JP2015116051A - Power control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately control load on a battery pack during a fault of a battery cell.SOLUTION: A battery pack 30 includes a plurality of battery cells Cn connected in series; and a plurality of rectifier elements Dn connected to the respective battery cells Cn in parallel. If a fault of any of the battery cells Cn is detected, a maximum output power of the battery pack 30 is determined based on a maximum allowable current of the rectifier elements Dn, and an output from a device operating in response to supply of the electricity from the battery pack 30 is controlled. The maximum output power is determined as a product between the maximum allowable current of the rectifier elements Dn and an output voltage of the battery pack 30 excluding the fault battery cell Cn.

Description

  The present invention relates to a power supply control device that controls an assembled battery including a plurality of battery cells connected in series.

  2. Description of the Related Art Conventionally, a battery pack configured to connect a plurality of battery cells in series and obtain a high voltage is mounted on an electric vehicle that travels using electric power. Here, when some of the battery cells in the assembled battery break down, the current flow path of the entire assembled battery is interrupted, and the electric vehicle may not be able to travel. In order to avoid this, by connecting a rectifying element (diode, more specifically, a Schottky barrier diode, etc.) in parallel to each battery cell, by diverting the current to the rectifying element side in the event of a battery cell failure, Limited movement behavior (limp home) is possible (see, for example, Patent Document 1 below).

JP2013-162597A

  However, while the above-described prior art is intended for a battery having a low voltage such as for a cellular phone, the battery mounted on the electric vehicle is a high voltage battery such as 300V. For this reason, it is difficult to apply the above-described conventional technology as it is to a battery mounted on an electric vehicle. In particular, when a battery cell fails and travels in limp home mode, if the same load is applied to the battery pack during normal operation (non-failure), the rectifier may be damaged and the battery pack may not be usable. is there. In this case, it becomes difficult to move the electric vehicle to a safe position (for example, a repair shop).

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a power supply control device that appropriately controls a load on a battery pack when a battery cell fails.

In order to solve the above-described problems and achieve the object, a power supply control device according to the invention of claim 1 includes a plurality of battery cells connected in series and a plurality of rectifier elements connected in parallel to each of the battery cells. A battery control device for controlling a battery pack comprising: a failure detection means for detecting a failure of the battery cell; and when the failure detection means detects a failure of any of the battery cells, Maximum output determining means for determining the maximum output power of the assembled battery based on the maximum allowable current of the rectifier element, and supply of power from the assembled battery based on the maximum output power determined by the maximum output determining means. And device output control means for controlling the output of the device that operates.
The power supply control device according to claim 2 is characterized in that the maximum output determining means calculates a product of the maximum allowable current of the rectifying element and the output voltage of the assembled battery excluding the failed battery cell as the maximum output power. It is determined that.
According to a third aspect of the present invention, there is provided the power supply control device, wherein the assembled battery is mounted on an electric vehicle that runs by driving a motor using electric power. The motor output control means includes a limit calculated by multiplying a value obtained by dividing the maximum output power by the number of rotations of the motor and a coefficient for converting power supplied to the motor into output torque of the motor. The smaller one of the output torque and the required torque from the driver of the electric vehicle is used as the output torque of the motor.
According to a fourth aspect of the present invention, there is provided the power supply control device, wherein the device that operates by receiving power supply from the assembled battery further includes an air conditioner in the electric vehicle, and the device output control means controls the output torque of the motor. Power supplied to the air conditioner is a value obtained by subtracting a value obtained by multiplying a coefficient for converting the output torque of the motor into power supplied to the motor, the rotational speed of the motor, and an efficiency coefficient of the motor from the maximum output power. It is characterized by that.
According to a fifth aspect of the present invention, there is provided the power supply control device according to the fifth aspect, wherein the electric vehicle includes a charging mechanism that supplies power to the assembled battery, and the power supply control device is configured so that any failure of the battery cell is detected by the failure detection unit. It further comprises charge prohibiting means for prohibiting power supply from the charging mechanism to the assembled battery when detected.

