WO2014049655A1 - Electricity storage system - Google Patents

Description

Power storage system

The present invention relates to a power storage system including a plurality of storage battery modules connected in parallel.

In recent years, power storage systems using lithium ion batteries have become widespread. Lithium ion batteries have a high energy density and are advantageous for miniaturization and weight reduction. Storage systems using lithium ion batteries are expected to accelerate in the future.

Since a lithium ion battery has a low internal resistance, a larger current tends to flow in a power storage system using a lithium ion battery than in a power storage system using a lead battery during a short circuit. As the capacity of the power storage system is increased, the number of parallel storage battery modules is increasing, and the value of the short-circuit current flowing at the time of a short circuit is also increasing. In this way, high-spec overcurrent protection is required in power storage systems.

JP 2010-81721 A

In order to reduce the cost of the storage system, in addition to the storage battery itself, cost reduction of its peripheral elements is also required. In particular, lithium ion batteries are more expensive than other batteries, and thus cost reduction of peripheral elements is also important.

The present invention has been made in view of such circumstances, and an object thereof is to provide a technique for constructing overcurrent protection in a power storage system at low cost while ensuring performance.

A power storage system according to an aspect of the present invention includes a circuit breaker inserted in a current path connecting a plurality of storage battery modules connected in parallel, the plurality of storage battery modules, and a charge / discharge device that charges and discharges the plurality of storage battery modules. And comprising. The plurality of storage battery modules are divided into a plurality of groups. The current paths of the storage battery modules belonging to each group are connected in parallel to form a plurality of group current paths. A plurality of group current paths are coupled in parallel and connected to the charge / discharge device. The circuit breaker includes a plurality of open / close sections inserted into the plurality of group current paths. When one opening / closing part of the plurality of opening / closing parts is opened, the remaining opening / closing parts are also opened in conjunction with each other.

According to the present invention, overcurrent protection in a power storage system can be constructed at low cost while ensuring performance.

It is a figure which shows the structure of the electrical storage system which concerns on the comparative example 1. It is a figure which shows the structure of the electrical storage system which concerns on the comparative example 2. It is a figure which shows the example of 1 structure of the electrical storage system which concerns on embodiment of this invention. It is a figure which shows another structural example of the electrical storage system which concerns on embodiment of this invention. 5 is a table describing the number of parallel storage battery units in FIG. 4 and the relationship between the open / close units used. It is a figure which shows the modification of the electrical storage system of FIG.

FIG. 1 is a diagram illustrating a configuration of a power storage system 100 according to Comparative Example 1. The power storage system 100 according to the comparative example 1 includes a storage battery unit 10, a circuit breaker 20, a control device 30, and a charge / discharge device 40. The charging / discharging device 40 includes a bidirectional converter 41 and a control unit 42. The storage battery unit 10 according to Comparative Example 1 is formed by connecting three storage battery modules, a first storage battery module 11, a second storage battery module 12, and a third storage battery module 13, in parallel.

Each storage battery module includes a plurality of storage battery cells connected in series and a monitoring unit that monitors the state of the plurality of storage battery cells. Hereinafter, in this specification, it is assumed that a lithium ion battery is used as the storage battery cell. The monitoring unit includes a current sensor, a voltage sensor, and a temperature sensor (not shown), and constantly monitors the current, voltage, and temperature of each storage battery cell. The monitoring unit transmits monitoring data to the control device 30 according to an instruction from the control unit 42. In the storage battery module, a plurality of storage battery cells may be connected in parallel, or connected in multiple lines.

