WO2017170205A1 - Secondary battery degradation assessment device - Google Patents

Abstract

Provided is a secondary battery degradation assessment device that is capable of assessing the degradation of a secondary battery with a relatively high degree of accuracy using a simple configuration and is suitable for evaluating the degradation of an emergency power supply in which a plurality of batteries are connected. This secondary battery degradation assessment device is provided with a voltage measurement unit (21) for measuring the DC voltage between the terminals of the battery (2), a discharge circuit (35) comprising a current limiting resistor (36) and switch (37) connected in parallel with the battery (2), and a degradation assessment unit (13a). A discharge management unit (22) compares the battery DC voltage with a voltage setting value and causes the battery to discharge if the battery DC voltage is higher than the setting value, that is, if the DC voltage is higher than an upper limit value; monitors the DC voltage during the discharging; and stops the discharging if the DC voltage falls below a lower limit value. A degradation range unit (13a) measures the frequency of discharging by the discharge circuit (35) resulting from control by the discharge management unit (22) and assesses the degradation of the battery (2) according to the discharge frequency. The frequency can be made to be, for example, the number of discharges within a set period of time or the discharge time between the current discharge and the preceding discharge.

Description

Secondary battery deterioration judgment device Related applications

This application claims the priority of Japanese Patent Application No. 2016-063179 filed on Mar. 28, 2016 and the priority of Japanese Patent Application No. 2016-183589 filed on Sep. 21, 2016. Cited as part of this application.

The present invention is used in a data center, a mobile phone base station, or any other emergency power source that requires stable power supply, or a general power source in which a plurality of batteries are connected in series. The present invention relates to a secondary battery deterioration determination device.

In data centers and mobile phone base stations, it is important to provide a stable power supply, and an AC commercial power supply is used in steady state, but a secondary battery is used as an uninterruptible power supply when the AC commercial power supply stops. Power supply is equipped. The charging method for the emergency power supply includes trickle charging, which uses a charging circuit to charge with a small amount of current in a steady state, and a load and a secondary battery connected in parallel to the rectifier, applying a constant current to the load. There is a form of float charging that charges while driving. In general, many types of trickle charging are employed for emergency power supplies.

The emergency power supply requires a voltage and current that can drive a load driven by a commercial power supply. The voltage of one secondary battery (battery) is low and the capacity is small, so multiple batteries are connected in series. A plurality of battery groups are connected in parallel. Each battery is a lead acid battery or a lithium ion battery.

In such an emergency power source, since the voltage of the battery decreases due to deterioration, it is desirable to determine the deterioration of the battery and replace the deteriorated battery in order to ensure reliability. However, an apparatus that can accurately determine the deterioration of a large number of batteries in a large-scale emergency power source such as a data center or a mobile phone base station has not been proposed.

As a proposal example of conventional battery deterioration determination, as an in-vehicle battery checker, a proposal for measuring the whole battery collectively (for example, Patent Document 1), applying a pulsed voltage to the battery, and determining the battery from the input voltage and the response voltage Proposals for calculating the overall internal impedance (for example, Patent Document 2), methods for determining deterioration by measuring the internal resistance of individual cells connected in series in the battery (for example, Patent Document 3), and the like have been proposed. The AC four-terminal method is used to measure the internal resistance of each cell. Further, an AC four-terminal battery tester has been commercialized as a handy checker that measures a very small resistance value such as the internal resistance of the battery (for example, Non-Patent Document 1).

In Patent Documents 1 and 2, wireless data transmission is also proposed, cable management and manual work reduction, and computer data management are also proposed.

JP-A-10-170615 Japanese Patent Laid-Open No. 2005-1000096 JP 2010-164441 A

AC 4-terminal method battery tester internal resistance measuring instrument IW7807-BP (Rev. 1.7.1, February 16, 2015, Tokyo Devices) (https://tokyodevices.jp/system/attachments/files/000/000/298 /original/IW7807-BP-F_MANUAL.pdf)

All of the conventional secondary battery degradation determination devices calculate the internal resistance by applying a current to the battery and measuring the inter-terminal voltage, so that the sensor configuration is complicated. In particular, since the emergency power supply is composed of a large number of batteries, if the configuration of the sensor for measuring each battery is complicated, the entire apparatus becomes large and the cost increases as a whole of the deterioration determination apparatus. In the conventional handy checker (Non-Patent Document 1), there are too many measurement points and no feasibility in an emergency power source in which tens or hundreds of batteries are connected.

∙ Emergency power supply batteries are mostly used in series, and are always charged by float charging or trickle charging. When the battery deteriorates, the internal resistance increases, and in a battery connected in series, the DC (direct current) voltage between the terminals of the deteriorated battery becomes high. Deterioration can be determined. However, since the fluctuation of the battery DC voltage also occurs due to other factors, it is not possible to accurately determine the deterioration of the battery simply by measuring the voltage between the terminals.

SUMMARY OF THE INVENTION An object of the present invention is to provide a secondary battery deterioration determination device that can determine deterioration of a secondary battery with a certain degree of accuracy with a certain degree of accuracy and is suitable for deterioration determination in an emergency power source to which a large number of batteries are connected. Is to provide.

Hereinafter, in order to facilitate understanding, the present invention will be described with reference to the reference numerals of the embodiments for convenience.

The secondary battery deterioration determination device of the present invention includes a voltage measuring unit 21 that measures a DC voltage between terminals of a battery 2 that is a secondary battery, a current limiting resistor 36 and a switch 37 that are connected in parallel to the battery 2. The battery DC voltage measured by the discharge circuit 35 and the voltage measuring unit 21 is higher than the set upper limit value, the switch 37 is turned on to discharge the battery 2, During this ON, when the battery DC voltage is monitored and falls below a set lower limit, the switch 37 is turned OFF to stop the discharge, and the discharge circuit controlled by the discharge manager 22 Deterioration determination units 19 and 19A that measure the discharge frequency of 35 and determine the deterioration of the battery 2 based on the discharge frequency are provided.
When monitoring the battery DC voltage, the switch 37 may be temporarily turned off to stop discharging.
The “upper limit value” and the “lower limit value” are arbitrarily determined values, for example, preferably set to the upper limit or the lower limit of the range of normal voltage that is a voltage when the battery 2 is not deteriorated. In general, a battery of 2V has a normal voltage range of 1.8 to 2.23V. In addition, in this specification, the description of “when higher than the upper limit” (or “lower than the lower limit”) or the like in terms of the magnitude of the reference value is “more than” (or “less than”), and It may be interpreted as either “excess” (or “below”).