According to the first aspect of the present invention, the maximum output power of the assembled battery is determined based on the maximum allowable current of the rectifying element when a cell battery in the assembled battery fails, and the device that operates by receiving the supply of power from the assembled battery. Since the output is controlled, it is possible to prevent the rectifying element from being damaged by the application of a high voltage, and to continue the operation of the device more reliably.
According to the invention of claim 2, since the product of the maximum allowable current of the rectifying element and the output voltage of the assembled battery is set as the maximum output power, the maximum output allowed at the time of failure can be obtained.
According to the invention of claim 3, since the output torque of the motor of the electric vehicle is either the torque that can be output using all of the maximum output power or the torque requested by the driver of the electric vehicle, The electric vehicle can be moved quickly and reliably.
According to the invention of claim 4, the power supplied to the air conditioner is the power obtained by subtracting the power supplied to the motor from the maximum output power. If possible, the air conditioner can be operated.
According to the invention of claim 5, charging of the assembled battery at the time of failure of the battery cell can be avoided, and safety at the time of failure can be improved.

It is explanatory drawing which shows the structure of the electric vehicle 20 by which the power supply control apparatus 10 concerning embodiment is mounted. 2 is an explanatory diagram showing a functional configuration of a power supply control device 10. FIG. It is a flowchart which shows an example of the failure detection method of the battery cell Cn. It is a flowchart which shows an example of the failure detection method of the battery cell Cn. It is a flowchart which shows an example of the failure detection method of the battery cell Cn. 4 is a flowchart showing processing of the power supply control device 10. It is explanatory drawing which shows the other structure of the electric vehicle 20 by which the power supply control apparatus 10 is mounted.

  Exemplary embodiments of a power supply control device according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment)
FIG. 1 is an explanatory diagram illustrating a configuration of an electric vehicle 20 on which a power supply control device 10 according to an embodiment is mounted.
The power supply control device 10 controls the assembled battery 30 mounted on the electric vehicle 20 that travels by driving the motor 202 using electric power. The assembled battery 30 is used as a traveling battery that stores electric power for traveling of the electric vehicle 20.
Specifically, the power supply control device 10 includes a BMU (Battery Management Unit) 102 that controls the assembled battery 30 and an EV-ECU (Electronic Control Unit) 104 that controls the entire electric vehicle 20. The BMU 102 and EV-ECU 104 include a CPU, a ROM that stores and stores a control program, a RAM as an operation area of the control program, an EEPROM that stores various data in a rewritable manner, an interface unit that interfaces with peripheral circuits, and the like. Consists of including.

  The assembled battery 30 includes a plurality of battery cells Cn (n = 1 to m) connected in series and a plurality of rectifying elements Dn (n = 1 to m) connected in parallel to the respective battery cells Cn. . That is, each battery cell Cn is connected in parallel with a rectifying element such as a diode that is used as a current bypass in the event of a failure. During normal times (when no failure occurs), current wraparound is suppressed by the diode, so that current flows on the battery cell Cn side. When one of the battery cells Cn fails, the resistance of the battery cell Cn increases, so that the resistance value of the rectifying element Dn provided in parallel becomes lower, and the current flows on the rectifying element Dn side.

  As shown in FIG. 7, when any one of the battery cells Cn fails, switching means Sn (n = 1 to m) is provided for switching the current flow path from the failed battery cell Cn to the rectifying element Dn. Also good. In this case, the switching means Sn is turned off during normal times (when no failure occurs), and current flows on the battery cell Cn side. When a failure of any battery cell Cn is detected, the switching means Sn provided in parallel with the battery cell Cn is turned on, and the current flows on the rectifying element Dn side. In FIG. 7, the configuration other than the switching means Sn is the same as that in FIG. 1, and a detailed description thereof will be omitted.

