 may be configured not to execute step S6. Alternatively, the internal resistance detection circuit 4 may be configured not to execute steps S7 and S8.

(Second Embodiment)
Next, an internal resistance detection circuit 4a according to a second embodiment of the present invention and a battery power supply system 3a including the battery power supply device 1a including the same will be described. FIG. 18 is a block diagram showing an example of the configuration of the battery power supply system 3a according to the second embodiment of the present invention. The battery power supply system 3a shown in FIG. 18 differs from the battery power supply system 3 shown in FIG. 1 in that the battery module 5a does not include the switching element SW1 and the operation of the individual resistance calculation unit 103a.

  Since the other configuration is the same as that of the battery power supply system 3 shown in FIG. 1, the configuration given the same reference numerals as those in FIG. 1 in FIG. 18 indicates the same configuration, and the description thereof is omitted. Hereinafter, characteristic points of the battery power supply device 1a will be described.

  The battery module 5a does not include the switching element SW1, and the wiring 52 is directly connected to one terminal (for example, a positive electrode terminal) of the secondary battery B1. The secondary battery B1 corresponds to an example of a basic secondary battery.

  FIGS. 19-24 is a flowchart which shows an example of operation | movement of the battery power supply system 3a. In the following flowcharts, operations similar to those in the flowcharts described above are denoted by the same step numbers, and description thereof is omitted. First, steps S1 to S5 shown in FIG. 2 and steps S721 to S725 and S6 to S9 shown in FIG. 8 are the same in the battery power supply system 3a.

  After shifting from step S2 in FIG. 2 to step S101 in FIG. 19 (YES in step S2), the same steps S101 and S102 as in FIG. 3 are executed, and then in step S121, the individual resistance calculation unit 103a has the number m. It is confirmed whether or not 1 (step S121). If the number m is 1 (YES in step S121), the individual resistance calculation unit 103a turns off the switching elements SW2 to SWn, and only the secondary battery B1 is connected in the battery module 5a (step). S122).

Hereinafter, after steps S104 to S108 are executed, the individual resistance calculation unit 103a acquires the resistance value R _mod as the internal resistance value r (1) (step S123). Thereafter, steps S111 and S113 to S115 are executed, and the process proceeds to step S411 shown in FIG.

  On the other hand, if the number m is not 1 in step S121 (NO in step S121), since the internal resistance value r (1) has already been calculated, the individual resistance calculation unit 103a proceeds to step S103 shown in FIG. To do. When step S103 in FIG. 20 is executed, the battery module 5a becomes a parallel circuit of the secondary battery B1 and the secondary battery Bm.

Thereafter, after steps S104 to S108 are executed, the individual resistance calculation unit 103a uses the following equation (9) based on the internal resistance value r (1) and the resistance value R _mod to determine the internal resistance value r (m ) Is calculated (step S125). The resistance value R _mod corresponds to a partial resistance value.

r (m) = (r (1) × R _mod ) / (r (1) −R _mod ) (9)
Thereafter, steps S110 to S115 are executed to calculate the internal resistance values r (1) to r (n). Then, the process proceeds from step S115 to step S411 shown in FIG.

  As described above, the battery power supply device 1a detects the internal resistance values r (1) to r (n) by the processing shown in FIGS. 19 and 20 as in the case of the battery power supply device 1 shown in FIG. For this purpose, only one current detection unit is required. Furthermore, the battery power supply device 1 a can reduce the number of switching elements SW by one as compared with the battery power supply device 1.

  Further, after moving from step S3 in FIG. 2 to step S201 in FIG. 21 (YES in step S3), steps S201 and S202 similar to those in FIG. 4 are executed. Next, in step S221, the individual resistance calculation unit 103a It is confirmed whether the number m is 1 (step S221). If the number m is 1 (YES in step S221), the individual resistance calculation unit 103a turns off the switching elements SW2 to SWn, and only the secondary battery B1 is connected in the battery module 5a (step). S222).

Thereafter, Steps S204 to S214 are executed, and after the resistance value R _mod is acquired as the internal resistance value r (1) by the individual resistance calculation unit 103a, the process proceeds to Step S521 in FIG.

  On the other hand, if the number m is not 1 in step S221 (NO in step S221), the internal resistance value r (1) has already been calculated, and the individual resistance calculation unit 103a proceeds to step S203 shown in FIG. To do. When step S203 in FIG. 22 is executed, the battery module 5a becomes a parallel circuit of the secondary battery B1 and the secondary battery Bm.