If the individual battery DC voltage is measured, the deterioration of the battery 2 can be determined to some extent. However, since the fluctuation of the battery DC voltage also occurs due to other factors, it is not possible to accurately determine the deterioration of the battery simply by measuring the voltage between the terminals. In the present invention, when the battery DC voltage is measured in a charged state by voltage application or the like, and the battery DC voltage is higher than the upper limit value, energy is consumed by the current limiting resistor 36 by discharging, and the battery DC voltage is lower than the lower limit value. Stop discharging and prevent overcharge. Such an operation is repeated, and the deterioration of the battery 2 is determined based on the discharge frequency. If the discharge frequency is high, it can be determined that the battery has deteriorated. That is, since the internal resistance increases when the battery is deteriorated, the voltage of the deteriorated battery is increased among the plurality of batteries connected in series. When the voltage is high, the discharge frequency increases and it is determined that the battery is deteriorated.

As described above, since the discharge start at the upper limit value of the voltage and the discharge stop at the lower limit value are repeated and the determination is made based on the discharge frequency, the deterioration of the battery can be determined with a certain degree of accuracy. In addition, since no current application means for measurement is required, the structure is simple and can be manufactured at low cost. The “discharge frequency” may be managed by the number of discharges or by a discharge interval.

For example, the deterioration determination unit 13a measures the number of discharges performed within a set time as a process for determining deterioration due to the discharge frequency, and if the number of discharges exceeds the set number of times, the battery has deteriorated. It may be determined. (The example of FIG. 5A and FIG. 5B and the example of FIG. 6 correspond.) When it determines by the frequency | count of discharge in this way, deterioration of a battery can be determined easily.

In addition, the deterioration determination unit 13a measures the discharge interval between the previous discharge and the current discharge as a determination of deterioration due to the discharge frequency, and if the discharge interval is shorter than the set interval, the battery is deteriorated. It may be determined. (The example of FIG. 7 and the example of FIG. 8 correspond.) A short discharge interval means a high discharge frequency. Thus, even if it determines with a discharge interval, deterioration of a battery can be determined easily.

In the present invention, the deterioration determination unit 19 measures a switching time which is a time between the start of the discharge and the stop of the discharge as a determination of the deterioration due to the discharge frequency, and the discharge time which is the switching time. A configuration may be adopted in which it is determined that the battery has deteriorated if it is shorter than the set time. (The example of FIG. 9 and the example of FIG. 10 correspond.) The discharge time which is a switching time also shows the frequency of discharge, and can perform deterioration determination.

In the present invention, as the process for determining the deterioration due to the discharge frequency, the discharge management unit 22 starts discharging in response to the fact that the battery DC voltage is higher than the upper limit value, and then temporarily stops at a predetermined interval. When the switch 37 is turned off and the battery DC voltage measured by the voltage measuring unit 21 becomes lower than the lower limit value, the switch 37 is maintained in the OFF state, and the voltage monitoring, comparison with the upper limit value is performed. When the process of temporarily turning off the switch, comparing with the lower limit value, and maintaining the switch in the OFF state is repeated, the battery deteriorates if the number of discharges within a set time is greater than the set value. If so, the deterioration determining unit 19 may determine. (The example of FIG. 11 is applicable.) As described above, the battery 2 is accurately turned on by measuring the voltage by temporarily turning off the switch while discharging the battery, and comparing the number of discharges within the set time with the set value. Can be determined. The “number of discharges is a set value” is a value arbitrarily set by design.

In the present invention, the deterioration determination device is a device for determining deterioration of the battery of a power source in which a plurality of batteries 2 are connected in series, and for each battery, the voltage measurement unit 21, the discharge circuit 35, and the A discharge management unit 22 is provided, and the deterioration determination units 19 and 19A obtain an average value of measured battery DC voltages after the voltage measurement by all the voltage measurement units 21 of the plurality of batteries is performed. The upper limit value and the lower limit value may be determined based on the average value. The “upper limit value and lower limit value” may be fixed values, but an appropriate battery DC voltage may be slightly different depending on each power source. Therefore, as described above, the average value of the battery DC voltage of all the batteries is obtained, and the upper limit value and the lower limit value of the voltage for discharging and stopping the discharge are determined on the basis of this average value. It is possible to perform a more appropriate discharge and improve the accuracy of deterioration determination. For example, the upper limit value is higher by a value determined from the average value, and the lower limit value is lower by a value determined from the average value.

In the present invention, the current limiting resistor 36 and the switch 37 may be mounted on the same circuit board as the voltage measuring unit 21. By mounting on the same circuit board, the device is simplified and made compact.

In the present invention, the circuit of the current limiting resistor 36 and the switch 37 and the circuit of the voltage measuring unit 21 may share the cable 38 connected to the battery. Both the circuit of the current limiting resistor 36 and the switch 37 and the voltage measuring unit 21 are connected to a battery. Cable wiring is simplified by sharing the connection circuit between them.

The secondary battery deterioration determination device of the present invention is provided with a plurality of voltage sensors 7 each having the voltage measurement unit 21, the discharge circuit 35, and the discharge management unit 22, and one unit for each of the voltage sensors 7. The information processing equipment 11A that collects data by measuring or processing each of the voltage sensors 7 and operating instructions for the voltage sensors 7 may be used. In the case of this configuration, measurement control by a large number of voltage sensors 7 connected to each battery 2 in an emergency power source including tens, hundreds, and a large number of batteries 2, management of measurement results, deterioration determination results, etc. Easy to do.

