JP2022042807A - Battery control system and computer program - Google Patents

Abstract

To increase the freedom of choice of a battery.SOLUTION: A battery control system (1) according to an embodiment includes a plurality of connecting devices (3) to which a plurality of battery packs (10) are connected, and a control device (30) that controls the operation of the plurality of battery packs (10). The control device (30) acquires the first upper limit output of each of the plurality of battery packs (10), and uses the first upper limit output of the plurality of battery packs (10) to calculate a second upper limit output of a battery unit (20) including the plurality of battery packs (10). The control device (30) controls the operation of the plurality of battery packs (10) on the basis of the calculated second upper limit output of the battery unit (20).SELECTED DRAWING: Figure 4

Description

The present invention relates to a battery control system that combines and discharges a plurality of battery packs.

Machines that operate on the electric power supplied from the battery include, for example, electric vehicles and electric auxiliary vehicles. Generally, these vehicles are equipped with a battery, and the electric motor is rotated by the electric power supplied from the battery, and the vehicle can run. The battery is rechargeable and can be used repeatedly by charging.

In recent years, it has been proposed to configure a stationary power storage system using a used battery used in a vehicle or the like as described above. The stationary power storage system can be used in a power generation facility that utilizes renewable energy, such as a photovoltaic power generation facility.

Patent Document 1 discloses a battery control device that controls a plurality of batteries. In Patent Document 1, the degree of deterioration of each battery is determined from the temperature, SOC, and the like, and the output ratio between the plurality of batteries is adjusted based on the degree of deterioration. This makes it possible to appropriately control the charge / discharge amount of each of the plurality of batteries.

Patent Document 2 discloses a battery control device that determines the degree of deterioration from the internal resistance of the battery and preferentially discharges the battery having the smaller degree of deterioration. By preferentially using batteries with a low degree of deterioration, the degree of deterioration is made uniform among a plurality of batteries, and the life of the entire system is extended.

Japanese Unexamined Patent Publication No. 2019-041550 Japanese Patent No. 4572850

The battery control device disclosed in Patent Documents 1 and 2 is premised on using a plurality of batteries having the same specifications. When there is a difference in measured values such as internal resistance between multiple batteries due to the same specifications, the degree of deterioration among multiple batteries is used using a table or map showing the relationship between the measured values and the degree of deterioration. It is possible to grasp the magnitude relationship of.

However, for example, when reusing a used battery, it may be required not only to use a combination of batteries having the same specifications but also to use a combination of batteries having different specifications from each other. In this case, it is difficult to evaluate the temperature, SOC, internal resistance, etc. of each battery on the same scale, and it is difficult to judge the relative deterioration degree of each battery. It is difficult to apply the control methods disclosed in Patent Documents 1 and 2 to a combination of batteries having different specifications from each other, and the degree of freedom in selecting a battery is low.

The present invention provides a battery control system with increased flexibility in battery selection.

The battery control system according to an embodiment of the present invention is a battery control system including a plurality of connection devices to which a plurality of battery packs are connected and a control device for controlling the operation of the plurality of battery packs. The control device acquires the first upper limit output of each of the plurality of battery packs, and uses the first upper limit output of the plurality of battery packs to obtain the second upper limit output of the battery unit including the plurality of battery packs. The operation of the plurality of battery packs is controlled based on the calculation and the calculated second upper limit output of the battery unit.

In the present invention, the second upper limit output of the battery unit is calculated using the first upper limit output of the plurality of battery packs, and the plurality of battery packs are controlled based on the calculated second upper limit output of the battery unit.

The upper limit output can be obtained for each battery pack regardless of whether the specifications of the plurality of battery packs are the same or different from each other, and the discharge of the combination of the plurality of battery packs is controlled based on this upper limit output. Even if the specifications differ between multiple battery packs, the upper limit output is a common physical quantity among those battery packs. Therefore, by evaluating each battery pack using the upper limit output, the battery packs can be combined even if the specifications differ between the plurality of battery packs. This makes it possible to improve the degree of freedom in selecting the battery pack.

In one embodiment, even if the discharge of at least one of the plurality of battery packs is restricted, the second upper limit output of the battery unit is larger than the power consumption of the load connected to the battery control system. , The control device may perform control to limit the discharge of the at least one battery pack.

If limiting the discharge of at least one battery pack yields an upper limit output that is greater than the power consumption of the load, limit the discharge of at least one battery pack to efficiently distribute multiple battery packs. Can be used. For example, deterioration of the battery pack that limits the discharge can be suppressed.

In one embodiment, the plurality of battery packs are three or more battery packs, and the control device is a third upper limit output of each of the plurality of groups obtained by combining two or more of the plurality of battery packs. May be calculated and the third upper limit output, which is the maximum among the third upper limit outputs of the plurality of groups, may be set as the second upper limit output of the battery unit.

Depending on the state of a plurality of battery packs, the upper limit output does not always increase as the number of combined battery packs increases. The third upper limit output of each of a plurality of groups having different combinations of battery packs is calculated, and the maximum upper limit output among them is set as the second upper limit output of the battery unit. By adopting the maximum output that can be obtained from the combination of multiple battery packs, it is possible to discharge by making the best use of the capacity of multiple battery packs.

In one embodiment, the first group, which is one of the plurality of groups, includes a first battery pack, and the control device is a battery having the lowest voltage among the battery packs included in the first group. When the pack is the first battery pack, the voltage of the first battery pack is set as the reference voltage, and the ratio of each of the voltages of the other battery packs included in the first group to the reference voltage is calculated. Then, based on the calculated ratio, the duty ratio applied to each of the other battery packs is calculated, and the first upper limit output of each of the other battery packs when the calculated duty ratio is applied is calculated. , The value obtained by adding the first upper limit output of the other battery pack calculated and the first upper limit output of the first battery pack may be acquired as the third upper limit output of the first group.

The voltages output from each of the battery packs included in the first group can be adjusted to the same magnitude, and the battery packs included in the first group can be connected in parallel and discharged. Further, it is possible to acquire the third upper limit output of the first group in a form in which the battery packs included in the first group are connected in parallel and discharged.

By performing the above operation for each of the plurality of groups, the third upper limit output of each of the plurality of groups can be acquired.

In certain embodiments, even if the discharge of at least one of the battery packs included in the group having the maximum third upper limit output among the plurality of groups is restricted, the battery pack is connected to the battery control system. When the second upper limit output of the battery unit is larger than the power consumption of the load, the control device may perform control to limit the discharge of the at least one battery pack.

If limiting the discharge of at least one battery pack yields an upper limit output that is greater than the power consumption of the load, limit the discharge of at least one battery pack to efficiently distribute multiple battery packs. Can be used. For example, deterioration of the battery pack that limits the discharge can be suppressed.

In one embodiment, the control device selects one group from the plurality of groups whose third upper limit output is larger than the power consumption of the load connected to the battery control system, and the selected group. You may control to discharge the battery pack contained in.

This makes it possible to supply the power required for the load.