The circuit breaker 20 is inserted into a current path connecting the storage battery unit 10 and the charge / discharge device 40. In the power storage system 100 shown in FIG. 1, the plus terminal of the bidirectional converter 41, the plus terminal of the storage battery unit 10 (more specifically, the plus terminal of the first storage battery module 11), and the minus terminal (more specifically, of the storage battery unit 10). Is the negative terminal of the third storage battery module 13 and the negative terminal of the bidirectional converter 41 are connected to form a current path. In addition, the storage battery unit 10 which concerns on the comparative example 1 may be another connection method, as long as it is connected in parallel. For example, the positive terminal of the bidirectional converter 41 and the positive terminal of each storage battery unit 10 (more specifically, the positive terminal of the first storage battery module 11, the positive terminal of the second storage battery module 12, the third terminal) via the circuit breaker 20. The negative terminal of the bidirectional converter 41 and the negative terminal of each storage battery unit 10 (more specifically, the negative terminal of the first storage battery module 11 and the negative terminal of the second storage battery module 12). , A negative terminal of the third storage battery module 13) may be connected.

In the storage battery unit 10, a positive terminal of the first storage battery module 11 that is a positive external terminal of the storage battery unit 10 and a positive terminal of the second storage battery module 12 are connected. The plus terminal of the second storage battery module 12 and the plus terminal of the third storage battery module 13 are connected. Accordingly, the positive wiring resistance increases in the order of the first storage battery module 11, the second storage battery module 12, and the third storage battery module 13.

On the other hand, the minus terminal of the third storage battery module 13 that is the minus external terminal of the storage battery unit 10 and the minus terminal of the second storage battery module 12 are connected. The minus terminal of the second storage battery module 12 and the minus terminal of the first storage battery module 11 are connected. Accordingly, the negative wiring resistance increases in the order of the third storage battery module 13, the second storage battery module 12, and the first storage battery module 11.

Thus, by making the internal connection order of the plurality of storage battery modules forming the storage battery unit 10 in the reverse order of plus and minus, the wiring resistance of the plurality of storage battery modules can be made uniform easily. Therefore, it becomes easy to equalize the current flowing through the plurality of storage battery modules and the battery life.

The circuit breaker 20 is inserted between the plus terminal of the bidirectional converter 41 and the plus terminal of the first storage battery module 11. The circuit breaker 20 uses a general circuit breaker. Any of a thermal type, a thermal-electromagnetic type, a complete electromagnetic type, and an electronic type may be used.

In this specification, an example using an electronic circuit breaker is assumed. An electronic circuit breaker has a trip coil, contacts, and ammeter. The ammeter measures the value of the current flowing through the wiring and outputs it to the control device 30. The control device 30 controls energization of the trip coil based on the current value acquired from the ammeter. When an overcurrent flows through the wiring, the control device 30 energizes the trip coil to excite the trip coil. The contact forms an opening / closing part, and the opening / closing part opens when the trip coil is excited to interrupt the circuit.

Many electronic circuit breakers include two switching units for plus wiring and minus wiring, but in the power storage system 100 in this specification, the minus wiring is configured not to pass the circuit breaker 20. That is, the opening / closing part for minus wiring is not used. In FIG. 1, only the first opening / closing part 21 for plus wiring is drawn, and the opening / closing part for minus wiring is omitted. The same applies to FIG.

The control device 30 is a device for managing the storage battery unit 10. The control device 30 is connected to the monitoring unit in each storage battery module and the control unit 42 in the charging / discharging device 40 by a communication line. An RS-485 cable, an RS-422 cable, or the like can be used for the communication line. The control device 30 acquires monitoring data transmitted from the first monitoring unit 11 a of the first storage battery module 11, the second monitoring unit 12 a of the second storage battery module 12, and the third monitoring unit 13 a of the third storage battery module 13. When the acquired monitoring data is abnormal (for example, temperature abnormality), the control device 30 energizes the trip coil to open the first opening / closing part 21.

Further, the control device 30 transfers the monitoring data acquired from the monitoring unit to the control unit 42 of the charge / discharge device 40. The control device 30 may generate an instruction signal based on the monitoring data acquired from the monitoring unit, and transmit the generated instruction signal to the control unit 42. For example, when it is determined that the acquired monitoring data is abnormal, a charge stop / discharge stop instruction may be generated and transmitted to the control unit 42.