Returning to the description of FIG. 1, each battery cell Cn is provided with a voltmeter 1022 and a thermometer 1024, and the cell voltage VCn and the cell temperature TCn of each battery cell Cn are measured. Note that the voltmeter 1022 and the thermometer 1024 may be provided for each cell unit including a predetermined unit number of battery cells Cn. The measured values of the voltmeter 1022 and the thermometer 1024 are input to the BMU 102.
In addition, an ammeter 1026 is provided between the assembled battery 30 and a device that operates by receiving power supply from the assembled battery 30 (in this embodiment, the motor 202 and the air conditioner 208), and outputs from the assembled battery 30. Measure the current. The measurement value of the ammeter 1026 is input to the BMU 102.

  The assembled battery 30 is charged by receiving an external power supply from a charging connector 220 provided on the vehicle body of the electric vehicle 20. More specifically, a power supply connector (not shown) of a charging device that supplies an external power supply is connected to the charging connector 220, and charging is performed until the assembled battery 30 reaches a fully charged state (or an arbitrary charge amount). At this time, the on-board charger 222 converts the external power source from AC to DC. Note that the on-vehicle charger 222 may not be provided when the external power supply is supplied with direct current.

The motor 202 generates torque (torque) using the electric power stored in the assembled battery 30 and rotates the tire of the electric vehicle 20. The output torque of the motor 202 is controlled based on the operation of the accelerator pedal 204, the brake pedal 206, the shift lever (not shown) or the like by the driver of the electric vehicle 20 and the vehicle speed measured by the vehicle speed sensor 210. The EV-ECU 104 controls the output torque of the motor 202. More specifically, the operation state of the accelerator pedal 204 and the brake pedal 206 and the measured value of the vehicle speed sensor 210 are input to the EV-ECU 104, and the EV-ECU 104 calculates the driver's required torque TD based on the operation state. A control signal for controlling the motor 202 is output.
The motor 202 is provided with an inverter (not shown), and the electric power supplied from the assembled battery 30 is converted from direct current to alternating current.
In addition, the motor 202 generates power using regenerative power by deceleration and supplies power to the assembled battery 30. That is, the motor 202 has a function of a charger that charges the assembled battery 30 during regeneration.

  The air conditioner 208 performs air conditioning in the electric vehicle 20. The air conditioner 208 also operates using the electric power stored in the assembled battery 30. The air conditioner 208 operates so that the air in the vehicle becomes a set temperature or the like based on settings in an air conditioning adjustment unit (such as an operation button or a dial) provided in the vehicle. The operating state of the air conditioner 208 is controlled by the EV-ECU 104. More specifically, an operation state for the air conditioning adjustment unit is input to the EV-ECU 104, and the EV-ECU 104 outputs a control signal for controlling the air conditioner 208 based on the operation state.

  When the battery cell Cn fails, the monitor 212 notifies that fact, and notifies the driver that the electric vehicle 20 is in the limp mode with visual information such as characters and icons. The monitor 212 is provided at a position where the driver can easily see, for example, near the dashboard. When the battery cell Cn has not failed, the monitor 212 may be informed that the battery cell Cn is normal, or may be notified only when there is a failure without notifying. Further, instead of the monitor 212 or together with the monitor 212, a speaker for performing similar notification by voice may be provided.

FIG. 2 is an explanatory diagram showing a functional configuration of the power supply control device 10.
The following functional units are realized by executing the control program by the CPU of the BMU 102 and the EV-ECU 104.
In the present embodiment, each functional unit is separately provided in BMU 102 and EV-ECU 104. However, each functional unit may be provided in either BMU 102 or EV-ECU 104, and BMU 102 or EV. -Each functional unit may be provided in any of the ECUs 104 (or a processing unit having other functions).