In a certain embodiment, when there are two or more groups in the plurality of groups whose third upper limit output is larger than the power consumption of the load connected to the battery control system, the control device is the plurality of groups. Control to select one group having a larger third upper limit output than the power consumption other than the group having the maximum third upper limit output, and to discharge the battery pack included in the selected group. May be done.

By selecting a group other than the group that maximizes the third upper limit output, a plurality of battery packs can be used efficiently. For example, by selecting a group that does not use one or more of the plurality of battery packs, deterioration of the unused battery packs can be suppressed.

In one embodiment, when the control device selects one group from the plurality of groups, the control device selects the group among the plurality of battery packs that does not include the battery pack having the minimum first upper limit output. Then, control may be performed to discharge the battery pack included in the selected group.

It is considered that the battery pack having a small first upper limit output has a small remaining capacity or is deteriorated. By not using the battery pack having a small first upper limit output for discharging, stable discharging can be performed. Further, for a battery pack having a small remaining capacity, charging can be prioritized over discharging. In addition, deterioration of the unused battery pack can be suppressed.

In one embodiment, when the control device selects one group from the plurality of groups, the control device selects the group among the plurality of battery packs that does not include the battery pack having the maximum first upper limit output. Then, control may be performed to discharge the battery pack included in the selected group.

It is considered that the battery pack having a large first upper limit output has a large remaining capacity or has not deteriorated. When the battery control system is used, for example, as a charging station for an electric vehicle, it is desirable that the remaining capacity of the battery pack to be replaced with the empty battery pack mounted on the electric vehicle is large. Further, it is desirable that a battery pack that has not been deteriorated is mounted on the electric vehicle.

By not using the battery pack having a large first upper limit output for discharging in the battery control system, the battery pack can be mounted on the electric vehicle. Further, even when the battery pack having a large upper limit output is removed from the battery control system for mounting on an electric vehicle, the discharge operation of the battery control system can be continued.

In one embodiment, when discharging a battery pack included in a group selected from the plurality of groups, the controller controls the voltage of the battery pack having the lowest voltage among the battery packs included in the selected group. May be set to the reference voltage, and control may be performed to adjust each of the voltages output from the other battery packs included in the selected group to the reference voltage.

By adjusting the voltages output from each of the battery packs included in the group selected for discharging to the same magnitude, the battery packs included in the group can be connected in parallel and discharged.

In certain embodiments, the control device may adjust each of the voltages output from the other battery packs to the reference voltage by PWM (Pulse Width Modulation) control.

By PWM control, the voltages output from each battery pack can be adjusted to the same magnitude.

In one embodiment, the battery packs included in the selected group are discharged in a state of being connected in parallel to each other, and among the battery packs not included in the selected group, the battery pack having an output voltage lower than the reference voltage is used. The positive electrode terminal may be connected to the parallel connection node via a diode.

If the magnitude of the load changes abruptly, the output voltage of the battery control system may drop abruptly. When the output voltage of the battery control system becomes lower than the output voltage of the non-selective battery pack connected via the diode, the non-selective battery pack also supplies power to the load. This can prevent the battery control system from going down.

In a certain embodiment, when the magnitude relationship of the third upper limit output of the plurality of groups changes in the process of discharging the battery pack included in the selected group, the control device may change the group to be discharged. good.

As the remaining capacity of the battery pack decreases due to discharge, the magnitude relationship of the third upper limit output of the plurality of groups changes. In this case, by changing the discharge group, it is possible to discharge in a more appropriate group.

In one embodiment, the control device calculates a first upper limit output of the battery pack based on the detected value of the voltage of the battery pack and the upper limit current of the battery pack corresponding to the detected value of the voltage. You may.

The calculated first upper limit output of the battery pack can be used to calculate the second upper limit output of the battery unit including the plurality of battery packs.

In one embodiment, at least one of the plurality of battery packs may differ from the other battery packs in specifications.

By combining battery packs with each other using the upper limit output, it is possible to combine battery packs with different specifications. This makes it possible to improve the degree of freedom in selecting the battery pack.

A computer program according to an embodiment of the present invention is a computer program that causes a computer to control the operation of a plurality of battery packs, and the computer program acquires a first upper limit output of each of the plurality of battery packs. That, the second upper limit output of the battery unit including the plurality of battery packs is calculated by using the first upper limit output of the plurality of battery packs, and the second upper limit output of the battery unit is calculated based on the calculated second upper limit output. Have the computer perform control over the operation of multiple battery packs.

According to the battery control system according to an embodiment of the present invention, the second upper limit output of the battery unit is calculated using the first upper limit output of a plurality of battery packs, and the calculated second upper limit output of the battery unit is calculated. Control the operation of multiple battery packs. The upper limit output can be obtained for each battery pack regardless of whether the specifications of the plurality of battery packs are the same or different from each other, and the discharge of the combination of the plurality of battery packs is controlled based on this upper limit output. Even if the specifications differ between multiple battery packs, the upper limit output is a common physical quantity among those battery packs. Therefore, by evaluating each battery pack using the upper limit output, the battery packs can be combined even if the specifications differ between the plurality of battery packs. This makes it possible to improve the degree of freedom in selecting the battery pack.

It is a perspective view which shows the battery control system 1 which concerns on embodiment of this invention. It is a perspective view which shows the state of attachment / detachment of the battery pack 10 in the battery control system 1 which concerns on embodiment of this invention. It is a figure which shows the battery control system 1 and the battery pack 10 which concerns on embodiment of this invention. It is a flowchart which shows the discharge operation of the battery control system 1 which concerns on embodiment of this invention. It is a flowchart which shows the process which calculates the 2nd upper limit output of the battery unit 20 which concerns on embodiment of this invention. It is a figure which shows an example of the calculation of the 2nd upper limit output of the battery unit 20 which concerns on embodiment of this invention. It is a figure which shows another example of the calculation of the 2nd upper limit output of the battery unit 20 which concerns on embodiment of this invention. It is a figure which shows the plurality of groups obtained from the plurality of battery packs 10 which concerns on embodiment of this invention. It is a flowchart which shows the process of changing the group to be discharged when the magnitude relation of the 3rd upper limit output among a plurality of groups which concerns on embodiment of this invention changes. It is a flowchart which shows the process of changing the group to be discharged according to the magnitude relation between the 2nd upper limit output of the battery unit 20 and the power consumption of a load 71 which concerns on embodiment of this invention.

Hereinafter, the battery control system according to the embodiment of the present invention will be described with reference to the drawings. In the description of the embodiment, similar components are designated by the same reference numerals, and the description thereof will be omitted if they are duplicated. The following embodiments are examples, and the present invention is not limited to the following embodiments.

FIG. 1 is a perspective view showing a battery control system 1 according to an embodiment of the present invention. The battery control system 1 charges and discharges by combining a plurality of battery packs 10. The battery control system 1 is used, for example, as a stationary power storage system. The stationary power storage system can be used in power generation equipment that utilizes renewable energy, such as solar power generation equipment and wind power generation equipment. The stationary power storage system can also be used as an emergency power source in the event of a disaster or the like.