The charging / discharging device 40 is a device that causes the storage battery unit 10 to be charged from the outside or discharged from the storage battery unit 10 to the outside. At the time of charging, the bidirectional converter 41 of the charging / discharging device 40 performs DC-DC conversion on the direct-current power supplied from the outside in accordance with control by the control unit 42 and supplies it to the storage battery unit 10. Examples of DC power supplied from the outside include DC power generated by an AC-DC converter connected to a commercial system, and DC power generated by a solar cell or other generator.

During discharging, the bidirectional converter 41 converts the DC power supplied from the storage battery unit 10 into DC-DC under the control of the control unit 42 and supplies it to the outside. The DC power supplied to the outside is converted into AC power by an AC-DC converter and supplied to a load or is reversely flowed to the system. The DC power may be supplied to the DC load as it is.

When charging the storage battery unit 10 in which a lithium ion battery is used, the control unit 42 performs a constant current charge (CC charge) up to a predetermined set voltage, and bidirectionally performs a constant voltage charge (CV charge) when the set voltage is reached. The converter 41 is controlled. Specifically, the duty ratio of the switching element included in the bidirectional converter 41 is adjusted so that the output current value or the output voltage value of the bidirectional converter 41 is kept constant.

As shown in FIG. 1, in the storage battery unit 10 in which a plurality of storage battery modules are connected in parallel, the value of the short-circuit current that flows when the current path is short-circuited becomes large. As shown in FIG. 1, when the current is interrupted by one switching part, it is necessary to increase the rated breaking capacity. For example, when the short-circuit current of one storage battery module is about 1.9 kA, there is a possibility that a short-circuit current of about 5.7 kA, which is the sum of the short-circuit currents of three storage battery modules, flows in the current path. For this reason, a circuit breaker having an opening / closing part with a rated breaking capacity of 6.0 kA is sufficient. However, a circuit breaker having a large current breaking capacity is expensive. Therefore, it is conceivable to use a circuit breaker 20 having a multipolar structure having a plurality of switching parts.

FIG. 2 is a diagram illustrating a configuration of the power storage system 100 according to the second comparative example. The storage battery unit 10 according to the comparative example 2 is formed by connecting five storage battery modules of the first storage battery module 11, the second storage battery module 12, the third storage battery module 13, the fourth storage battery module 14, and the fifth storage battery module 15 in parallel. Is done. The circuit breaker 20 according to Comparative Example 2 is a five-pole circuit breaker including a first opening / closing part 21, a second opening / closing part 22, a third opening / closing part 23, a fourth opening / closing part 24, and a fifth opening / closing part 25.

In Comparative Example 2, in order to ensure the breaking capacity of the circuit breaker 20, the storage battery module and the opening / closing part are associated with each other at 1: 1. That is, the wiring extending from the plus terminal of the bidirectional converter 41 is branched into five and is connected to one end of the first opening / closing part 21, the second opening / closing part 22, the third opening / closing part 23, the fourth opening / closing part 24, and the fifth opening / closing part 25, respectively. Connecting. The wirings extending from the other ends of the first opening / closing part 21, the second opening / closing part 22, the third opening / closing part 23, the fourth opening / closing part 24 and the fifth opening / closing part 25 are the first storage battery module 11 and the second storage battery module 12. The third storage battery module 13, the fourth storage battery module 14, and the fifth storage battery module 15 are connected to the plus terminals.

In the circuit configuration in which the storage battery module and the open / close unit are associated with each other as shown in FIG. 2, the rated breaking capacity of each open / close unit can be suppressed. For example, when the short-circuit current of one storage battery module is about 1.9 kA, a circuit breaker having a switching unit with a rated breaking capacity of 2.5 kA is sufficient. However, when the number of opening / closing parts increases, the size of the circuit breaker increases and the cost also increases.