Hereinafter, after steps S204 to S208 are executed, the individual resistance calculation unit 103a uses the above-described equation (9) based on the internal resistance value r (1) and the resistance value R _mod to determine the internal resistance value r (m ) Is calculated (step S225). The resistance value R _mod corresponds to a partial resistance value.

  Thereafter, steps S210 to S214a are executed to calculate the internal resistance values r (1) to r (n), and then the process proceeds to step S521 in FIG.

  21 and 22, the current detection necessary for the battery power supply device 1a to detect the internal resistance values r (1) to r (n) is the same as the battery power supply device 1 shown in FIG. The unit is one current detection unit. Furthermore, the battery power supply device 1 a can reduce the number of switching elements SW by one as compared with the battery power supply device 1.

  Further, after the transition from step S4 in FIG. 2 to step S301 in FIG. 23 (YES in step S4), step S301 similar to FIG. 5 is executed, and then in step S302a, the individual resistance calculation unit 103a All the switches SW2 to SWn are turned off to set the setting state m (step S302a).

  Thereafter, steps S303 to S306 are executed, and in step S307a, the individual resistance calculation unit 103a acquires the slope of the regression line L as the internal resistance value r (1) (step S307a), and steps S371 and S372 are executed. When the process proceeds from step S371 to step S411 in FIG. 6 (YES in step S371), the process proceeds to step S308 in FIG. 24 after step S412. When the process proceeds from step S372 to step S521 in FIG. 7B (YES in step S372), the process proceeds to step S308 in FIG. 24 after step S522.

Thereafter, steps S308, S309, and S302 to S306 are executed, and then the individual resistance calculation unit 103a acquires the slope of the regression line L as the resistance value R _mod (step S321), and step S225 is executed to determine the internal resistance value r. (M) is calculated.

  After step S225, steps S371 and S372 are executed. When the process proceeds from step S371 to step S411 in FIG. 6 (YES in step S371), the process proceeds to step S308 in FIG. 24 after step S412. When the process proceeds from step S372 to step S521 in FIG. 7B (YES in step S372), the process proceeds to step S308 in FIG. 24 after step S522.

  Hereinafter, after steps S308 to S225, S371, and S372 are repeated until the internal resistance values r (2) to r (n) are calculated, the switching elements SW2 to SWn are turned on (step S310a), and the process proceeds to step S5. Transition.

  23 and 24, the current detection necessary for the battery power supply 1a to detect the internal resistance values r (1) to r (n) is the same as the battery power supply 1 shown in FIG. The unit is one current detection unit. Furthermore, the battery power supply device 1 a can reduce the number of switching elements SW by one as compared with the battery power supply device 1.

  Further, the battery power supply device 1a may calculate the internal resistance value r (1) by setting a state in which only one switching element SW2 to SWn is turned off. The battery power supply device 1a turns on the switching elements SW2 to SWn in steps S401 and S515 in the processing of steps S401 to S516 in FIGS. 12 and 13, and step S401 is performed only when the number m is 2 to n. The internal resistance values r (2) to r (n) may be calculated by executing the process of ~ S516. Then, the individual resistance calculation unit 103a calculates the combined resistance value Rc when the internal resistance values r (2) to r (n) are connected in parallel based on the following equation (10).

Rc = 1 / {(1 / r (2)) + (1 / r (3)) +... + (1 / r (n))} (10)
Then, the individual resistance calculation unit 103a may calculate the internal resistance value r (1) based on the following equation (11).

r (1) = (Rc × R _total ) / (Rc−R _total ) (11)
Similarly, in the processing of steps S601 to S615 in FIG. 14 and steps S521 to S524 in FIG. 7, the battery power supply device 1a turns on the switching elements SW2 to SWn in step S615, and the number m is 2 to n. Only for the case, the processes of steps S601 to S615 and steps S521 to S524 of FIG. 7 may be executed to calculate the internal resistance values r (2) to r (n). Then, the individual resistance calculation unit 103a may calculate the internal resistance value r (1) using the above equations (10) and (11).

  Similarly, in the process of steps S701 to S711 in FIG. 15, the battery power supply device 1a sets m = 2 in step S701, turns on the switching elements SW2 to SWn in step S711, and the number m is 2 to n. Only for the case, the processing in steps S701 to S711 may be executed to calculate the internal resistance values r (2) to r (n). Then, the individual resistance calculation unit 103a may calculate the internal resistance value r (1) using the above equations (10) and (11).