Functionally, the power supply control device 10 includes a failure detection unit 102, a maximum output determination unit 104, a device output control unit 106, and a charge prohibition unit 108.
The failure detection means 102 is provided in the BMU 102 and detects a failure of the battery cell Cn.
The failure detection of the battery cell Cn can use various methods of the prior art. Specifically, for example, the failure detection unit 102 measures the cell voltage of each battery cell Cn, and detects that the battery cell has failed when the cell voltage becomes less than a predetermined voltage.
FIG. 3 is a flowchart showing an example of a failure detection method for the battery cell Cn.
In the flowchart of FIG. 3, the failure detection unit 102 obtains the measured value of the voltmeter 1022 provided in each battery cell Cn, less than the threshold voltage V _F of the determination cell voltage V _Cn of any battery cell Cn failure Is determined (step S300). When the cell voltage V _Cn is not less than the threshold voltage V _F (step S300: No), it is assumed that each battery cell Cn is normal (step S302), and the process according to this flowchart ends.
On the other hand, if the cell voltage V _Cn is less than the failure determination threshold voltage VF (step S300: Yes), it is determined that the battery cell Cn has failed (step S304), and a current limit request for the battery cell Cn is made. Is performed (step S306). Specifically, since the internal resistance of the battery cell Cn is increased and finally insulated, a current flows through the rectifier element Dn provided in parallel with the battery cell Cn.
In the case of the configuration of FIG. 7, the switching means Sn provided in parallel with the battery cell Cn is turned on so that a current flows through the rectifying element Dn side.
As a result, the failed battery cell Cn is disconnected from the power supply circuit, the cell voltage V _Cn becomes 0 V (step S308), and the processing according to this flowchart ends.

Moreover, the failure detection means 102 may measure the cell temperature of each battery cell Cn, and may detect that the battery cell Cn has failed when the cell temperature becomes equal to or higher than a predetermined temperature.
FIG. 4 is a flowchart illustrating an example of a failure detection method for the battery cell Cn.
In the flowchart of FIG. 4, the failure detection unit 102 obtains the measured value of the thermometer 1024 provided in each battery cell Cn, the threshold temperature T _F of the cell temperature T _Cn of any battery cell Cn failure determination It is determined whether or not it exceeds (step S400). When the cell temperature _TCn does not exceed the threshold temperature _TF (step S400: No), it is assumed that each battery cell Cn is normal (step S402), and the process according to this flowchart is terminated.
On the other hand, when the cell temperature _TCn exceeds the failure determination threshold temperature _TF (step S400: Yes), it is determined that the battery cell Cn has failed (step S404), and the battery cell Cn A current limit request is made (step S406). Specifically, since the internal resistance of the battery cell Cn is increased and finally insulated, a current flows through the rectifier element Dn provided in parallel with the battery cell Cn.
In the case of the configuration of FIG. 7, the switching means Sn provided in parallel with the battery cell Cn is turned on so that a current flows through the rectifying element Dn side.
As a result, the failed battery cell Cn is disconnected from the power supply circuit, the cell voltage V _Cn becomes 0 V (step S408), and the processing according to this flowchart ends.