FIG. 3 is a diagram showing a configuration example of the power storage system 100 according to the embodiment of the present invention. In the embodiment, a plurality of storage battery modules forming the storage battery unit 10 are divided into a plurality of groups. In the example shown in FIG. 3, among the five storage battery modules of the first storage battery module 11, the second storage battery module 12, the third storage battery module 13, the fourth storage battery module 14, and the fifth storage battery module 15, the first storage battery module 11, The second storage battery module 12 and the third storage battery module 13 are set as the first group, and the fourth storage battery module 14 and the fifth storage battery module 15 are set as the second group.

The current paths of storage battery modules belonging to each group are connected in parallel. In the circuit configuration shown in FIG. 3, the bidirectional converter 41, the first storage battery module 11, the second storage battery module 12, and the third storage battery module 13 are referred to as a current path (hereinafter referred to as a first group current path), a bidirectional converter 41, Current paths (hereinafter referred to as second group current paths) are formed by the fourth storage battery module 14 and the fifth storage battery module 15, respectively. The first group current path and the second group current path are coupled together in parallel and connected to the bidirectional converter 41.

In the embodiment, the circuit breaker 20 having the number of switching units corresponding to the number of groups is used. In the example shown in FIG. 3, the circuit breaker 20 has a two-pole structure including a first opening / closing part 21 and a second opening / closing part 22. The first opening / closing part 21 is inserted into the first group current path. More specifically, it is inserted between the plus terminal of bidirectional converter 41 and the plus terminal of first storage battery module 11 that is the plus external terminal of the first group. The second opening / closing part 22 is inserted into the second group current path. More specifically, it is inserted between the plus terminal of bidirectional converter 41 and the plus terminal of fourth storage battery module 14 which is the plus external terminal of the second group.

When the circuit breaker 20 is opened due to an overcurrent exceeding a rated current among a plurality of switching parts, the remaining switching parts are also opened in conjunction. For example, a short-circuit current flows in the first group current path and the first opening / closing part 21 opens, and at the same time, the second opening / closing part 22 opens. Even when no overcurrent flows in the second group current path, the second group current path is interrupted. If the second opening / closing part 22 is kept closed when the first opening / closing part 21 is opened, the current flowing in the first group current path and the current flowing in the current path in the second group will flow into the second group of storage battery modules. This increases the possibility that the second group of storage battery modules will exceed the rated capacity.

Therefore, it is necessary to design the plurality of switching parts included in the circuit breaker 20 so that the switching is interlocked. For example, the handle switches of the respective opening / closing sections may be connected by a physical bar so that the opening / closing of the plurality of opening / closing sections is interlocked. The design in which the plurality of opening / closing parts are physically connected can be more reliably linked to the opening / closing of the plurality of opening / closing parts without time lag than the design in which the opening / closing of the plurality of opening / closing parts is interlocked only by electromagnetic induction.

Further, not only when the overcurrent is detected by the ammeter in the circuit breaker 20, but also when the circuit is interrupted based on the data abnormality acquired from the monitoring unit in the storage battery module, the control device 30 collects a plurality of switching units at once. And open. In this case as well, if only some of the open / close parts are opened, the current concentrates on the storage battery modules of the group connected to the open / closed parts that are closed, and there is a high possibility that the storage battery modules of that group will exceed the rated capacity. Become.

The rated breaking capacities of the plurality of switching units included in the circuit breaker 20 are individually designed according to the total rated capacity of at least one storage battery module connected in parallel to each group current path. Hereinafter, the voltage is assumed to be a constant voltage, and the rated capacity is considered as the rated current. For example, if the rated current of one storage battery module is 25A, the rated current of the first opening / closing part 21 can be designed to be 75A and the rated current of the second opening / closing part 22 can be designed to be 50A. In addition, depending on the number of storage battery modules, the rated breaking capacities of the plurality of switching units may be designed to be the same value.