  Similarly, in the processing of steps S801 to S816 in FIG. 16, the battery power supply device 1a turns off the switching elements SW2 to SWn only when m = 1 in step S802, and directly performs step S802 when m = 2 to n. In step S816, the internal resistance values r (1) to r (n) may be calculated by turning on the switching elements SW2 to SWn.

  Similarly, in the process of steps S901 to S916 in FIG. 17, the battery power supply device 1a determines whether m = n + 1 in step S901, m = n + 1 in step S908, and m = m−1 in step S910. In step S916, the internal resistance values r (1) to r (n) may be calculated by turning on the switching elements SW2 to SWn.

  The internal resistance detection circuit 4a may be configured not to execute steps S2, S101 to S115, and S401 to S516. Or the internal resistance detection circuit 4a is good also as a structure which does not perform step S3, S201-S214, S521-S524, S601-S615, and S521-S524. Or the internal resistance detection circuit 4a is good also as a structure which does not perform step S4, S301-S310, S701-S711, S801-S916. Alternatively, the internal resistance detection circuit 4a may be configured not to execute step S6. Alternatively, the internal resistance detection circuit 4a may be configured not to execute steps S7 and S8.

  Moreover, although the example in which the charging / discharging control part 21 is provided in the external device 2 was shown, it is good also as a structure by which the battery power supply devices 1 and 1a are provided with the charging / discharging control part 21, for example.

  An internal resistance detection circuit according to the present invention and a battery power supply device including the same are provided as electronic devices such as portable personal computers, digital cameras and mobile phones, vehicles such as electric vehicles and hybrid cars, hybrid elevators, solar cells and power generation devices. Can be suitably used in battery-mounted devices and systems such as a power supply system in which a battery and a secondary battery are combined, and a non-disruptive power supply device.

DESCRIPTION OF SYMBOLS 1, 1a Battery power supply device 2 External device 3, 3a Battery power supply system 4, 4a Internal resistance detection circuit 5, 5a Battery module 6 Current detection part 7, Z, Z1-Zn Voltage detection part X, X1-Xn Temperature sensor 10 Control Unit 11, 24 Communication unit 15, 16, 17, 25, 26, 27 Connection terminal 21 Charge / discharge control unit 22 Power generation device 23 Load device 41 Switching unit 42 Current limiting unit 43 Switching element 44 Resistor 51 Single cell 52, 53 Wiring 101 Discharge control unit 102 Charge control unit 103, 103a Individual resistance calculation unit 104 Resistance calculation unit 105 Individual current calculation unit 106 Overall limit value calculation unit 107 Storage unit 111 Detection unit 112 Magnification calculation unit 113 Internal resistance value acquisition units B, B1 to Bn , Bm secondary battery I total current I (1) ~I (n) the current value I1, I2, I3 current value Icc current value _{Ic li} Charging limit _{I lim (1) ~I lim (} n) current limit _{I Lim_total} overall limit L regression line r (1) ~r (n) the internal resistance Rb partial resistance value Rc combined resistance value re internal resistance value R _mod resistance value Rp second partial resistance value Rs first partial resistance value R _total overall resistance value SW, SW1 to SWn switching element T, T1 to Tn temperature V overall voltage V1, V2, V3 voltage value V _end discharge end voltage

Claims (29)