When the information processing equipment 11A is provided, the information processing equipment 11A may have means for configuring the deterioration determining unit 19 or a part of the deterioration determining unit 19. In order to determine the deterioration of each battery 2, a common process such as an average value calculation may be required, and the common process can be efficiently performed by using an information processing facility 11 </ b> A different from the voltage sensor 7. .

In this invention, when the deterioration determination unit 19 determines that the battery 2 is deteriorated, it has an alarm unit 39 for generating an alarm to be perceived by an operator (or a supervisor), the voltage measurement unit 21, the discharge circuit 35, the The discharge management unit 22, the deterioration determination unit 19, and the alarm unit 39 may be housed in a common housing (not shown). In the case of this configuration, the deterioration of the battery 2 can be determined by a single sensor without providing an information processing facility for collecting data. In addition, a wireless communication unit for communicating with the information processing facility becomes unnecessary.

Any combination of at least two configurations disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the invention.

The present invention will be understood more clearly from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in a plurality of drawings indicate the same or corresponding parts.

It is a block diagram which shows the conceptual structure of the voltage sensor and information processing equipment in the deterioration determination apparatus of the secondary battery which concerns on one Embodiment of this invention. It is explanatory drawing which shows the juxtaposition state of the voltage sensor. It is a circuit diagram which shows the relationship of the emergency power supply provided with the some battery of the determination target of the degradation determination apparatus. It is a flowchart which shows transmission / reception of the signal between the voltage sensor which comprises the degradation determination apparatus, a controller, and a data server. It is a flowchart which shows an example of the deterioration determination process by the deterioration determination apparatus. It is a flowchart which shows an example of the deterioration determination process by the deterioration determination apparatus. It is a flowchart which shows the other example of the deterioration determination process by the deterioration determination apparatus. It is a flowchart which shows the further another example of the degradation determination process by the degradation determination apparatus. It is a flowchart which shows the further another example of the degradation determination process by the degradation determination apparatus. It is a flowchart which shows the further another example of the degradation determination process by the degradation determination apparatus. It is a flowchart which shows the further another example of the degradation determination process by the degradation determination apparatus. It is a flowchart which shows the further another example of the degradation determination process by the degradation determination apparatus. It is a block diagram which shows the conceptual structure of the deterioration determination apparatus of the secondary battery which concerns on other embodiment of this invention.

An embodiment of the present invention will be described with reference to FIGS. 1 to 5B. FIG. 1 is a conceptual diagram of a voltage sensor 7 and an information processing apparatus 11A that constitute a deterioration determination device for a secondary battery. FIG. 3 is an overall conceptual configuration of the deterioration determination device and an emergency power source that includes a battery to be determined. FIG.

In FIG. 3, a power source 1 to be subjected to deterioration determination is an emergency power source in a data center, a mobile phone base station, or any other power supply device that requires stable power supply. The power source 1 has a plurality of battery groups 3 in which a plurality of batteries 2 as secondary batteries are connected in series, and these battery groups 3 are connected in parallel and connected to a load 4. Each battery 2 may be a single cell or a plurality of cells connected in series. In this example, each battery 2 consists of a single cell.

The emergency power source 1 is connected to the positive terminal 5A through the charging circuit 6 and the diode 15 among the positive and negative terminals 5A and 5B of the main power source 5 connected to the positive and negative terminals of the load 4. The negative terminal 5B is directly connected. The diode 15 is connected in parallel with the charging circuit 6 in such a direction that current flows from the emergency power source 1 to the load 4. The main power source 5 is composed of, for example, a DC power source that is connected to an AC commercial power source via a rectifier circuit and a smoothing circuit (both not shown) and converts to DC power.

The positive potential of the emergency power source 1 is lower than the positive potential of the main power source 5 and normally does not flow to the load 4. However, when the main power source 5 stops or the function is lowered, the potential on the main power source 5 side decreases. Then, the electric charge stored in the emergency power supply 1 is fed to the load 4 via the diode 15. In addition, the charge form which connected the charging circuit 6 as mentioned above is called a trickle charge form.

This secondary battery deterioration determination device is a device for determining the deterioration of each battery 2 in the power source 1, and includes a plurality of voltage sensors 7 connected to each battery 2 and one information processing facility 11A. Composed. In this example, the information processing facility 11 </ b> A includes a controller 11 and a data server 13.

The voltage sensor 7 will be described with reference to FIG. Each voltage sensor 7 includes a measurement / control unit 20 and a discharge circuit 35. The measurement / control unit 20 is provided with a voltage measurement unit 21 that measures a DC (direct current) voltage between terminals of the battery 2, an arithmetic control unit 23 including a microcomputer or the like, and a wireless communication unit 24.

The voltage measurement unit 21 is a part of the voltage sensor 7 that is directly related to voltage measurement or a part that is essential for voltage measurement, and is a part excluding an additional configuration related to voltage measurement. The voltage measuring unit 21 is a device generally called a voltage sensor, and the voltage sensor 7 of this embodiment may be called a voltage sensor device or a voltage sensor unit.

The discharge circuit 35 is a series circuit of a current limiting resistor 36 and a switch 37. The current limiting resistor 36 is also referred to as a bleeder resistor. The switch 37 includes a semiconductor switching element such as a transistor. The wireless communication unit 24 is a means for performing wireless communication with the information processing facility 11A, and transmits a measured voltage and the like and receives a command. The wireless communication unit 24 has an antenna 24a.

The arithmetic control unit 23 is provided with an operation control unit 27 and a discharge management deterioration determination unit 18. The operation control unit 27 is a means for controlling the entire measurement / control unit 20 and the wireless communication unit 24 in accordance with a command given from the wireless communication unit 24 and a set sequence program. The control contents of the operation control unit 27 will be described later with reference to the flowchart of FIG.