FIG. 4 is a diagram showing another configuration example of the power storage system 100 according to the embodiment of the present invention. In the example illustrated in FIG. 4, the five storage battery modules of the first storage battery module 11, the second storage battery module 12, the third storage battery module 13, the fourth storage battery module 14, and the fifth storage battery module 15 are divided into three groups. The first group includes the first storage battery module 11, the second group includes the second storage battery module 12, and the third group includes the third storage battery module 13, the fourth storage battery module 14, and the fifth storage battery module 15.

In the embodiment, the circuit breaker 20 having the number of switching units corresponding to the number of groups is used. In the example shown in FIG. 4, the circuit breaker 20 has a three-pole structure including a first opening / closing part 21, a second opening / closing part 22, and a third opening / closing part 23. The first opening / closing part 21 is inserted into the first group current path. The second opening / closing part 22 is inserted into the second group current path. The third opening / closing part 23 is inserted in the third group current path. Assuming that the rated current of one storage battery module is 25A, the rated current of the first switching part 21 can be designed to be 25A, the rated current of the second switching part 22 can be designed to be 25A, and the rated current of the third switching part 23 can be designed to be 75A.

In the circuit configuration shown in FIG. 4, an example using a metal bus bar is illustrated. When there is a variation in the voltage difference between a plurality of storage batteries connected in parallel, a large current may flow from a storage battery having a high voltage to a storage battery having a low voltage, causing deterioration of the storage battery. Therefore, in order to suppress variations in the voltage between the parallel storage batteries, it is necessary to use wiring that matches the amount of voltage drop between the positive terminal and the negative terminal of the bidirectional converter 41. The first metal bus bar 51 is a metal bus bar for branching the wiring extending from the plus terminal of the bidirectional converter 41 into three branches. The resistance value of the wiring connecting the plus terminal of the bidirectional converter 41 and the first metal bus bar 51 is a value considering five times the resistance value of the wiring connecting to the terminal of one storage battery module (hereinafter referred to as a unit wiring resistance value). It is desirable to do. The resistance value of the wiring connecting the first metal bus bar 51 and the first opening / closing part 21 and the wiring connecting the first metal bus bar 51 and the second opening / closing part 22 are the same as the unit wiring resistance value. The resistance value of the wiring connecting the first metal bus bar 51 and the third opening / closing part 23 needs to be a value considering three times the unit wiring resistance value.

The resistance value of the wiring connecting the first opening / closing part 21 and the positive terminal of the first storage battery module 11 and the wiring connecting the second opening / closing part 22 and the positive terminal of the second storage battery module 12 are the same as the unit wiring resistance value. The second metal bus bar 52 is a metal bus bar for branching the wiring extending from the third opening / closing part 23 to the third group of storage battery modules into three branches. The resistance value of the wiring connecting the third opening / closing part 23 and the second metal bus bar 52 needs to be a value considering three times the unit wiring resistance value. Wiring connecting the second metal bus bar 52 and the positive terminal of the third storage battery module 13, wiring connecting the second metal bus bar 52 and the positive terminal of the fourth storage battery module 14, and the plus of the second metal bus bar 52 and the fifth storage battery module 15 The resistance value of the wiring connecting the terminals is a unit wiring resistance value.

The third metal bus bar 53 is a metal bus bar for branching the wiring extending from the negative terminal of the bidirectional converter 41 into five branches. The resistance value of the wiring connecting the minus terminal of the bidirectional converter 41 and the third metal bus bar 53 is preferably a value that takes into account five times the unit wiring resistance value. A wiring connecting the third metal bus bar 53 and the negative terminal of the first storage battery module 11, a wiring connecting the third metal bus bar 53 and the negative terminal of the second storage battery module 12, and a negative terminal of the third metal bus bar 53 and the third storage battery module 13 The resistance value of the wiring connecting the third metal bus bar 53 and the negative terminal of the fourth storage battery module 14 and the wiring connecting the third metal bus bar 53 and the negative terminal of the fifth storage battery module 15 are unit wiring resistance values. is there.