The battery control system 1 includes a housing 2 and a plurality of connectors (connecting devices) 3 provided in the housing 2. The number of connectors 3 is any number of 2 or more. A battery pack 10 is connected to each of the plurality of connectors 3. The battery unit 20 is composed of one or more battery packs 10 out of a plurality of battery packs 10, and the battery control system 1 discharges the battery unit 20 as one unit.

The housing 2 of the battery control system 1 is provided with a charging connector 4, a discharging connector 5, and 6. The charging connector 4 is connected to a power generation device such as a solar power generation device and a wind power generation device, and the battery pack 10 can be charged by the power generated by the power generation device. Further, for example, the battery pack 10 may be charged by connecting the charging connector 4 to an arbitrary power source such as a household power source.

The discharge connectors 5 and 6 are connected to, for example, a load (external device). The electric power output from the battery pack 10 constituting the battery unit 20 is output from the discharge connectors 5 and 6. DC power is output from the discharge connector 5. AC power is output from the discharge connector 6. Depending on the application of the battery control system 1, the battery control system 1 may include only one of the discharge connectors 5 and 6.

Each of the battery packs 10 is removable with respect to the battery control system 1. FIG. 2 is a perspective view showing a state of attachment / detachment of one battery pack 10 in the battery control system 1. The battery control system 1 charges the battery pack 10 connected to the connector 3. The charged battery pack 10 can be, for example, removed from the battery control system 1 and attached to machines such as an electric vehicle and an electric auxiliary vehicle to be used as a power source. In a vehicle equipped with the battery pack 10, the electric motor is rotated by the electric power supplied from the battery pack 10, and the vehicle can run.

The battery pack 10 that has been used in the vehicle and has a low remaining capacity can be charged by removing it from the vehicle and connecting it to the connector 3 of the battery control system 1. Then, by removing another charged battery pack 10 from the battery control system 1 and attaching it to the vehicle, the vehicle can run again. As described above, the battery control system 1 can be used as a charging station for replacing the empty battery pack 10 mounted on the vehicle with the charged battery pack 10.

FIG. 3 is a diagram showing a battery control system 1 and a battery pack 10.

In order to explain the embodiment of the present invention in an easy-to-understand manner, the following description mainly describes an embodiment in which three battery packs 10 are connected to the battery control system 1, but the embodiment of the present invention is not limited thereto. The number of battery packs 10 connected to the battery control system 1 is arbitrary, and may be two or four or more, and the present invention can be applied to those forms. In the example shown in FIG. 3, three battery packs 10a, 10b, and 10c are connected to the battery control system 1 as the battery pack 10.

The battery pack 10 includes a plurality of cell cells (cells) 11, a battery management system (BMS) 12, and a connector 13. The BMS 12 controls various operations such as charging and discharging of the battery pack 10, and monitors various states of the battery pack 10. The BMS 12 monitors the voltage, current, temperature, SOC (State of Charge), SOH (State of Health), and the like of the battery pack 10. The battery pack 10 is connected to the battery control system 1 by connecting the connector 13 of the battery pack 10 to the connector 3 of the battery control system 1. The current output from the plurality of cell cells 11 is supplied to the battery control system 1 via the BMS 12 and the connector 13.

In the battery control system 1, a plurality of battery packs 10a, 10b, and 10c are connected in parallel to each other. The battery pack 10a is connected to the converter 41 and the inverter 42 via a switching element 51 for PWM (Pulse Width Modulation), a diode 61, and a switching element 54 for discharging. The battery pack 10b is connected to the converter 41 and the inverter 42 via a switching element 52 for PWM, a diode 62, and a switching element 54 for discharging. The battery pack 10c is connected to the converter 41 and the inverter 42 via a switching element 53 for PWM, a diode 63, and a switching element 54 for discharging.

When the load (external device) 71 is connected to the discharge connector 6, the inverter 42 converts the input DC voltage into an AC voltage and outputs it to the load 71. When the load 71 is connected to the discharge connector 5, the converter 41 adjusts the magnitude of the input DC voltage and outputs the load 71 to the load 71. Depending on the application of the battery control system 1, the battery control system 1 may include only one of the converter 41 and the inverter 42.

When the power generation device 73 is connected to the charging connector 4, the electric power output from the power generation device 73 is input to the charger 43 via the charging connector 4 and the charging switching element 55. The charger 43 adjusts the magnitudes of the voltage and the current, and outputs the voltage and the current to the battery pack 10. When charging the battery pack 10a, the current output from the charger 43 is supplied to the battery pack 10a via the diode 64 and the connector 3. When charging the battery pack 10b, the current output from the charger 43 is supplied to the battery pack 10b via the diode 65 and the connector 3. When charging the battery pack 10c, the current output from the charger 43 is supplied to the battery pack 10c via the diode 66 and the connector 3.

The switching elements 51, 52, 53, 54, 55 are, for example, field effect transistors (FETs), but the switching elements are not limited to field effect transistors, and any switching element can be used.

The control device 30 controls the operation of the battery control system 1. The control device 30 includes a processor 31, a memory 32, and a communication circuit 33. The processor 31 is a signal processing circuit (computer) that controls the operation of the battery control system 1. Typically, the processor 31 is a semiconductor integrated circuit.

The memory 32 stores a computer program for causing the processor 31 to control the operation of the battery control system 1. Such a computer program may be installed in the battery control system 1 from a recording medium (semiconductor memory, optical disk, etc.) on which it is recorded, or may be downloaded via a telecommunications line such as the Internet. Further, such a computer program may be installed in the battery control system 1 via wireless communication. Such computer programs may be sold as packaged software. The processor 31 executes a computer program stored in the memory 32 to control the operation of the battery control system 1.

The processor 31 communicates with the BMS 12 of the battery pack 10 via the communication circuit 33. The processor 31 transmits / receives necessary information to / from the BMS 12 when charging / discharging the battery pack 10. Further, the processor 31 receives information such as voltage, current, and temperature of the battery pack 10 from the BMS 12.

The processor 31 controls the operations of the converter 41, the inverter 42, the charger 43, and the switching elements 51, 52, 53, 54, 55. During the discharge operation of the battery control system 1, the processor 31 turns on the switching element 54. The processor 31 executes PWM control by repeatedly switching the switching elements 51, 52, and 53 on and off. The DC voltage modulated by the PWM control is input to the converter 41 or the inverter 42. During the charging operation of the battery pack 10, the processor 31 turns on the switching element 55 and controls the operation of the charger 43 to supply electric power to the battery pack 10 for charging.

When charging, the switching element corresponding to the battery pack 10 to be charged among the switching elements 51, 52, and 53 may be turned off. For example, it is assumed that the voltage of the battery pack 10c is the lowest among the battery packs 10a, 10b, and 10c, and the battery pack 10c is charged. When charging the battery pack 10c, by turning off the switching element 53, it is possible to prevent the charging current from flowing to the discharge side of the circuit. As a result, the battery pack 10c can be charged while discharging the battery packs 10a and 10b. As described above, in the battery control system 1, charging and discharging can be performed in parallel. It is possible to eliminate the discrepancy between the voltage of the battery pack 10c to be charged and the voltages of the battery packs 10a and 10b to be discharged, and after the battery pack 10c is charged to a desired level, the battery pack 10c is replaced with the battery pack 10a. And can be discharged with 10b.