The discharge management deterioration determination unit 18 includes a discharge management unit 22 that controls the discharge circuit 35 in accordance with the voltage measured by the voltage measurement unit 21. You may have the deterioration determination part 19 which determines deterioration of the battery 2. FIG. When there is the data server 13 (FIG. 3), it centrally manages which voltage sensor 7 outputs a deterioration alarm.

Depending on the system configuration, there may be a case where no data server is provided. In that case, as shown in FIG. 12, a degradation determination unit 19 and an alarm unit 39 may be provided in the voltage sensor 7. The alarm unit 39 is a means for generating an alarm that the monitor perceives when the deterioration determination unit 19 determines that the battery 2 is deteriorated. For example, the alarm unit 39 may generate light, sound, or both light and sound. good. As a specific example, the alarm unit 39 may be a light emitting diode (LED), a speaker, or a device that generates an image of characters or symbols on the screen of the liquid crystal display device. In this case, the voltage sensor 7 is configured not to have a wireless communication unit. The voltage sensor 7 may be configured such that the entire components including the alarm unit 39 are housed in a common housing (not shown). In the case of this configuration, the voltage sensor 7 can perform deterioration judgment and warning by the sensor alone. Note that the deterioration determination unit 19 may determine whether or not the deterioration is based on a preset threshold value. The other configuration of the voltage sensor 7 of FIG. 12 is the same as that of the first embodiment described with reference to FIGS. 1 to 5B and the like.

In FIG. 1, in more detail, the discharge management unit 22 monitors the battery DC voltage measured by the voltage measurement unit 21, and when it is higher than a set upper limit value, the switch 37 is turned on to turn on the battery 2. During discharging, the battery DC voltage is monitored, and when the voltage falls below a lower limit value set, the switch 37 is turned OFF to stop discharging. The “upper limit value” and the “lower limit value” are values that are arbitrarily determined. For example, the upper limit value and the lower limit value are respectively set to the upper limit or the lower limit of the range of the normal voltage that is a voltage when the battery 2 is not deteriorated.

The deterioration determining unit 19 has a function of setting a discharge condition such as a threshold value in the discharge management unit 22 and a function of controlling the discharge management unit 22 for determining deterioration. Instead of providing the deterioration determination unit 19 in the voltage sensor 7, as described above, the deterioration determination unit 19A may be provided in the information processing facility 11A provided separately from the voltage sensor 7. A part of the deterioration determination unit may be shared by both of the facilities 11A. More specifically, the degradation determination units 19 and 19A have the functions shown in the flowcharts of FIGS. 5A to 11. For example, each timer shown in each flowchart is provided.

Examples of various processing contents of the deterioration determining unit 19 are shown in flowcharts in FIGS. 5A to 11 respectively. The contents of the examples of FIGS. 5A to 11 will be described later. In each figure, each step of starting and stopping the discharge by comparing the measured value of the battery DC voltage with the threshold value sets the discharge management unit 22 in the step. The other steps constitute the deterioration determination unit 19 (19A). Each of FIGS. 5A to 11 includes processing contents of the discharge management unit 22, and is an example of a program of the discharge management deterioration determination unit 19 (19A), for example, and is composed of one sequence program. May be.

In FIG. 1, a hardware configuration example of the voltage sensor 7 will be described. The measurement / control unit 20 and the discharge circuit 35 are mounted on a common circuit board 7A. Therefore, the current limiting resistor 36, the switch 37, and the voltage measuring unit 21 are mounted on a common circuit board. In addition, the measurement / control unit 20 is driven by the power of the battery 2 to be subjected to deterioration determination, and a circuit that supplies power to the measurement / control unit 20 from the battery 2 is a positive / negative cable and a circuit constituting the discharge circuit 35. 38 are shared. Therefore, the circuit that connects the current limiting resistor 36 and the switch 37 to the battery 2 and the circuit that connects the voltage measuring unit 21 to the battery 2 share the positive and negative cables 38. Although not shown, each voltage sensor 7 may have a temperature sensor in addition to the voltage measurement unit 21.

In FIG. 1, the information processing facility 11 </ b> A includes a wireless communication unit 11 a that performs wireless communication with the wireless communication unit 24 of each voltage sensor 7, and a sensor control unit 11 b that controls each voltage sensor 7. . The wireless communication unit 11a has an antenna 11aa. As described above, the deterioration determination unit 19A may or may not be provided in the information processing facility 11A.

Specifically, the information processing facility 11A includes a controller 11, a data server 13, and a monitor 14 as shown in FIG. 3, and the controller 11 includes the wireless communication unit 11a that performs wireless communication with each voltage sensor 7. The sensor control unit 11b is provided, and the data server 13 is provided with the deterioration determination unit 19A. The controller 11 and the data server 13 are connected to each other via the communication network 12. The communication network 12 is a LAN such as a wireless LAN and has a hub 12a. The communication network 12 may be a wide area communication network. The data server 13 can communicate with an information processing device (not shown) such as a remote personal computer through the communication network 12 or another communication network, and can monitor data from anywhere. Communication between the controller 11 and the data server 13 is preferably performed by a handshake method.

The controller 11 is a means for mainly controlling each voltage sensor 7. In addition to the wireless communication unit 11a and the sensor control unit 11b, the controller 11 communicates with the data server 13 and processes a command transmitted from the data server 13. A transfer processing unit 11c for performing The data server 13 includes a command transmission / data storage unit 13b for generating and transmitting commands and storing received data in addition to the deterioration determination unit 19A.

The operation of the above configuration will be described. Details of the function of each part are shown in the following flowcharts. FIG. 4 shows the control operation of the voltage sensor 7 by the data server 13 (FIG. 3) and the controller 11. The data server 13 transmits a measurement start command from the command transmission / data storage unit 13b via the communication network 12D (step M1). The controller 11 receives the measurement start command (step M2) and transmits the measurement start command wirelessly (step M3).