It is desirable that the wiring resistances connecting the storage battery modules and the bidirectional converter 41 are designed to be equal. Thus, by matching the resistance value of the wiring connecting each storage battery module and the bidirectional converter 41, it is possible to suppress variations in the voltage difference between the parallel storage batteries. Further, by using the metal bus bar, the wiring length of the entire power storage system 100 can be shortened, and the wiring route can be simplified. In addition, as demonstrated in FIG. 1, you may match | combine the wiring length of each storage battery module by making the connection order of the storage battery modules connected in parallel opposite on the plus side and the minus side.

The circuit breaker 20 shown in FIG. 4 is a general-purpose high circuit breaker that can correspond to any configuration of 1 to 5 parallel storage battery modules. FIG. 5 is a table that describes the number of parallel storage battery units 10 and the relationship between the open / close units to be used. When the storage battery unit 10 is formed of one storage battery module, the first opening / closing part 21 is used. The second opening / closing part 22 may be used. When the storage battery unit 10 is formed by parallel connection of two storage battery modules, the first opening / closing part 21 and the second opening / closing part 22 are used. When the storage battery unit 10 is formed by parallel connection of three storage battery modules, the third opening / closing part 23 is used. When the storage battery unit 10 is formed by parallel connection of four storage battery modules, the first opening / closing part 21 and the third opening / closing part 23 are used. The second opening / closing part 22 and the third opening / closing part 23 may be used. When the storage battery unit 10 is formed by parallel connection of five storage battery modules, all of the first opening / closing part 21, the second opening / closing part 22, and the third opening / closing part 23 are used. As described above, the circuit breaker 20 shown in FIG. 4 is highly versatile and can easily cope with the increase / decrease of the storage battery module within the range of the current interruption capacity. Moreover, since the circuit breaker 20 can respond | correspond to the various group structure of the storage battery module which a user desires, convenience improves.

FIG. 6 is a diagram showing a modification of the power storage system 100 of FIG. The power storage system 100 according to the modification has a configuration in which a fuse 54 is added to the power storage system 100 of FIG. The fuse 54 is inserted between the third opening / closing part 23 and the second metal bus bar 52 in order to supplement the current interruption capacity of the third opening / closing part 23. In addition to the group current path between the storage battery module and the switching unit, the fuse is connected between the positive terminal of the bidirectional converter 41 and the switching unit, the negative terminal of the bidirectional converter 41, and the negative terminal of the storage battery module. It may also be inserted between. The switching unit provided in the group current path in which the fuse is inserted can reduce the current interrupting capacity if the inserted fuse has the current interrupting capacity. Moreover, the current interruption capacity of the switching part can be lowered by using a high-resistance wiring.

As described above, according to the embodiment of the present invention, the plurality of storage battery modules forming the storage battery unit 10 are divided into a plurality of groups, and the circuit is cut off in units of groups. Thereby, the overcurrent protection in the power storage system can be constructed at low cost while maintaining the performance. That is, the rated breaking capacity of each opening / closing part can be made lower than the configuration in which the circuit is cut off by one opening / closing part. Moreover, the number of opening / closing parts can be reduced from the structure which provides an opening / closing part for every storage battery module. Moreover, the rated breaking capacity of each opening / closing part can be optimized according to the rated capacity of the storage battery modules of each group. Therefore, a necessary and sufficient overcurrent protection circuit can be constructed while suppressing an increase in the cost and size of the circuit breaker. Moreover, it can avoid that an electric current concentrates on the storage battery module of a specific group by interlocking opening and closing of a some opening-and-closing part. Since the necessary overcurrent protection can be realized at a low cost in this way, it is optimal for a power storage system using an expensive lithium ion battery through which a relatively large current flows.