Further, the failure detection means 102 uses the cell voltage of each battery cell Cn when the output current of the assembled battery 30 is less than the first predetermined current as a reference voltage, and the output current of the assembled battery 30 is larger than the first predetermined current. When the cell voltage of each battery cell Cn when the second predetermined current is exceeded is used as a comparison voltage, and there is a battery cell Cn whose difference between the comparison voltage and the reference current is equal to or less than the predetermined voltage, the battery cell Cn is out of order. May be detected.
FIG. 5 is a flowchart illustrating an example of a failure detection method for the battery cell Cn.
In the flowchart of FIG. 5, the failure detection unit 102 acquires the output current I _B of the assembled battery 30 from the ammeter 1026, and whether or not the absolute value | I _B | of the output current is less than the first predetermined current I _L. Is determined (step S500). The absolute value of the output current | _{I B} | the first is less than the predetermined current _{I L} (step S500: Yes), the recording (step S502 the cell voltage _{V Cn} of each battery cell Cn at that time as the reference voltage _{V Mn} ) Assuming that each battery cell Cn is normal (step S508), the processing according to this flowchart is terminated.
On the other hand, when the absolute value | I _B | of the output current is not less than the first predetermined current I _L (step S500: No), the absolute value | I _B | of the output current is larger than the first predetermined current I _L. It is determined whether or not the predetermined current _IH is exceeded (step S504). When the absolute value | I _B | of the output current does not exceed the second predetermined current I _H (step S504: No), it is assumed that each battery cell Cn is normal (step S508), and the processing according to this flowchart is performed. finish.
On the other hand, when the absolute value | I _B | of the output current exceeds the second predetermined current IH (step S504: Yes), the cell voltage V _Cn of each battery cell Cn at that time is used as the comparison voltage, and the comparison voltage V difference between _Cn and the reference voltage _{V Mn} determines whether less than the failure determination voltage difference _{V DF} (step S506), when the difference between the comparison voltage _{V Cn} and the reference voltage _{V Mn} is lower than the failure determination voltage difference _{V DF} (Step S506), since the state of the battery cell Cn does not change between when a high current is applied and when a low voltage is applied, it is determined that the battery cell Cn is out of order (Step S510). A current limit request for Cn is made (step S512). Specifically, since the internal resistance of the battery cell Cn is increased and finally insulated, a current flows through the rectifier element Dn provided in parallel with the battery cell Cn.
In the case of the configuration as shown in FIG. 7, the switching means Sn provided in parallel with the battery cell Cn is turned on so that the current flows through the rectifying element Dn side.
As a result, the failed battery cell Cn is disconnected from the power supply circuit, the cell voltage V _Cn becomes 0 V (step S514), and the processing according to this flowchart is terminated.
On the other hand, when the difference between the comparison voltage V _Cn and the reference voltage V _Mn is greater than or equal to the failure determination voltage difference V _DF (step S506), it is assumed that each battery cell Cn is normal (step S508), and the processing according to this flowchart is performed. finish.

Returning to the description of FIG. 2, the maximum output determination unit 104 determines whether the battery pack 30 has the maximum allowable current I _BFH based on the maximum allowable current I _BFH when any failure of the battery cell Cn is detected by the failure detection unit 102. The maximum output power P _BMX is determined. More specifically, the maximum output determining means 104 determines the product of the maximum allowable current I _BFH of the rectifying element Dn and the output voltage V _B of the assembled battery 30 excluding the failed battery cell Cn as the maximum output power P _BMX. To do. That is, the maximum output determination means 104 sets the maximum output power P _BMX of the assembled battery 30 to the following formula (1). Thereby, damage of the rectifier element Dn can be prevented, and an appropriate output power obtained by subtracting the output of the failed battery cell Cn can be set.
P _BMX = I _BFH × V _B (1)

The device output control unit 106 controls the output of a device that operates by receiving power supply from the assembled battery 30 based on the maximum output power P _BMX determined by the maximum output determination unit 104. In the present embodiment, the devices that operate by receiving power supplied from the assembled battery 30 are the motor 202 and the air conditioner 208.
Equipment output control means 108 limits an output torque calculated by multiplying the coefficient K _TP for converting the maximum output power P _BMX to a value obtained by dividing the rotational speed N _M of the motor 202 to supply power to the motor 202 to the output torque of the motor When, among the required torque T _D from the driver of the electric vehicle 20, to a smaller output torque T _M of the motor. That is, device output control means 108, the output torque _{T M} of the motor 202 following equation (2).
T _M = Min (T _D , (P _BMX / N _M ) × K _TP ) (2)

That is, in the case of less than the maximum torque required torque _{T D} to the motor 202 can be output at the maximum output power _{P BMX} is it possible to output the required torque _{T D,} the required torque _{T D} is the maximum output power _{P BMX} to the motor 202 in the maximum torque and the output torque T _M in the case of exceeding the maximum torque that can be output.