Each voltage sensor 7 simultaneously receives the wireless measurement start command (step M4), and each voltage sensor 7 measures the DC voltage between the battery terminals (step M5). Data such as the measured battery DC voltage (including a temperature measurement value if a temperature sensor is included) is transmitted wirelessly (step M6).

The controller 11 wirelessly receives the transmitted data such as the battery DC voltage (step M7), and transmits the received data via the communication network 12 (step M8). The data server 13 receives the transmitted data such as the battery DC voltage and stores it in the command transmission / data storage unit 13b (step M9). The processes of these steps M6 to M9 are repeatedly performed in order by each voltage sensor 7 (repeated by being NO at step M9), and when data reception / storage from all the voltage sensors 7 is completed, the data server 13 compares with the set value of the battery DC voltage to determine deterioration (step M10). This figure shows an example in which a deterioration determination unit 19A is provided in the data server 13 and the deterioration determination unit 19A performs deterioration determination, and the voltage sensor 7 plays a role of transmitting the measured battery DC voltage.

An example of deterioration determination will be described with reference to FIGS. 5A and 5B. The outline is an example in which the frequency of discharge is determined based on the number of discharges, and deterioration is determined. The discharge is started and stopped at a set voltage value (upper limit value and lower limit value), and within a certain period of time. Measure the number of discharges.

First, a timer (not shown) is started (step N1), and it is determined whether or not the timer count has reached a set time (set by the number of times) (step N2). Until the set time is reached (NO in step N2), the voltage measurement unit 21 of the voltage sensor 7 measures the battery DC voltage (step N9), and the voltage is set by the discharge management unit 22 through step N10A described later. It is determined whether or not the value is higher than a value (a preset threshold value) (step N10). In monitoring the battery DC voltage, the switch 37 may be temporarily turned off to stop discharging (not shown).

In this case, as the threshold value, an upper limit value and a lower limit value are determined before practical use, and in the threshold setting step N10A, the “upper limit value” is set unless discharging is performed as shown in FIG. 5B. Is selected (NO in step R1), and if discharging is in progress, the “lower limit value” is selected and set (YES in step R1). The “upper limit value” and the “lower limit value” are values that are arbitrarily determined, and are set to the upper limit or the lower limit of the range of the normal voltage that is a voltage when the battery 2 is not deteriorated, for example, 2 V For a battery consisting of a single cell, the upper limit value is set to 2.23V, or the upper limit value is set to about 2.23 to 2.4V in consideration of the voltage increase due to charging current and internal resistance. Thus, it is possible to determine the deteriorated battery 2. When the lower limit value is 1.8 V or more and the average value of the DC voltage of each battery is known, the lower limit value is taken as the average value. The lower limit value is set so that a battery having a high voltage is forcibly discharged by the relative comparison and the DC voltages are made uniform. If the voltage between terminals (main power supply 5) of a battery group in which a plurality of batteries are connected in series is known, the voltage obtained by dividing the main power supply 5 by the number of batteries connected in series may be used as a reference. The example of each following figure is also the same as the above.

In step N10, discharge is not initially performed, the threshold value is “upper limit value”, and if the battery DC voltage is higher than the “upper limit value” that is the threshold value (YES in step N10), the switch 37 Discharging by ON is started (step N11), and the process from the measurement of the battery DC voltage (step N9) to the comparison with the threshold value (step N10) is repeated again. During this repetition, the “threshold value” is the “lower limit value” (FIG. 5B), and when it is not higher than the lower limit value (NO in step N10), the discharge is stopped (step N12), and the discharge management unit 22 1 is incremented by 1 (step N13). Thereafter, the process returns to Step N2.

In step N2, when the count of the timer reaches a set time, the timer is stopped (step N3), and the deterioration determination unit 13a is a first set in which the number of discharges counted by the discharge number counter is the first set number. Compared with the threshold value (step N4), if it is less than the first threshold value (YES in step N4), it is determined that the battery 2 is normal (step N5).

The deterioration determining unit 13a compares the number of discharges counted by the discharge number counter with a first threshold value that is the first set number of times (step N4), and if not less than the first threshold value (step S4). N4 is NO) and compared with the second threshold value (step N6). If the threshold value is smaller than the second threshold value (YES in step N6), it is determined that the deterioration is slight and a warning is given (step N7). When the number of discharges counted by the discharge number counter is not less than the second threshold value (NO in step N6), the deterioration determination unit 13a determines that the deterioration is severe and is a warning stronger than the warning. An alarm is issued (step N8). In this way, deterioration determination is performed based on the number of discharges.

FIG. 6 shows an example in which the threshold value for discharging is determined based on the average value of the battery DC voltage of each battery 2 in the processing of FIGS. 5A and 5B. Others are the same as the example of FIG. 5A and FIG. 5B, and the step which performs the same process attaches | subjects the same step number.

In this example, after the battery DC voltage is measured by the voltage sensor 7 (step N9), it is determined whether or not all the voltages of the voltage sensor group 3 that is the target of the power source 1 have been measured (step N10a). Until the voltage of 2 is measured, the voltage of the battery 2 is measured. The measured battery DC voltage is stored in a predetermined storage area. When the voltages of all the batteries 2 are measured (YES in step N10a), the average value of the battery DC voltage is calculated (step N10b). Although not shown in the figure, a value obtained by adding a preset addition value and subtraction value to the average value is set as a threshold value that is an upper limit value and a lower limit value.

Thereafter, the measured battery DC voltage of each battery 2 is compared with a threshold value (step N10d). Although not shown in the figure, prior to this comparison, as described with reference to FIG. 5B, the threshold value is set to the upper limit if not discharging, and the threshold value is set if discharging is in progress. Is set to the lower limit value. The battery DC voltage measured by the battery 2 is compared with a threshold value. If the battery DC voltage measured by the battery 2 is higher than the upper limit (YES in step N10d), discharging is started (step N11). Voltage measurement (step N10c) and comparison with the threshold value (step N10d. Similarly, comparison with the threshold value is also performed in step O2d described later) are repeated. In the repetitive process, since the battery is being discharged at step N10d, the battery DC voltage is compared with the lower limit value. If the battery DC voltage is not higher than the lower limit value, the discharge is stopped (step N12).