Further, when charging, the switching element corresponding to the battery pack 10 to be charged among the switching elements 51, 52, and 53 may be turned on. For example, when charging the battery pack 10c, the switching element 53 is turned on. In this case, a part of the charging current flows to the discharge side of the circuit. That is, a part of the electric power output from the charger 43 is used as electric power for discharging. Since the current output from the battery pack 10c to be charged is reduced, the difference between the voltage of the battery pack 10c and the voltages of the battery packs 10a and 10b can be reduced.

Next, the discharge operation of the battery control system 1 will be described in more detail.

FIG. 4 is a flowchart showing the discharge operation of the battery control system 1. As described above, in the battery control system 1, a battery unit 20 including one or more battery packs 10 out of a plurality of battery packs 10 is configured, and the battery unit 20 is used as one unit for discharging.

First, the processor 31 (FIG. 3) acquires the upper limit output of each of the plurality of battery packs 10 connected to the battery control system 1 (step S10). The upper limit output of the battery pack 10 is an upper limit value of the electric power that can be output by the battery pack 10. The upper limit output varies depending on the current state of the battery pack 10. For example, the upper limit output changes depending on the SOC, temperature, and the like. In the following description, the upper limit output of the battery pack 10 is expressed as "first upper limit output".

The BMS 12 of the battery pack 10 detects the voltage of the battery pack 10. The BMS 12 acquires the upper limit current of the battery pack 10 corresponding to the detected value of the voltage. The upper limit current is an upper limit value of the current that can be output by the battery pack 10 at that time when the voltage of the battery pack 10 is the detected magnitude. For example, the BMS 12 stores in advance a map showing the relationship between the voltage and the upper limit current. The BMS 12 can obtain the upper limit current from the detected value of the voltage using such a map. The BMS 12 outputs the voltage detection value and the upper limit current value to the processor 31. The processor 31 acquires the first upper limit output of the battery pack 10 by multiplying the detected value of the voltage and the value of the upper limit current. The BMS 12 may acquire the first upper limit output by multiplying the voltage detection value and the upper limit current value, and may output the acquired first upper limit output value to the processor 31.

The processor 31 constitutes a battery unit 20 including one or more battery packs 10 out of a plurality of battery packs 10. The processor 31 calculates the upper limit output of the battery unit 20 (step S11). The upper limit output of the battery unit 20 is an upper limit value of the electric power that can be output by the battery unit 20. In the following description, the upper limit output of the battery unit 20 is expressed as "second upper limit output". The processor 31 calculates the upper limit output of the battery unit 20 by using, for example, the first upper limit output of each of the battery packs 10 included in the battery unit 20.

FIG. 5 is a flowchart showing a process of calculating the second upper limit output of the battery unit 20. FIG. 6 is a diagram showing an example of calculation of the second upper limit output of the battery unit 20. FIG. 7 is a diagram showing another example of the calculation of the second upper limit output of the battery unit 20. FIG. 8 is a diagram showing a plurality of groups including one or more battery packs 10 among a plurality of battery packs 10.

With reference to FIG. 8, when the number of battery packs 10 is 3, the number of groups including one or more battery packs 10 is 7. FIG. 8 shows these seven groups 80i, 80j, 80k, 80l, 80m, 80n, 80o. The processor 31 calculates the upper limit output of each of the plurality of groups 80i, 80j, 80k, 80l, 80m, 80n, and 80o. The upper limit output of a group is the upper limit of the power that the group can output. In the following description, the upper limit output of the group is expressed as "third upper limit output".

The processor 31 receives a voltage detection value and an upper limit current value from the BMS 12 of each battery pack 10. FIG. 6 shows an example of the voltage and the upper limit current of the battery packs 10a, 10b, and 10c. The first upper limit output of each battery pack 10 is obtained by multiplying the voltage by the upper limit current.

With reference to FIG. 5, the processor 31 identifies a battery pack 10 that belongs to one of a plurality of groups (step S20). For example, it is specified that the battery packs belonging to the group 80i are the battery packs 10a, 10b, and 10c.

The processor 31 identifies the battery pack having the lowest voltage from the battery packs 10a, 10b, and 10c belonging to the group 80i (step S21). In the example shown in FIG. 6, the battery pack 10a is specified as the battery pack having the lowest voltage. The processor 31 sets the voltage 21.0 (V) of the battery pack 10a, which has the lowest voltage, as the reference voltage.

The processor 31 calculates the ratio of the voltage of each of the other battery packs 10b and 10c belonging to the group 80i to the reference voltage. In the example shown in FIG. 6, the voltage ratio of the battery pack 10b is 0.84, and the voltage ratio of the battery pack 10c is 0.71.

The processor 31 calculates a duty ratio (DT ratio) applied to the PWM control of each of the battery packs 10a, 10b, and 10c (step S22). The duty ratio is obtained by squared the voltage ratio.

The processor 31 calculates the first upper limit output of each of the battery packs 10a, 10b, and 10c when the calculated duty ratio is applied (step S23). In the example shown in FIG. 6, the first upper limit output of the battery pack 10a is 210 (W), the first upper limit output of the battery pack 10b is 266 (W), and the first upper limit output of the battery pack 10c is 300 (W). ..

The processor 31 adds the first upper limit outputs when these duty ratios are applied to acquire the third upper limit output of the group (step S24). In the example shown in FIG. 6, 776 (W) is acquired as the third upper limit output of the group 80i.

In step S25, the processor 31 determines whether or not the third upper limit output of all groups has been calculated. If the calculation of the third upper limit output of all the groups is not completed, the process returns to the process of step S20, and the process is performed for the group for which the calculation has not yet been completed.

In the example shown in FIG. 6, the processor 31 identifies the battery pack 10b having the lowest voltage among the battery packs 10b and 10c belonging to the group 80j. The processor 31 sets the voltage 25.0 (V) of the battery pack 10b, which has the lowest voltage, as the reference voltage. Then, the same processing as described above is performed, and 798 (W) is acquired as the third upper limit output of the group 80j.

Further, the processor 31 identifies the battery pack 10a having the lowest voltage from the battery packs 10a and 10c belonging to the group 80k. The processor 31 sets the voltage 21.0 (V) of the battery pack 10a, which has the lowest voltage, as the reference voltage. Then, the same processing as described above is performed, and 510 (W) is acquired as the third upper limit output of the group 80k. Similarly, the processor 31 calculates the third upper limit output of the group 80l. In FIG. 6, an example of calculation of the third upper limit output of the group 80l is omitted. Further, when there is one battery pack 10 belonging to a group as in the groups 80m, 80n, and 80o shown in FIG. 8, the third upper limit output of the group is the first upper limit output of the battery pack 10 belonging to the group. Will be.