Further, the device output control means 108 converts the output torque T _M of the motor 202 into a coefficient K _PT for converting the output torque of the motor 202 into power supplied to the motor 202, the rotation speed N _M of the motor 202, A value obtained by multiplying the efficiency coefficient K _MEF by the maximum output power P _{BMX is} set as the supply power to the air conditioner 208. That is, the device output control means 108 sets the power supply _PAH supplied to the air conditioner 208 to the following formula (3).
_{P AH = P BMX -T M ×} N M × K PT × K MEF ··· (3)

That is, the remainder obtained by subtracting the power supplied to the motor 202 from the maximum output power P _BMX is used as a supply electrode to the air conditioner 208. Note that when the power supplied to the motor 202 is at the maximum output power P _BMX (if required torque T _D is greater than the maximum torque that can be output with the maximum output power P _BMX), can not supply power to the air conditioner 208, The air conditioner 208 stops. Further, when the electric power supplied to the motor 202 is small, such as when the electric vehicle 20 is stopped, the electric power supplied to the air conditioner 208 is increased, and the effectiveness of the air conditioner 208 is increased.

  The charging prohibition unit 108 prohibits the supply of power from the charging mechanism to the assembled battery 30 when the failure detection unit 102 detects a failure of any battery cell Cn. In the present embodiment, the charging mechanism that supplies power to the assembled battery is the in-vehicle charger 222 and the motor 202 during regeneration. For example, the charging prohibition unit 108 outputs a control signal for prohibiting charging of the assembled battery 30 to the in-vehicle charger 222. Further, for example, the charging connector 220 may be locked to prohibit the connection of the power feeding connector. Further, the charging prohibition unit 108 outputs a control signal for prohibiting the power generation operation during regeneration to the motor 202.

FIG. 6 is a flowchart showing processing of the power supply control device 10.
In the flowchart of FIG. 6, the power supply control device 10 first determines whether any one of the battery cells Cn of the assembled battery 30 has failed (step S600). The failure detection method for the battery cell Cn is as described with reference to FIGS. When there is no faulty battery cell Cn (step S600: No), the maximum value I _LIMH of the current control value I _LIM output from the assembled battery 30 is set as the maximum output current I _BMX (step S602), and the current value is _displayed on the monitor 212. Is notified that the current mode is the normal mode (step S604).
More specifically, the maximum value I _LIMH of the current control value I _LIM output from the assembled battery 30 is set as the maximum output current I _BMX , and the minimum value I _LIML is _set as the minimum output current I _BMN .

On the other hand, when there is a faulty battery cell Cn (step S600: Yes), the maximum value I _LIMH of the current control value I _LIM output from the assembled battery 30 is set as the maximum allowable current I _BFH of the rectifying element Dn (step S606). ) Notifies the monitor 212 that the current mode is the limp home mode at the time of failure (step S608). Then, charging to the assembled battery 30 (charging using an external power source and charging using power generated during regeneration) is prohibited by the charging prohibiting unit 108 (step S610).
More specifically, the maximum value I _LIMH of the current control value I _LIM output from the assembled battery 30 is set as the maximum allowable current I _BFH of the rectifying element Dn, and the minimum value I _LIML is set as the minimum allowable current I _BFL of the rectifying element Dn, that is, 0A. And

Next, the maximum output determining means 104 determines the maximum output power P _BMX of the assembled battery 30 as the product of the maximum value I _LIMH of the current control value I _LIM and the output voltage V _B of the assembled battery 30, that is, the following equation (4) (Step S612).
P _BMX = I _LIMH × V _B (4)
When the battery cell Cn is out of order, the maximum value I _LIMH of the current control value I _LIM is the maximum allowable current I _BFH of the rectifier element Dn, and the output voltage V _B is the output voltage of the assembled battery 30 excluding the failed battery cell Cn. (See the above formula (1)).

Subsequently, the device output control means 108 determines based on the output torque _{T M} of the motor 202 in the formula (2) (step S614). The device output control means 108, a power supply _{P AH} to the air conditioner 208 is determined based on the equation (3) (step S616). And the apparatus output control means 108 controls each apparatus (the motor 202 and the air conditioner 208) based on the determined output (step S618), and complete | finishes the process by this flowchart.