Other processes are the same as those in the example of FIGS. 5A and 5B, and thus redundant description is omitted. Thus, by determining the upper limit value and the lower limit value of the voltage for discharging and stopping discharge based on the average value, it is possible to perform more appropriate discharge for each individual power source and improve the accuracy of deterioration determination. .

FIG. 7 shows a first example in which the deterioration determination based on the discharge frequency is performed based on the discharge interval time. Here, the time from the end of discharge to the start of the next discharge is compared. First, the battery DC voltage is measured by the voltage sensor 7 (step O1), and it is determined whether or not the voltage is higher than a preset threshold value that is a set value of the voltage (step O2).

In this case, before step O2, an upper limit value and a lower limit value are determined as the threshold values, and as described with reference to FIG. If discharging is in progress, the “lower limit value” is selected and set. Initially, since the discharge has not yet been performed, the threshold value is the upper limit value. If the battery DC voltage is not higher than the upper limit value (NO in step O2), the discharge is stopped (maintains the stop even when the discharge is stopped) (step O5), and the timer start step (step O6) is performed (step O6). Timer not shown). In this step O6, the timer is started in the first loop that is “charging” and whose state has changed since charging. Therefore, we will not start this time. Thereafter, the process returns to the battery DC voltage measurement process (step O1).

In the next determination process (step O2), since the discharge is stopped, it is compared with the upper limit value. If it is higher than the upper limit value (YES in step O2), discharge is started (step O3) and the timer is stopped (step O4). However, if the timer is stopped, the stop is maintained. In the determination process of whether or not it is the next first discharge (step O7), since it is the first discharge (YES in step O7), the process returns to the battery DC voltage measurement process (step O1). In this embodiment, the determination as to whether or not the discharge is the first discharge (step O7) is performed. In this embodiment, after starting, a “flag indicating discharge” (not shown) is “0”. The “indicating flag” is “1”, and the “indicating discharging flag” is “2” after the end of discharging (during charging). Thereafter, when the “flag indicating discharge” is “2”, “2” is maintained. When the “flag indicating discharge” is “1”, the process returns to step O1. In other flowcharts, the charts are simplified based on the same idea as described above.

In the next determination process (step O2), since it is discharging, it is compared with the lower limit value, and when it falls below the lower limit value, the discharge is stopped (step O5) (end of discharge) and the timer is started (step). O6). Thereafter, the process returns to the battery DC voltage measurement process (step O1). In the next determination process (step O2), since the discharge is stopped, it is compared with the upper limit value, and when it is higher than the upper limit value (YES in step O2), discharge is started (step O3) (next discharge Start), the timer is stopped (step O4).

In the next step O7 for determining whether or not it is the first discharge, since this is not the first discharge this time (NO in step O7), the process proceeds to step O8, and the next discharge starts from the time of the timer, that is, the end of the discharge. Is obtained as a discharge interval.

It is determined whether or not the discharge interval is longer than a first threshold value that is a set value of the interval (step O9). When the discharge interval is longer than the first threshold value, it is determined as normal (step O10). If it is not longer than the first threshold value, it is compared with the second threshold value (step O11). If it is longer than the second threshold value, it is judged as mild deterioration and a warning is issued (step O12). If it is not longer than the second threshold value, it is determined that the deterioration is severe, and an alarm that is stronger than the alarm is issued (step O13). Thus, even if it determines with a discharge interval, deterioration of a battery can be determined easily. It can be determined that the discharge interval is short.

FIG. 8 shows an example in which the threshold value for discharging in the example of FIG. 7 is determined based on the average value of the battery DC voltage of each battery 2 as in the example of FIG. The other steps are the same as in the example of FIG. 7, and steps that perform the same processing are given the same step numbers.

In this example, after the measurement of the battery DC voltage by the voltage sensor 7 (step O1), it is determined whether or not all the voltages of the voltage sensor group 3 that is the target of the power source 1 have been measured (step O2aa). Until the voltage of 2 is measured, the voltage of the battery 2 is measured. The measured battery DC voltage is stored in a predetermined storage area. When the voltages of all the batteries 2 are measured, the average value of the battery DC voltage is calculated (step O2b), and a value obtained by adding a preset addition value or subtraction value to the average value is set as an upper limit value and a lower limit value, respectively. Determine. Since each other process is the same as the example of FIG. 7, the overlapping description is omitted.

FIG. 9 shows an example in which the frequency of discharge is determined by measuring the interval between the discharge start and discharge stop times at two voltage setting values (upper limit value and lower limit value). The battery DC voltage is measured by the voltage sensor 7 (step P1), and it is determined whether or not it is higher than a preset threshold value that is a set value of the voltage (step P2). In this case, as the threshold value, an upper limit value and a lower limit value are determined in advance at the time of design, and before step P2, as described with reference to FIG. Select and set “Lower limit” if discharging is in progress. If it is determined in step P2 that the battery DC voltage is higher than the upper limit (YES in step P2), discharging is started (step P3), a timer (not shown) is started (step P4), and step P1. Return to. Note that the timer start step P4 does not restart the timer for each loop process, but starts the timer in the first loop in which the state has changed from the discharge state during “discharging”.