When the calculation of the third upper limit output of all the groups is completed, the process proceeds to step S26 (FIG. 5). In step S26, the processor 31 selects the third upper limit output, which is the largest among the third upper limit outputs of all the groups. The processor 31 sets the selected third upper limit output as the second upper limit output of the battery unit 20. In the example shown in FIG. 6, the third upper limit output 798 (W) of the group 80j is the maximum value. The processor 31 sets its 798 (W) as the second upper limit output of the battery unit 20.

FIG. 7 shows another example of the calculation of the second upper limit output of the battery unit 20. The states of the battery packs 10a, 10b, and 10c shown in FIG. 7 are different from those in FIG. The same processing as described above is performed on the battery packs 10a, 10b, and 10c in the state shown in FIG. 7. The processor 31 selects the third upper limit output, which is the largest among the third upper limit outputs of all groups. In the example shown in FIG. 7, the third upper limit output 705 (W) of the group 80i is the maximum value. The processor 31 sets its 705 (W) as the second upper limit output of the battery unit 20.

With reference to FIG. 4, the processor 31 controls the discharge of each battery pack 10 based on the calculated second upper limit output of the battery unit 20 (step S12). When the third upper limit output 798 (W) of the group 80j shown in FIG. 6 is set as the second upper limit output of the battery unit 20, the battery unit 20 is composed of the battery packs 10b and 10c belonging to the group 80j. The processor 31 discharges the battery packs 10b and 10c constituting the battery unit 20.

The processor 31 sets the voltage 25.0 (V) of the battery pack 10b, which has the lowest voltage among the battery packs 10b and 10c, as the reference voltage. The processor 31 adjusts the voltage 29.4 (V) output from the other battery pack 10c to the reference voltage 25.0 (V) by PWM control. By adjusting the voltages output from each of the battery packs 10b and 10c belonging to the group 80j selected for discharging to have the same magnitude, the battery packs 10b and 10c belonging to the group 80j are connected in parallel and discharged. Can be made to.

When the third upper limit output 705 (W) of the group 80i shown in FIG. 7 is set as the second upper limit output of the battery unit 20, the battery unit 20 is composed of the battery packs 10a, 10b, and 10c belonging to the group 80i. The processor 31 discharges the battery packs 10a, 10b, and 10c constituting the battery unit 20.

The processor 31 sets the voltage 21.0 (V) of the battery pack 10a, which has the lowest voltage among the battery packs 10a, 10b, and 10c, as the reference voltage. The processor 31 adjusts the voltage output from the other battery packs 10b and 10c to the reference voltage 21.0 (V) by PWM control. By adjusting the voltages output from each of the battery packs 10a, 10b, and 10c belonging to the group 80i selected for discharging to have the same magnitude, the battery packs 10a, 10b, and 10c belonging to the group 80i are arranged in parallel. Can be connected and discharged.

The electric power output by the battery control system 1 is supplied to the load 71. When the discharge is terminated, such as when the load 71 stops operating, the processor 31 terminates the discharge control (step S13).

As described above, in the battery control system 1 of the present embodiment, the second upper limit output of the battery unit 20 is calculated using the first upper limit output of the plurality of battery packs 10, and the calculated second upper limit of the battery unit 20 is calculated. The discharge of a plurality of battery packs 10 is controlled based on the output.

In the present embodiment, at least one of the plurality of battery packs 10 connected to the battery control system 1 may have different specifications from the other battery packs 10. The specifications may differ from each other among the plurality of battery packs 10.

The upper limit output can be obtained for each battery pack 10 regardless of whether the specifications of the plurality of battery packs 10 are the same or different from each other, and the discharge of the combination of the plurality of battery packs 10 is controlled based on the upper limit output. .. Even if the specifications differ among the plurality of battery packs 10, the upper limit output is a common physical quantity among the battery packs 10. Therefore, by evaluating each battery pack 10 using the upper limit output, the battery packs 10 can be combined with each other even if the specifications of the plurality of battery packs 10 are different from each other. This makes it possible to improve the degree of freedom in selecting the battery pack 10.

Further, depending on the state of the plurality of battery packs 10, the third upper limit output does not necessarily increase as the number of combined battery packs 10 increases. For example, in the state of the battery packs 10a, 10b, and 10c shown in FIG. 6, the third upper limit output when the two battery packs 10b and 10c are combined is the maximum. The third upper limit output of each of a plurality of groups having different combinations of the battery packs 10 is calculated, and the maximum third upper limit output is set as the second upper limit output of the battery unit 20. By adopting the maximum third upper limit output obtained from the combination of the plurality of battery packs 10, it is possible to discharge by making the best use of the capacity of the plurality of battery packs 10.

Next, a process of changing the group to be discharged when the magnitude relationship of the third upper limit output between the plurality of groups changes will be described.

For example, the states of the battery packs 10a, 10b, and 10c at the start of discharging are the states shown in FIG. 6, and it is assumed that the battery packs 10b and 10c belonging to the group 80j are discharged. It is assumed that the voltages of the battery packs 10b and 10c gradually decrease in the process of continuing the discharge, and the state shown in FIG. 7 is reached. In the state shown in FIG. 7, the third upper limit output 705 (W) of the group 80i is larger than the third upper limit output 595 (W) of the group 80j. In this case, the group to be discharged may be changed from the group 80j to the group 80i.

FIG. 9 is a flowchart showing a process of changing the group to be discharged when the magnitude relationship of the third upper limit output between the plurality of groups changes.

The processor 31 periodically calculates the third upper limit output of each of the plurality of groups while discharging the battery pack 10 constituting the battery unit 20 (step S30). The calculation method of the third upper limit output is as described above.

The processor 31 determines whether or not the magnitude relationship of the third upper limit output between the plurality of groups has changed (step S31). For example, when the battery packs 10a, 10b, and 10c change from the state shown in FIG. 6 to the state shown in FIG. 7, the magnitude relationship of the third upper limit output between the plurality of groups changes.

When it is determined that the magnitude relationship of the third upper limit output has not changed, the processor 31 periodically repeats the calculation of the third upper limit output of each of the plurality of groups.

When it is determined that the magnitude relationship of the third upper limit output has changed, the processor 31 identifies a group in which the third upper limit output is larger than the power (power consumption) required by the load (step S32). Regarding the power consumption of the load, the processor 31 may receive information on the power consumption from the load (external device), or may be estimated from the voltage and current output from the battery control system 1. For example, when the battery packs 10a, 10b, and 10c are in the state shown in FIG. 7, and the power consumption of the load is 500 (W), the processor 31 identifies the groups 80i and 80j.

The processor 31 selects a group to be discharged from the groups 80i and 80j (step S33). For example, when giving priority to discharge with a margin, the group 80i having the largest third upper limit output is selected as the group to be discharged. That is, the group to be discharged is changed from the group 80j to the group 80i. For example, when the priority is given to limiting the discharge of the battery pack 10a and suppressing the deterioration of the battery pack 10a, the discharge of the group 80j is maintained.