As described above, the power supply control device 10 according to the embodiment determines the maximum output power of the assembled battery 30 based on the maximum allowable current of the rectifier element Dn when the cell battery Cn in the assembled battery 30 fails. Controlling the output of the equipment (motor 202 and air conditioner 208) that operates by receiving power supply from the battery 30 prevents the rectifier element Dn from being damaged by the application of a high voltage, and continues the operation of the equipment more reliably. Can be made.
Further, since the power supply control device 10 uses the product of the maximum allowable current of the rectifying element Dn and the output voltage of the assembled battery 30 as the maximum output power, it is possible to obtain the maximum output allowed at the time of failure.
Further, the power supply control device 10 sets the output torque of the motor 202 of the electric vehicle 20 as either a torque that can be output using all of the maximum output power or a torque requested by the driver of the electric vehicle 20, and thus the assembled battery 30. Therefore, the electric vehicle 20 can be moved quickly and reliably at the time of failure.
Further, since the power supply control device 10 uses the power supplied to the air conditioner 208 as the power obtained by subtracting the power supplied to the motor 202 from the maximum output power, the power control device 10 gives priority to the travel of the electric vehicle 20 and stops or travels at a low speed. If possible, the air conditioner 208 can be operated.
Moreover, the power supply control apparatus 10 can avoid the charge of the assembled battery 30 at the time of failure of the battery cell Cn, and can improve the safety at the time of a battery failure.

  DESCRIPTION OF SYMBOLS 10 ... Power supply control device, 20 ... Electric vehicle, 30 ... Assembly battery, 102 ... Failure detection means, 104 ... Maximum output determination means, 106 ... Equipment output control means, 108 ... Charge prohibition means, 202 …… Motor, 204 …… Accelerator pedal, 206 …… Brake pedal, 208 …… Air conditioner, 210 …… Vehicle speed sensor, 212 …… Monitor, 220 …… Charging connector, 222 …… In-vehicle charger, 1022 …… Voltage Total: 1024 ... Thermometer, 1026 ... Ammeter, Cn ... Battery cell, Dn ... Rectifier, Sn ... Switching means.

Claims (5)

A power supply control device that controls a battery pack comprising a plurality of battery cells connected in series and a plurality of rectifying elements connected in parallel to each of the battery cells,
A failure detection means for detecting a failure of the battery cell;
A maximum output determining means for determining a maximum output power of the assembled battery based on a maximum allowable current of the rectifying element when a failure of any of the battery cells is detected by the failure detecting means;
On the basis of the maximum output power determined by the maximum output determining means, device output control means for controlling the output of a device that operates by receiving power supply from the assembled battery;
A power supply control device comprising: The maximum output determining means determines a product of a maximum allowable current of the rectifying element and an output voltage of the assembled battery excluding the failed battery cell as the maximum output power.
The power supply control device according to claim 1. The assembled battery is mounted on an electric vehicle that runs by driving a motor using electric power,
A device that operates by receiving power supply from the assembled battery includes the motor,
The device output control means includes a limit output torque calculated by multiplying a value obtained by dividing the maximum output power by the number of rotations of the motor, and a coefficient for converting power supplied to the motor into output torque of the motor; Of the required torque from the driver of the car, the smaller one is the output torque of the motor,
The power supply control device according to claim 2. The device that operates by receiving power supply from the assembled battery further includes an air conditioner in the electric vehicle,
The device output control means is configured to multiply the output torque of the motor by a value obtained by multiplying a coefficient for converting the output torque of the motor into electric power supplied to the motor, a rotational speed of the motor, and an efficiency coefficient of the motor. The value subtracted from the power is the power supplied to the air conditioner,
The power supply control device according to claim 3. The electric vehicle includes a charging mechanism that supplies power to the assembled battery,
The power supply control device further includes charge prohibiting means for prohibiting power supply from the charging mechanism to the assembled battery when a failure of any of the battery cells is detected by the failure detecting means.
The power supply control device according to claim 3 or 4,

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