A current detection unit for detecting a current flowing in the secondary battery;
A voltage detector for detecting the voltage of the secondary battery;
A temperature detector for detecting the temperature of the secondary battery;
A charge state detection unit for detecting a charge state of the secondary battery;
Based on the current detected by the current detector and the voltage detected by the voltage detector, an individual resistance calculator that calculates a resistance value of the secondary battery;
A storage unit that pre-stores the charge state and temperature of the secondary battery and the internal resistance value of the secondary battery in association with each other;
The internal resistance value stored in the storage unit corresponding to the charge state and temperature of the secondary battery whose resistance value has been calculated by the individual resistance calculation unit, and the resistance calculated by the individual resistance calculation unit A magnification calculation unit for calculating a ratio with a value as a magnification;
Internal resistance stored in the storage unit in association with the state of charge detected by the state of charge detection unit and the temperature detected by the temperature detection unit after the resistance value is calculated by the resistance calculation unit An internal resistance detection circuit comprising: an internal resistance value acquisition unit that acquires a multiplication value obtained by multiplying the value by the magnification as an internal resistance value of the secondary battery. The storage unit
Discharge information associating a charge state and temperature in a state where the secondary battery is discharged with an internal resistance value of the secondary battery,
Preliminarily storing charging information that associates the charging state and temperature in a state where the secondary battery is charged with the internal resistance value of the secondary battery,
The magnification calculator
When the resistance value is calculated by the individual resistance calculation unit based on the current detected by the current detection unit and the voltage detected by the voltage detection unit during a period when the secondary battery is discharged, The magnification calculator calculates the magnification as a discharge magnification,
When the resistance value is calculated by the individual resistance calculator based on the current detected by the current detector and the voltage detected by the voltage detector during the period when the secondary battery is charged, The magnification calculation unit calculates the magnification as a charging magnification,
The internal resistance value acquisition unit
When acquiring the internal resistance value of the secondary battery during the period when the secondary battery is discharging, the charge state and the temperature are associated with each other by the discharge information stored in the storage unit. A multiplication value obtained by multiplying the internal resistance value by the magnification is obtained as the internal resistance value of the secondary battery,
When acquiring the internal resistance value of the secondary battery during the period when the secondary battery is charged, it is associated with the state of charge and the temperature by the charging information stored in the storage unit. The internal resistance detection circuit according to claim 1, wherein a multiplication value obtained by multiplying the internal resistance value by the magnification is acquired as an internal resistance value of the secondary battery. A plurality of the secondary batteries are connected in parallel to form a battery module,
The current detection unit detects an overall current that is a current flowing through the battery module,
The voltage detection unit detects an overall voltage that is a voltage between both ends of the battery module,
The internal resistance detection circuit is
A resistance calculation unit for calculating a resistance value of the battery module based on the total current and the total voltage;
At least one or more switching elements connected in series with respect to the number of secondary batteries that is one less than the number of secondary batteries included in the battery module among the plurality of secondary batteries,
Between each of the series circuits configured by connecting the secondary battery and the switching element in series, or between the secondary battery not connected to the switching element and each of the series circuits, connected in parallel And further comprising a connection part constituting the battery module including the plurality of secondary batteries and the one or more switching elements,
The individual resistance calculator is
The internal resistance value of at least one of the plurality of secondary batteries is calculated based on a resistance value calculated by the resistance calculation unit in a setting state in which the switching element is turned on and off in a predetermined state. The internal resistance detection circuit according to 1 or 2. The individual resistance calculation unit sequentially calculates internal resistance values of the plurality of secondary batteries while changing the on / off state of the switching element in the setting state,
The internal resistance according to claim 3, further comprising an individual current calculation unit that calculates a current flowing through each of the secondary batteries based on the plurality of internal resistance values calculated by the individual resistance calculation unit and the total current. Detection circuit. The said individual electric current calculation part sets the number of the secondary battery contained in the said battery module to n, gives the number of 1-n to each said secondary battery, m number (m is any one among 1-n) No.) for the secondary battery, the internal resistance value calculated by the individual resistance calculator is r (m), the total current is I, and the current flows to the m-th secondary battery using the following formula (A). The internal resistance detection circuit according to claim 4, wherein a current value I (m) of the current is calculated.

The individual resistance calculation unit sequentially calculates the internal resistance values of the plurality of secondary batteries while changing the ON / OFF state of the switching element in the set state, and the plurality of secondary batteries are all connected in parallel. Calculate the resistance value of the battery module in a state of being as an overall resistance value,
Individual current calculation for calculating the current value of the current flowing through each secondary battery based on the ratio between the internal resistance value and the total resistance value calculated by the individual resistance calculation unit and the total current. The internal resistance detection circuit according to claim 3, further comprising a unit. The individual current calculation unit sets the number of secondary batteries included in the battery module to n, assigns numbers 1 to n to the secondary batteries, and the individual resistance calculation unit for the m-th secondary battery. The calculated internal resistance value is r (m), the total resistance value is R _total , the total current is I, and the current value of the current flowing through the m-th secondary battery using the following formula (B) The internal resistance detection circuit according to claim 6, wherein I (m) is calculated.
I (m) = {R _total / r (m)} × I (B) The individual resistance calculation unit sequentially calculates internal resistance values of the plurality of secondary batteries while changing the on / off state of the switching element in the setting state,
The number of secondary batteries included in the battery module is n, each secondary battery is assigned a number from 1 to n, and the internal resistance value calculated by the individual resistance calculation unit for the m-th secondary battery is r (m), and the ratio of the internal resistance values r (1) to r (n) is p (1): p (2):...: p (n), and the mth secondary battery flows. When the upper limit value of the current that can be performed is I _lim (m), an overall limit value calculation unit that calculates an overall limit value I _{lim_total} that is an allowable upper limit value of the overall current using the following formula (C) The internal resistance detection circuit according to claim 3, further comprising:

The individual resistance calculation unit sequentially calculates the internal resistance values of the plurality of secondary batteries while changing the ON / OFF state of the switching element in the set state, and the plurality of secondary batteries are all connected in parallel. Calculate the resistance value of the battery module in a state of being as an overall resistance value,
The number of secondary batteries included in the battery module is n, each secondary battery is assigned a number from 1 to n, and the internal resistance value calculated by the individual resistance calculation unit for the m-th secondary battery is r (m), the total resistance value is _Rtotal , the ratio between _Rtotal and r (m) is _Ptotal : P (m), and the upper limit value of the current that the mth secondary battery can flow is 4 further includes an overall limit value calculation unit that calculates an overall limit value I _{lim_total} , which is an allowable upper limit value of the overall current, using the following equation (D) when I _lim (m): 8. The internal resistance detection circuit according to any one of 7 above.

  The individual resistance calculator is an on / off state of a switching element connected to a target secondary battery, which is a secondary battery to be detected, of which the internal resistance value is to be detected among the plurality of secondary batteries, Based on the resistance value calculated by the resistance calculation unit in a setting state in which one or a plurality of switching elements connected to a secondary battery other than the target secondary battery are different from each other, the target second battery The internal resistance detection circuit according to claim 3, wherein the internal resistance value of the secondary battery is calculated. A plurality of the switching elements are provided,
The plurality of switching elements are respectively connected in series with all of the plurality of secondary batteries,
The connection unit connects all the series circuits in parallel,
The individual resistance calculation unit is configured to turn on a switching element connected to the target secondary battery and turn off a switching element connected to a secondary battery other than the target secondary battery. The internal resistance detection circuit according to claim 10, wherein the resistance value calculated by the step is acquired as an internal resistance value of the target secondary battery. The switching elements are respectively connected in series to the remaining secondary batteries excluding one of the plurality of secondary batteries,
The connection unit connects in parallel all the series circuits and the basic secondary battery which is the one secondary battery,
The individual resistance calculation unit acquires a resistance value calculated by the resistance calculation unit in a setting state in which all the switching elements are turned off as an internal resistance value of the basic secondary battery, and connects to the target secondary battery The resistance value calculated by the resistance calculation unit in a setting state in which the switching element turned on and the switching element connected to a secondary battery other than the target secondary battery is turned off is acquired as a partial resistance value, The internal resistance detection circuit according to claim 10, wherein an internal resistance value of the target secondary battery is calculated based on an internal resistance value of the basic secondary battery and the partial resistance value. The said individual resistance calculation part calculates the internal resistance value r of the said object secondary battery based on following formula (E), when re is the internal resistance value of the said basic secondary battery, and the said partial resistance value is Rb. Item 13. An internal resistance detection circuit according to Item 12.
r = (re × Rb) / (re−Rb) (E) A plurality of the switching elements are provided,
The plurality of switching elements are respectively connected in series with all of the plurality of secondary batteries,
The connection unit connects all the series circuits in parallel,
The individual resistance calculation unit acquires, as an overall resistance value, a resistance value calculated by the resistance calculation unit in a setting state in which all the switching elements are turned on, and turns off the switching elements connected to the target secondary battery. And a resistance value calculated by the resistance calculation unit in a set state in which a switching element connected to a secondary battery other than the target secondary battery is turned on is acquired as a partial resistance value, and the total resistance value and the The internal resistance detection circuit according to claim 10, wherein an internal resistance value of the target secondary battery is calculated based on a partial resistance value. The switching elements are respectively connected in series to the remaining secondary batteries excluding one of the plurality of secondary batteries,
The connection unit connects in parallel all the series circuits and the basic secondary battery which is the one secondary battery,
The individual resistance calculation unit acquires, as the total resistance value, a resistance value calculated by the resistance calculation unit using the total current and the total voltage in a setting state in which all the switching elements are turned on. The resistance using the total current and the total voltage in a setting state in which a switching element connected to a secondary battery is turned off and a switching element connected to a secondary battery other than the target secondary battery is turned on The internal resistance detection according to claim 10, wherein the resistance value calculated by the calculation unit is acquired as a partial resistance value, and an internal resistance value of the target secondary battery is calculated based on the total resistance value and the partial resistance value. circuit. The individual resistance calculation unit calculates internal resistance values r of all the remaining secondary batteries by sequentially setting the remaining secondary batteries as the target secondary battery, and calculates the residual resistance of all the remaining secondary batteries. Based on the internal resistance value r, a combined resistance value obtained by connecting all the remaining secondary batteries in parallel is calculated as Rc, and the total resistance value is _Rtotal. The internal resistance detection circuit according to claim 15, wherein the internal resistance value re of the secondary battery is calculated.