The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. is there.

The invention according to the present embodiment may be specified by the items described below.

[Item 1]
A plurality of storage battery modules connected in parallel;
A circuit breaker inserted in a current path connecting the plurality of storage battery modules and a charge / discharge device that charges and discharges the plurality of storage battery modules;
The plurality of storage battery modules are divided into a plurality of groups,
A plurality of group current paths are formed by connecting the current paths of the storage battery modules belonging to each group in parallel to one another, and a plurality of group current paths are connected in parallel to one another and connected to the charge / discharge device,
The circuit breaker includes a plurality of switching units inserted into each of the plurality of group current paths,
The power storage system according to claim 1, wherein when one of the plurality of opening / closing parts is opened, the remaining opening / closing parts are also opened.

[Item 2]
The power storage system according to item 1, wherein the plurality of opening / closing sections are physically connected so that opening / closing is interlocked.

[Item 3]
Item 3. The power storage system according to item 1 or 2, wherein each rated breaking capacity of the plurality of switching units is individually designed according to the number of storage battery modules connected in parallel to each group current path.

[Item 4]
The electrical storage according to any one of items 1 to 3, further comprising a fuse that is inserted into a group current path between the storage battery module and the switching unit to supplement a current interrupting capacity of the switching unit. system.

[Item 5]
The storage battery module is
A plurality of storage battery cells;
A monitoring unit that monitors the state of the plurality of storage battery cells,
The power storage system includes:
5. The power storage system according to any one of items 1 to 4, further comprising a control device that collectively opens the plurality of opening / closing sections when data acquired from the monitoring section is abnormal.

100 power storage system, 10 storage battery unit, 11 first storage battery module, 11a first monitoring unit, 12 second storage battery module, 12a second monitoring unit, 13 third storage battery module, 13a third monitoring unit, 14 fourth storage battery module, 14a 4th monitoring unit, 15 5th storage battery module, 15a 5th monitoring unit, 20 circuit breaker, 21 1st switching unit, 22 2nd switching unit, 23 3rd switching unit, 24 4th switching unit, 25 5th switching Part, 30 control device, 40 charge / discharge device, 41 bidirectional converter, 42 control unit, 51 first metal bus bar, 52 second metal bus bar, 53 third metal bus bar, 54 fuse.

The present invention can be used in a power storage system including a storage battery unit in which a plurality of storage battery modules are connected in parallel.

Claims (5)

A plurality of storage battery modules connected in parallel;
A circuit breaker inserted in a current path connecting the plurality of storage battery modules and a charge / discharge device that charges and discharges the plurality of storage battery modules;
The plurality of storage battery modules are divided into a plurality of groups,
A plurality of group current paths are formed by connecting the current paths of the storage battery modules belonging to each group in parallel to one another, and a plurality of group current paths are connected in parallel to one another and connected to the charge / discharge device,
The circuit breaker includes a plurality of switching units inserted into each of the plurality of group current paths,
The power storage system according to claim 1, wherein when one of the plurality of opening / closing parts is opened, the remaining opening / closing parts are also opened. The power storage system according to claim 1, wherein the plurality of opening / closing sections are physically connected so that the opening / closing is interlocked. The power storage system according to claim 1 or 2, wherein each rated breaking capacity of the plurality of switching units is individually designed according to the number of storage battery modules connected in parallel to each group current path. 4. The fuse according to claim 1, further comprising a fuse that is inserted into a group current path between the storage battery module and the opening / closing part to supplement a current interruption capacity of the opening / closing part. Power storage system. The storage battery module is
A plurality of storage battery cells;
A monitoring unit that monitors the state of the plurality of storage battery cells,
The power storage system includes:
5. The power storage system according to claim 1, further comprising a control device that collectively opens the plurality of opening and closing units when data acquired from the monitoring unit is abnormal.

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