When the magnitude relationship of the third upper limit output changes, the group to be discharged may always be changed to the group having the largest third upper limit output. As a result, it is possible to perform discharging by making the best use of the capacity of the plurality of battery packs 10.

When the discharge is terminated, such as when the load 71 stops operating, the processor 31 terminates the discharge control (step S34).

Next, a process of changing the discharge group according to the magnitude relationship between the second upper limit output of the battery unit 20 and the power consumption of the load 71 will be described.

FIG. 10 is a flowchart showing a process of changing the discharge group according to the magnitude relationship between the second upper limit output of the battery unit 20 and the power consumption of the load 71.

The processor 31 determines whether the second upper limit output of the battery unit 20 is larger than the power consumption of the load 71 (step S40). When it is determined that the second upper limit output is larger than the power consumption, the processor 31 determines whether the group to be discharged can be changed to the group having a smaller third upper limit output (step S41).

For example, assume that the battery packs 10a, 10b, and 10c are in the state shown in FIG. 7, and the group 80i is being selected as the group to be discharged. When the power consumption of the load is 500 (W), it is possible to respond to the request from the load even if the group 80j is selected. In this case, the processor 31 changes the group to be discharged from the group 80i to the group 80j (step S43).

The change from the group 80i to the group 80j is synonymous with limiting the discharge of the battery pack 10a included in the group 80i. Even if the discharge of at least one of the battery packs 10 included in the group having the third upper limit output is limited, the second upper limit output of the battery unit 20 is larger than the power consumption of the load 71. If so, the processor 31 may control to limit the discharge of at least one battery pack 10. As a result, deterioration of the battery pack 10 that limits the discharge can be suppressed.

If priority is given to discharge with a margin, the selection of the group 80i having the largest third upper limit output may be maintained in step S43.

When the discharge is terminated, such as when the load 71 stops operating, the processor 31 terminates the discharge control (step S44).

When it is determined in step S40 that the second upper limit output of the battery unit 20 is equal to or less than the power consumption of the load 71, the processor 31 determines whether there is a group in which the third upper limit output is larger than the power consumption. If it is determined that the processor 31 exists, the processor 31 changes the group to be discharged to a group whose third upper limit output is larger than the power consumption (step S43). When it is determined that there is no group whose third upper limit output is larger than the power consumption, the discharge control is terminated.

In the process shown in FIG. 10, when there are two or more groups having a third upper limit output larger than the power consumption of the load 71, a group other than the group having the maximum third upper limit output can be selected. In the above example, the third upper limit output of the groups 80i and 80j is larger than the power consumption of the load 71. In this case, the processor 31 may select a group 80j other than the group 80i having the maximum third upper limit output. By selecting a group that does not use one or more of the plurality of battery packs 10, deterioration of the unused battery pack 10 can be suppressed.

When selecting a group to be discharged from a plurality of groups, a group that does not include the battery pack 10 having the minimum first upper limit output among the plurality of battery packs 10 may be selected. It is considered that the battery pack 10 having a small first upper limit output has a small remaining capacity or is deteriorated. By not using the battery pack 10 having a small first upper limit output for discharging, stable discharging can be performed. Further, for the battery pack 10 having a small remaining capacity, charging can be prioritized over discharging. In addition, deterioration of the unused battery pack 10 can be suppressed.

Further, when selecting a group to be discharged from a plurality of groups, the group 80 which does not include the battery pack 10 having the maximum first upper limit output among the plurality of battery packs 10 may be selected. It is considered that the battery pack 10 having a large first upper limit output has a large remaining capacity or has not been deteriorated. When the battery control system 1 is used, for example, as a charging station for an electric vehicle, it is desirable that the remaining capacity of the battery pack 10 to be replaced with the empty battery pack 10 mounted on the electric vehicle is large. Further, it is desirable that the battery pack 10 which has not been deteriorated is mounted on the electric vehicle. By not using the battery pack 10 having a large first upper limit output for discharging in the battery control system 1, the battery pack 10 can be mounted on the electric vehicle. Further, even when the battery pack 10 having a large upper limit output is removed from the battery control system 1 for mounting on an electric vehicle, the discharge operation of the battery control system 1 can be continued.

As described with reference to FIG. 3, the plurality of battery packs 10 are connected to the converter 41 and the inverter 42 via the diodes 61, 62, 63. The battery packs 10 included in the group selected for discharging are discharged in a state of being connected in parallel with each other. For example, when group 80j is selected, the battery packs 10b and 10c are discharged in parallel with each other. At this time, the positive electrode terminal of the battery pack 10a not included in the group 80j is connected to the node 68 connected in parallel via the diode 61. The switching element 51 is turned on. Since the voltage of the battery pack 10a is lower than the reference voltage of the group 80j, no current flows from the battery pack 10a.

If the power consumption of the load 71 suddenly increases during discharging, the output voltage of the battery control system 1 may drop sharply. When the voltage of the node 68 becomes lower than the voltage of the battery pack 10a, a current flows through the diode 61, and the battery pack 10a also supplies electric power to the load 71. By connecting the non-selective battery pack 10 to the node 68 connected in parallel via the diode in this way, the battery control system 1 can be brought down even if the power consumption of the load 71 suddenly increases. Can be suppressed.

In the above description, the voltage of the battery pack 10 having the lowest voltage among the battery packs 10 included in the group is set as the reference voltage, but the present invention is not limited thereto. The voltage of the battery pack 10 other than the battery pack 10 having the lowest voltage may be set as the reference voltage. In this case, for the battery pack 10 having a voltage lower than the reference voltage, by boosting the voltage, the voltage output from each of the battery packs 10 included in the same group is adjusted to be the same magnitude as each other. May be good.

The exemplary embodiments of the present invention have been described above.

The battery control system 1 according to an embodiment of the present invention includes a plurality of connection devices 3 to which a plurality of battery packs 10 are connected, and a control device 30 for controlling the operation of the plurality of battery packs 10. The control device 30 acquires the first upper limit output of each of the plurality of battery packs 10, and uses the first upper limit output of the plurality of battery packs 10 to obtain the second upper limit output of the battery unit 20 including the plurality of battery packs 10. Calculation is performed, and the operation of the plurality of battery packs 10 is controlled based on the calculated second upper limit output of the battery unit 20.

In the embodiment of the present invention, the second upper limit output of the battery unit 20 is calculated using the first upper limit output of the plurality of battery packs 10, and the plurality of battery packs are calculated based on the calculated second upper limit output of the battery unit 20. 10 is controlled.

The upper limit output can be obtained for each battery pack 10 regardless of whether the specifications of the plurality of battery packs 10 are the same or different from each other, and the discharge of the combination of the plurality of battery packs 10 is controlled based on the upper limit output. .. Even if the specifications differ among the plurality of battery packs 10, the upper limit output is a common physical quantity among the battery packs 10. Therefore, by evaluating each battery pack 10 using the upper limit output, the battery packs 10 can be combined with each other even if the specifications of the plurality of battery packs 10 are different from each other. This makes it possible to improve the degree of freedom in selecting the battery pack 10.