After the measurement of the battery DC voltage (step P1), if the battery DC voltage is not higher than the threshold value (lower limit value) in the determination process of step P2 (NO in step 2P), the discharge is stopped (step P5). ), The timer is stopped (step P6), and the discharge time which is the time measured by the timer is acquired (step P7). It is determined whether or not the acquired discharge time is longer than a first threshold value that is a set value of time (step P8). If it is longer (YES in step P8), it is determined that the discharge is normal (step P9). ). If the acquired discharge time is not longer than the first threshold value which is the set time (NO in step P8), the discharge time is compared with the second threshold value (step P10), and the second If it is longer than the threshold value (YES in step P10), it is determined that the deterioration is slight and a warning is given (step P11). If the discharge time is not longer than the second threshold value (NO in step P10), it is determined that the deterioration is severe and an alarm that is stronger than the alarm is given (step P12).

The example of FIG. 10 shows an example in which the threshold value for discharging in the example of FIG. 9 is determined based on the average value of the battery DC voltage of each battery 2 as in the examples of FIGS. The other steps are the same as in the example of FIG. 9, and steps that perform the same processing are given the same step numbers.

In this example, after the battery DC voltage is measured by the voltage sensor 7 (step P1), it is determined whether or not all the voltages of the voltage sensor group 3 that is the target of the power source 1 have been measured (step P2aa). Until the voltage of 2 is measured, the voltage of the battery 2 is measured. The measured battery DC voltage is stored in a predetermined storage area. When the voltages of all the batteries 2 are measured, an average value of the battery DC voltage is calculated (step P2b), and a value obtained by adding a preset addition value to the average value is used as a threshold value to measure each battery 2. The battery DC voltage is compared with a threshold value (step P2).
Thereafter, processing is performed in the same manner as in the example shown in FIG.

FIG. 11 is an example of counting the number of discharges in a certain time. First, a first timer (not shown) is started (step Q1), and it is determined whether or not the timer has reached a set time (measured by the number of counts) (step Q2). If the set time has not been reached (NO in step Q2), the battery DC voltage is measured by the voltage sensor 7 (step Q9), and it is determined whether or not it is higher than a preset threshold value that is a set value of the voltage. (Step Q10). In this case, as the threshold value, an upper limit value and a lower limit value are determined in advance at the time of design, and, prior to step Q10, as in the example described with reference to FIG. If the battery is discharging, select and set the “lower limit value”.

When the battery DC voltage measured by the voltage sensor 7 is higher than the threshold value (YES in step Q10), discharging is started (step Q11), and a second timer (timer for measuring discharge time) ( (Not shown) is started (step Q12). It is determined whether or not the second timer (not shown) has reached the set time (step Q13). When the second timer (not shown) reaches, the discharge is stopped (step Q14), and the second timer (not shown) is stopped. (Step Q15), the discharge counter is incremented by 1 (Step Q16). Thereafter, the process returns to step Q9, and the processes of steps 9 to 16 are repeated. However, in the determination at step Q10, the threshold value is a lower limit value.

During this time, the time is measured by the first timer. When the first timer reaches the set time (YES in step Q2), the first timer is stopped (step Q3), and the number of discharges is the number of times and the set value. It is determined whether it is less than a certain first threshold value (step Q4). If the number of discharges is less than the first threshold value (YES in step Q4), it is determined as normal (step Q5). If the number of discharges is not less than the first threshold value (NO in step Q4), it is determined whether or not the number of discharges is less than the second threshold value (step Q6). If the number of discharges is less than the first threshold (YES in step Q6), it is determined that the deterioration is slight and a warning is issued (step Q7). If the number of discharges is not less than the first threshold value (NO in step Q6), an alarm that is more severe than the warning is output (step Q8).

This deterioration determination device for a secondary battery determines deterioration as in each of the above examples, and provides the following advantages. When the battery 2 deteriorates, the internal resistance increases. Therefore, if the individual battery 2 DC voltage is measured, the deterioration of the battery 2 can be determined to some extent. However, since the fluctuation of the battery DC voltage also occurs due to other factors, it is not possible to accurately determine the deterioration of the battery simply by measuring the voltage between the terminals.

However, when the battery DC voltage is high, this deterioration determination device consumes energy by the current limiting resistor 36 by discharging and measures again, and determines deterioration by the discharge frequency. The influence of fluctuation does not appear, and it is possible to determine the deterioration of the battery with a certain degree of accuracy. Further, since no means for applying a measurement current to the battery 2 is required, the apparatus has a simple configuration. Thus, it is possible to determine the deterioration of the secondary battery with a certain degree of accuracy with a simple configuration. Therefore, it is suitable for prevention of deterioration in an emergency power source in which a large number of batteries 2 are connected to dozens or hundreds. In addition, since the battery is discharged when the battery DC voltage is high, there is an advantage that it is avoided that the deteriorated battery is overcharged and the deterioration is accelerated.

Further, for example, when the deterioration determination units 19 and 19A determine the number of discharges as the determination process of the deterioration based on the discharge frequency, the deterioration of the battery 2 can be easily determined. In addition, when the deterioration determination unit 19 or 19A measures the discharge interval as the determination of deterioration due to the discharge frequency and determines based on the discharge interval, the deterioration of the battery can be easily determined.

Since the deterioration determination device consumes energy with the current limiting resistor 36 and discharges as described above, rapid discharge is suppressed. However, after the discharge is started, the switch 37 is temporarily turned off at regular intervals. By doing so, the battery DC voltage during discharge can be measured. The battery deterioration can also be accurately determined by measuring the voltage in this way and repeating the comparison with the set value and comparing the discharge interval with the set interval.

The “voltage setting value” may be a fixed value, but an appropriate battery DC voltage may be slightly different depending on each power source. Therefore, as described above, the average value of the battery DC voltages of all the batteries is obtained, and the set value of the voltage for discharging is determined based on this average value, so that more appropriate discharge can be performed for each individual power source. The accuracy of deterioration determination can be improved.

As described above, when the current limiting resistor 36 and the switch 37 are mounted on the same circuit board 7A as the voltage measuring unit 21, the device is simplified and made compact. Further, when the circuit of the current limiting resistor 36 and the switch 37 and the circuit of the voltage measuring unit 21 share a cable connected to the battery, the cable wiring is simplified.