re = (Rc × R _total ) / (Rc−R _total ) (F) The said individual resistance calculation part calculates the internal resistance value r of the said object secondary battery based on following formula (G), when the said total resistance value is _Rtotal and the said partial resistance value is Rb. The internal resistance detection circuit according to any one of the above.
r = (Rb × R _total ) / (Rb−R _total ) (G) A plurality of the switching elements are provided,
The plurality of switching elements are respectively connected in series with all of the plurality of secondary batteries,
The connection unit connects all the series circuits in parallel,
The individual resistance calculation unit is a secondary battery in which a resistance value calculated by the resistance calculation unit in a set state in which one of the plurality of switching elements is turned on is connected in series with the turned on switching element. After being acquired as the internal resistance value, the remaining switching elements other than the turned-on switching elements are set in a sequentially turned on state, and the resistance value calculated by the resistance calculation unit immediately before the sequential turning on each time the sequential switching elements are turned on. Are connected in series with the sequentially turned on switching elements based on the first partial resistance value and the second partial resistance value which is the resistance value calculated by the resistance calculation unit in the sequentially turned on state. The internal resistance detection circuit of any one of Claims 3-9 which calculates the internal resistance value of the object secondary battery which is a secondary battery. The switching elements are respectively connected in series to the remaining secondary batteries excluding one of the plurality of secondary batteries,
The connection unit connects in parallel all the series circuits and the basic secondary battery which is the one secondary battery,
The individual resistance calculation unit sequentially acquires the resistance value calculated by the resistance calculation unit as an internal resistance value of the basic secondary battery in a setting state in which all the switching elements are turned off, and then sequentially turns on the switching elements. The first partial resistance value, which is the resistance value calculated by the resistance calculation unit immediately before the sequential turn-on, and the resistance calculation unit in the sequentially turned-on state each time the sequential turn-on is performed. 10. The internal resistance value of the target secondary battery, which is a secondary battery connected in series with the sequentially turned on switching elements, is calculated based on the second partial resistance value that is a resistance value. The internal resistance detection circuit according to any one of claims. A plurality of the switching elements are provided,
The plurality of switching elements are respectively connected in series with all of the plurality of secondary batteries,
The connection unit connects all the series circuits in parallel,
The individual resistance calculator is configured to sequentially turn off the plurality of switching elements one by one after calculating the resistance value by the resistance calculator in a setting state where the plurality of switching elements are turned on, and sequentially A first partial resistance value that is a resistance value calculated by the resistance calculation unit in the sequentially turned off state each time the switch is turned off, and a second resistance value that is calculated by the resistance calculation unit immediately before the turn-off. The internal resistance value of the target secondary battery, which is a secondary battery connected in series with the sequentially turned off switching elements, is calculated based on the partial resistance value. Internal resistance detection circuit. The switching elements are respectively connected in series to the remaining secondary batteries excluding one of the plurality of secondary batteries,
The connection unit connects in parallel all the series circuits and the basic secondary battery which is the one secondary battery,
The individual resistance calculation unit is configured to sequentially turn off the plurality of switching elements one by one after calculating the resistance value by the resistance calculation unit in a setting state where all the switching elements are turned on. A first partial resistance value that is a resistance value calculated by the resistance calculation unit in the sequentially turned off state each time the switch is turned off, and a second resistance value that is calculated by the resistance calculation unit immediately before the turn-off. The internal resistance value of the target secondary battery, which is a secondary battery connected in series with the sequentially turned off switching elements, is calculated based on the partial resistance value. Internal resistance detection circuit. The individual resistance calculation unit calculates an internal resistance value r of the target secondary battery based on the following formula (H) when the first partial resistance value is Rs and the second partial resistance value is Rp. Item 22. The internal resistance detection circuit according to any one of Items 18 to 21.
r = (Rs × Rp) / (Rs−Rp) (H) The resistance calculator is