In one embodiment, even if the discharge of at least one of the plurality of battery packs 10 is restricted, the second upper limit output of the battery unit 20 is larger than the power consumption of the load 71 connected to the battery control system 1. In this case, the control device 30 may perform control to limit the discharge of at least one battery pack 10.

If the upper limit output larger than the power consumption of the load 71 can be obtained even if the discharge of at least one battery pack 10 is limited, the discharge of at least one battery pack 10 is limited to limit the discharge of the plurality of battery packs 10. Can be used efficiently. For example, deterioration of the battery pack 10 that limits the discharge can be suppressed.

In one embodiment, the plurality of battery packs 10 are three or more battery packs 10, and the control device 30 is a third of each of the plurality of groups 80 obtained by combining two or more of the plurality of battery packs 10. The upper limit output may be calculated, and the third upper limit output, which is the maximum among the third upper limit outputs of the plurality of groups 80, may be set as the second upper limit output of the battery unit 20.

Depending on the state of the plurality of battery packs 10, the upper limit output does not always increase as the number of combined battery packs 10 increases. The third upper limit output of each of the plurality of groups 80 having different combinations of the battery packs 10 is calculated, and the maximum upper limit output among them is set as the second upper limit output of the battery unit 20. By adopting the maximum upper limit output obtained from the combination of the plurality of battery packs 10, it is possible to discharge by making the best use of the capacity of the plurality of battery packs 10.

In one embodiment, the first group, which is one of the plurality of groups 80, includes the first battery pack 10a, and the control device 30 has the lowest voltage among the battery packs 10 included in the first group. When the battery pack 10 is the first battery pack 10a, the voltage of the first battery pack 10a is set as the reference voltage, and the ratio of each of the voltages of the other battery packs 10 included in the first group to the reference voltage is set. Based on the calculated ratio, the duty ratio applied to each of the other battery packs 10 is calculated, and the first upper limit output of each of the other battery packs 10 when the calculated duty ratio is applied is calculated. The value obtained by adding the calculated first upper limit output of the other battery pack 10 and the first upper limit output of the first battery pack 10a may be acquired as the third upper limit output of the first group.

The voltages output from each of the battery packs 10 included in the first group can be adjusted to have the same magnitude, and the battery packs 10 included in the first group can be connected in parallel and discharged. Further, it is possible to acquire the third upper limit output of the first group in a form in which the battery packs 10 included in the first group are connected in parallel and discharged.

By performing the above operation for each of the plurality of groups 80, it is possible to acquire the third upper limit output of each of the plurality of groups 80.

In one embodiment, even if the discharge of at least one of the battery packs 10 included in the group having the maximum third upper limit output among the plurality of groups 80 is restricted, the battery control system 1 is connected. When the second upper limit output of the battery unit 20 is larger than the power consumption of the load 71, the control device 30 may perform control to limit the discharge of at least one battery pack 10.

If the upper limit output larger than the power consumption of the load 71 can be obtained even if the discharge of at least one battery pack 10 is limited, the discharge of at least one battery pack 10 is limited to limit the discharge of the plurality of battery packs 10. Can be used efficiently. For example, deterioration of the battery pack 10 that limits the discharge can be suppressed.

In a certain embodiment, the control device 30 selects one group from a plurality of groups 80 having a third upper limit output larger than the power consumption of the load 71 connected to the battery control system 1, and sets the selected group. Control may be performed to discharge the included battery pack 10. As a result, the required electric power can be supplied to the load 71.

In a certain embodiment, when there are two or more groups in the plurality of groups 80 having a third upper limit output larger than the power consumption of the load 71 connected to the battery control system 1, the control device 30 has a plurality of groups. Among the groups 80, one group other than the group having the maximum third upper limit output and having a third upper limit output larger than the power consumption is selected, and the battery pack 10 included in the selected group is controlled to be discharged. May be good.

By selecting a group other than the group that maximizes the third upper limit output, the plurality of battery packs 10 can be used efficiently. For example, by selecting a group that does not use one or more of the plurality of battery packs 10, deterioration of the unused battery pack 10 can be suppressed.

In one embodiment, when the control device 30 selects one group from the plurality of groups 80, the control device 30 selects the group among the plurality of battery packs 10 that does not include the battery pack 10 having the minimum first upper limit output. Then, control may be performed to discharge the battery pack 10 included in the selected group.

It is considered that the battery pack 10 having a small first upper limit output has a small remaining capacity or is deteriorated. By not using the battery pack 10 having a small first upper limit output for discharging, stable discharging can be performed. Further, for the battery pack 10 having a small remaining capacity, charging can be prioritized over discharging. In addition, deterioration of the unused battery pack 10 can be suppressed.

In one embodiment, when the control device 30 selects one group from the plurality of groups 80, the control device 30 selects the group among the plurality of battery packs 10 that does not include the battery pack 10 having the maximum first upper limit output. Then, control may be performed to discharge the battery pack 10 included in the selected group.

It is considered that the battery pack 10 having a large first upper limit output has a large remaining capacity or has not been deteriorated. When the battery control system 1 is used, for example, as a charging station for an electric vehicle, it is desirable that the remaining capacity of the battery pack 10 to be replaced with the empty battery pack 10 mounted on the electric vehicle is large. Further, it is desirable that the battery pack 10 which has not been deteriorated is mounted on the electric vehicle.

By not using the battery pack 10 having a large first upper limit output for discharging in the battery control system 1, the battery pack 10 can be mounted on the electric vehicle. Further, even when the battery pack 10 having a large upper limit output is removed from the battery control system 1 for mounting on an electric vehicle, the discharge operation of the battery control system 1 can be continued.

In one embodiment, when discharging the battery pack 10 included in a group selected from a plurality of groups 80, the control device 30 has the lowest voltage among the battery packs 10 included in the selected group. The voltage may be set to the reference voltage, and control may be performed to adjust each of the voltages output from the other battery packs 10 included in the selected group to the reference voltage.

By adjusting the voltages output from each of the battery packs 10 included in the group selected for discharging to the same magnitude, the battery packs 10 included in the group can be connected in parallel and discharged.

In one embodiment, the control device 30 may adjust each of the voltages output from the other battery pack 10 to a reference voltage by PWM (Pulse Width Modulation) control. By PWM control, the voltages output from each of the battery packs 10 can be adjusted to the same magnitude.

In one embodiment, the battery packs 10 included in the selected group 80 are discharged in parallel with each other, and among the battery packs 10 not included in the selected group 80, the battery packs having an output voltage lower than the reference voltage are used. The positive electrode terminal of 10 may be connected to the node 68 connected in parallel via the diode 61, 62 or 63.