Each of the deterioration determination devices of the above embodiments is provided with a plurality of voltage sensors 5 each having the voltage measurement unit 21, the discharge circuit 35, and the discharge management unit 22, and one unit for each of the voltage sensors 5. Since the information processing device 11A includes the deterioration determination unit 13a, the information processing device performs the deterioration determination of each battery in the emergency power source to which dozens, hundreds, and many batteries are connected. Only one unit is required, and the configuration is simplified.

As mentioned above, although the suitable form for implementing this invention based on embodiment was demonstrated referring drawings, embodiment disclosed here is an illustration and restrictive at no points. The scope of the present invention is shown not by the above description but by the claims. Those skilled in the art will readily appreciate various changes and modifications within the obvious scope upon reviewing this specification. Therefore, such changes and modifications should be construed as being within the scope of the invention defined by the claims or within the scope equivalent thereto.

DESCRIPTION OF SYMBOLS 1 ... Power supply 2 ... Battery 3 ... Battery group 4 ... Load 5 ... Main power supply 5A, 5B ... Terminal 6 ... Charging circuit 7 ... Voltage sensor 7A ... Circuit board 11 ... Controller 11A ... Information processing equipment 11a ... Wireless communication part 11b ... Sensor Control unit 11c ... Transfer processing unit 12 ... Communication network 13 ... Data server 13b ... Command transmission / data storage unit 14 ... Monitor 15 ... Diode 18 ... Discharge management degradation determination unit 19 ... Degradation determination unit 19A ... Degradation determination unit 20 ... Measurement -Control part 21 ... Voltage measurement part 22 ... Discharge management part 23 ... Operation control part 24 ... Wireless communication part 25 ... AC voltage measurement part 27 ... Operation control part 30 ... Discharge part 32 ... Discharge process part 35 ... Discharge circuit 36 ... Current Limit resistor 37 ... Switch 38 ... Cable 39 ... Alarm unit

Claims (11)

A voltage measuring unit that measures a DC voltage between terminals of a battery that is a secondary battery, a discharge circuit that is a series circuit of a current limiting resistor and a switch connected in parallel with the battery, and a voltage measuring unit. The battery DC voltage is monitored, and if it is higher than the set upper limit value, the switch is turned on to discharge the battery, and during this ON, the battery DC voltage is monitored to be lower than the lower limit value set. Then, a discharge management unit that turns off the switch to stop discharge and a deterioration determination unit that measures the discharge frequency of the discharge circuit under the control of the discharge management unit and determines the deterioration of the battery based on the discharge frequency. Secondary battery deterioration determination device. The deterioration determination device for a secondary battery according to claim 1, wherein the deterioration determination unit measures the number of discharges performed within a set time as a process for determining deterioration due to the discharge frequency, and sets the number of discharges. A secondary battery deterioration determination device that determines that the battery has deteriorated if the number of times is greater than the number of times. The deterioration determination apparatus for a secondary battery according to claim 1, wherein the deterioration determination unit measures a discharge interval between a previous discharge and a current discharge as a determination of deterioration due to the discharge frequency, and the discharge interval is a set interval. A deterioration determination device for a secondary battery that determines that the battery has deteriorated if shorter than. The deterioration determination device for a secondary battery according to claim 1, wherein the deterioration determination unit measures a switching time that is a time between the start of the discharge and the stop of the discharge as the determination of the deterioration due to the discharge frequency. And the deterioration determination apparatus of the secondary battery which determines with the battery having deteriorated when the discharge time which is this switching time is shorter than setting time. 2. The secondary battery deterioration determination device according to claim 1, wherein the discharge management unit starts discharging in response to the battery DC voltage being higher than the upper limit value as processing for determining deterioration due to the discharge frequency. 3. Thereafter, the switch is temporarily turned off at regular intervals, and when the battery DC voltage measured by the voltage measurement unit becomes lower than the lower limit value, the switch is maintained in the OFF state, and the voltage monitoring is performed. The number of discharges within a set time when the comparison with the upper limit value, the temporary switch OFF, the comparison with the lower limit value, and the maintenance of the switch in the OFF state are repeated. A deterioration determination device for a secondary battery, wherein the deterioration determination unit determines that the battery has deteriorated if the amount of the battery is larger. 6. The secondary battery deterioration determination device according to claim 1, wherein the deterioration determination device determines the deterioration of the battery of a power source in which a plurality of batteries are connected in series. The voltage measurement unit, the discharge circuit, and the discharge management unit, wherein the deterioration determination unit, after the voltage measurement by all the voltage measurement unit of the plurality of batteries is performed, of the measured battery DC voltage A secondary battery deterioration determination device that obtains an average value and determines the upper limit value and the lower limit value based on the average value. 7. The secondary battery deterioration determination device according to claim 1, wherein the current limiting resistor and the switch are mounted on the same circuit board as the voltage measurement unit. Degradation judgment device. 8. The secondary battery deterioration determination device according to claim 1, wherein the current limiting resistor and the switch circuit, and the voltage measurement unit circuit are connected to the battery. 9. Degradation suppression device for secondary battery sharing cable. 9. The secondary battery deterioration determination device according to claim 1, wherein a plurality of voltage sensors each having the voltage measurement unit, the discharge circuit, and the discharge management unit, and the voltage sensors. The secondary battery deterioration determination device is configured to include an operation command for these voltage sensors and an information processing facility that collects data by measuring or processing each of the voltage sensors. 10. The secondary battery deterioration determination apparatus according to claim 9, wherein the information processing facility includes the deterioration determination unit or a unit constituting a part of the deterioration determination unit. The deterioration determination device for a secondary battery according to any one of claims 1 to 8, further comprising: an alarm unit that generates an alarm to be perceived by a monitor when the deterioration determination unit determines that the battery is deteriorated. A secondary battery deterioration determination device in which the voltage measurement unit, the discharge circuit, the discharge management unit, the deterioration determination unit, and the alarm unit are housed in a common housing.

Images