The current detection unit and the voltage detection unit obtain a plurality of sets of the total current and the total voltage detected at synchronized timing, and the slopes of the regression lines obtained from the plurality of sets are obtained from the battery module. The internal resistance detection circuit according to claim 3, wherein the internal resistance detection circuit is calculated as a resistance value. A discharge controller for controlling current supply from the battery module to the load;
The resistance calculation unit is based on the change amount of the overall voltage and the change amount of the overall current generated in synchronization with the change of the current supply amount when the discharge control unit changes the current supply amount. The internal resistance detection circuit according to any one of claims 3 to 23, wherein a resistance value of the battery module is calculated. An upper limit value of a current that can be passed through one secondary battery among the plurality of secondary batteries is preset,
A switching unit for opening and closing a current supply path from the battery module to the load;
A current limiting unit connected in parallel with the switching unit, and capable of switching between a blocking state of blocking current and a limiting state of limiting current flowing in a range not exceeding the upper limit;
A discharge control unit that starts current supply to the load by switching the current limiting unit from the interrupted state to the limited state in the set state;
The resistance calculation unit is based on the change amount of the total voltage and the change amount of the total current generated in synchronization with the change of the current supply amount when the discharge control unit starts the current supply. Calculating a resistance value of the battery module;
The individual resistance calculation unit ends the setting state by turning on the plurality of switching elements after the resistance value is calculated by the resistance calculation unit in the setting state.
The internal resistance detection circuit according to any one of claims 11 to 13, wherein the discharge control unit causes the switching unit to close the current supply path after the plurality of switching elements are turned on. An upper limit value of a current that can be passed through one secondary battery among the plurality of secondary batteries is preset,
A switching unit for opening and closing a current supply path from the battery module to the load;
The current flowing in a range that does not exceed the multiplication value of the cut-off state that is connected in parallel with the switching unit and cuts off the current and that is one less than the number of secondary batteries included in the battery module and the upper limit value is limited. A current limiter that is switchable to a limited state;
A discharge control unit that starts current supply to the load by switching the current limiting unit from the interrupted state to the limited state in the set state;
The resistance calculation unit is based on the change amount of the total voltage and the change amount of the total current generated in synchronization with the change of the current supply amount when the discharge control unit starts the current supply. Calculating a resistance value of the battery module;
The individual resistance calculation unit ends the setting state by turning on the plurality of switching elements after the resistance value is calculated by the resistance calculation unit in the setting state.
The internal resistance detection circuit according to any one of claims 14 to 17, wherein the discharge control unit causes the switching unit to close the current supply path after the plurality of switching elements are turned on. A charging upper limit value that is an upper limit value of the charging current of one secondary battery in the plurality of secondary batteries is preset,
A charge control unit for controlling a charging current for charging the battery module;
The charging control unit changes the charging current in a range not exceeding the charging upper limit value in the setting state,
The resistance calculation unit calculates a resistance value of the battery module based on a change amount of the whole voltage and a change amount of the whole current generated in synchronization with the change of the charging current in the set state,
The individual resistance calculation unit ends the setting state by turning on the plurality of switching elements after the resistance value is calculated by the resistance calculation unit in the setting state.
The internal resistance detection circuit according to claim 11, wherein the charge control unit increases the charge current beyond the upper limit value after the plurality of switching elements are turned on. A charging upper limit value that is an upper limit value of the charging current of one secondary battery in the plurality of secondary batteries is preset,
A charge control unit for controlling a charging current for charging the battery module;
The charge control unit, in the set state, changes the charging current in a range not exceeding a multiplication value of the number less than the number of secondary batteries included in the battery module and the charge upper limit value,
The resistance calculation unit calculates a resistance value of the battery module based on a change amount of the whole voltage and a change amount of the whole current generated in synchronization with the change of the charging current in the set state,
The individual resistance calculation unit ends the setting state by turning on the plurality of switching elements after the resistance value is calculated by the resistance calculation unit in the setting state.
The internal resistance detection circuit according to any one of claims 14 to 17, wherein the charge control unit increases the charge current after the plurality of switching elements are turned on. An internal resistance detection circuit according to any one of claims 1 to 28;
A battery power supply device comprising the secondary battery.

Images