If the magnitude of the load 71 changes abruptly, the output voltage of the battery control system 1 may drop abruptly. When the output voltage of the battery control system 1 becomes lower than the output voltage of the non-selective battery pack 10 connected via the diode 61, 62 or 63, the non-selective battery pack 10 also supplies power to the load 71. Will be done. As a result, it is possible to prevent the battery control system 1 from going down.

In one embodiment, when the magnitude relationship of the third upper limit output of the plurality of groups 80 changes in the process of discharging the battery pack 10 included in the selected group 80, the control device 30 changes the group to be discharged. May be good.

As the remaining capacity of the battery pack 10 decreases due to the discharge, the magnitude relationship of the third upper limit output of the plurality of groups 80 changes. In this case, by changing the group 80 to be discharged, it is possible to discharge in a more appropriate group 80.

In one embodiment, the control device 30 calculates a first upper limit output of the battery pack 10 based on the voltage detection value of the battery pack 10 and the upper limit current of the battery pack 10 corresponding to the voltage detection value. May be good. The calculated first upper limit output of the battery pack 10 can be used to calculate the second upper limit output of the battery unit 20 including the plurality of battery packs 10.

In one embodiment, at least one of the plurality of battery packs 10 may differ from the other battery packs 10 in specifications.

By combining the battery packs 10 with each other using the upper limit output, the battery packs 10 having different specifications can be combined. This makes it possible to improve the degree of freedom in selecting the battery pack 10.

A computer program according to an embodiment of the present invention causes a computer to control the operation of a plurality of battery packs 10. The computer program obtains the first upper limit output of each of the plurality of battery packs 10, and uses the first upper limit output of the plurality of battery packs 10 to obtain the second upper limit output of the battery unit 20 including the plurality of battery packs 10. The computer is made to perform the calculation and control the operation of the plurality of battery packs 10 based on the calculated second upper limit output of the battery unit 20.

The present invention is particularly useful in the technical field of combining and discharging a plurality of battery packs.

1: Battery control system, 2: Housing, 3: Connector (connecting device), 4: Charging connector, 5: Discharging connector, 6: Discharging connector, 10: Battery pack, 11: Cell (single battery), 12: Battery management system (BMS), 13: Connector, 20: Battery unit, 30: Control device, 31: Processor, 32: Memory, 33: Communication circuit, 41: Converter, 42: Inverter, 43: Charger, 51 52, 53: PWM switching element, 54: discharge switching element, 55: charging switching element, 61, 62, 63, 64, 65, 66: diode, 68: node, 71: load (external device), 73: Power generator, 80: Group

Claims (16)

With multiple connecting devices to which multiple battery packs are connected,
A control device that controls the operation of the plurality of battery packs,
It is a battery control system equipped with
The control device is
Obtain the first upper limit output of each of the plurality of battery packs,
Using the first upper limit output of the plurality of battery packs, the second upper limit output of the battery unit including the plurality of battery packs is calculated.
A battery control system that controls the operation of the plurality of battery packs based on the calculated second upper limit output of the battery unit. If even if the discharge of at least one of the plurality of battery packs is restricted, the second upper limit output of the battery unit is larger than the power consumption of the load connected to the battery control system, the control device is used. The battery control system according to claim 1, wherein the control is performed to limit the discharge of at least one battery pack. The plurality of battery packs are three or more battery packs, and the plurality of battery packs are three or more battery packs.
The control device is
The third upper limit output of each of the plurality of groups obtained by combining two or more of the plurality of battery packs is calculated.
The battery control system according to claim 1 or 2, wherein the third upper limit output, which is the maximum among the third upper limit outputs of the plurality of groups, is set as the second upper limit output of the battery unit. The first group, which is one of the plurality of groups, includes the first battery pack.
The control device is
When the battery pack having the lowest voltage among the battery packs included in the first group is the first battery pack, the voltage of the first battery pack is set as the reference voltage.
The ratio of each of the voltages of the other battery packs included in the first group to the reference voltage is calculated.
Based on the calculated ratio, the duty ratio applied to each of the other battery packs is calculated.
The first upper limit output of each of the other battery packs when the calculated duty ratio is applied is calculated.
The battery according to claim 3, wherein the value obtained by adding the first upper limit output of the other battery pack calculated and the first upper limit output of the first battery pack is acquired as the third upper limit output of the first group. Control system. Even if the discharge of at least one of the battery packs included in the group having the maximum third upper limit output among the plurality of groups is restricted, the power consumption of the load connected to the battery control system is limited. The battery control system according to claim 3 or 4, wherein the control device controls to limit the discharge of the at least one battery pack when the second upper limit output of the battery unit is larger than that of the battery unit. The control device is
From the plurality of groups, one group having the third upper limit output larger than the power consumption of the load connected to the battery control system is selected.
The battery control system according to any one of claims 3 to 5, which controls the discharge of the battery pack included in the selected group. When there are two or more groups in the plurality of groups whose third upper limit output is larger than the power consumption of the load connected to the battery control system, the control device determines.
Among the plurality of groups, one group having a larger third upper limit output than the power consumption other than the group having the maximum third upper limit output is selected.
The battery control system according to any one of claims 3 to 6, wherein the battery pack included in the selected group is controlled to be discharged. When the control device selects one group from the plurality of groups, the control device selects a group among the plurality of battery packs that does not include the battery pack having the minimum first upper limit output.
The battery control system according to any one of claims 3 to 7, wherein the battery pack included in the selected group is controlled to be discharged. When the control device selects one group from the plurality of groups, the control device selects the group among the plurality of battery packs that does not include the battery pack having the maximum first upper limit output.
The battery control system according to any one of claims 3 to 7, wherein the battery pack included in the selected group is controlled to be discharged. When discharging the battery pack included in the group selected from the plurality of groups,
The control device is
The voltage of the battery pack with the lowest voltage among the battery packs included in the selected group is set as the reference voltage.
The battery control system according to any one of claims 3 to 9, wherein the control is performed to adjust each of the voltages output from the other battery packs included in the selected group to the reference voltage. The battery control system according to claim 10, wherein the control device adjusts each of the voltages output from the other battery packs to the reference voltage by PWM (Pulse Width Modulation) control. The battery packs included in the selected group are discharged in parallel with each other and discharged.
13. Battery control system. The control device changes the group to be discharged when the magnitude relation of the third upper limit output of the plurality of groups changes in the process of discharging the battery pack included in the selected group, according to claims 6 to 12. The battery control system described in either. The control device calculates the first upper limit output of the battery pack based on the detected value of the voltage of the battery pack and the upper limit current of the battery pack corresponding to the detected value of the voltage, according to claim 1. 13. The battery control system according to any one of 13. The battery control system according to any one of claims 1 to 14, wherein at least one of the plurality of battery packs has different specifications from the other battery packs. A computer program that allows a computer to control the operation of multiple battery packs.
The computer program is
Obtaining the first upper limit output of each of the plurality of battery packs,
Using the first upper limit output of the plurality of battery packs to calculate the second upper limit output of the battery unit including the plurality of battery packs.
A computer program that causes the computer to control the operation of the plurality of battery packs based on the calculated second upper limit output of the battery unit.

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