Power storage facilities, determination device, and computer program

Abstract

To provide power storage facilities, a determination device, and a computer program.SOLUTION: Power storage facilities include a plurality of power storage elements connected in parallel, and a connection circuit that connects the plurality of power storage elements to an external current supply source or a current supply destination. The connection circuit includes: a first current path connected to the current supply source or the current supply destination; a plurality of second current paths branched from the first current path and respectively connected to the plurality of power storage elements; a first current sensor that measures a current flowing through the first current path; and a plurality of second current sensors that individually measure a current flowing through each of the plurality of second current paths. The power storage facilities include a determination unit that determines presence or absence of abnormality in the connection circuit using measurement results of the first current sensor and measurement results of the plurality of second current sensors.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a power storage device, a determination device, and a computer program.

Background Art

[0002] Power storage devices that store electric power supplied from power generation facilities such as solar power generation facilities and wind power generation facilities and supply the stored electric power to loads such as factories and office buildings as needed are widespread. The power storage device is equipped with a large number of power storage elements (power storage modules or banks).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, when an abnormality occurs in a power storage device equipped with a large number of power storage elements, it has not been easy to identify the abnormal location.

[0005] An object of the present disclosure is to provide a power storage device, a determination device, and a computer program capable of determining an abnormality in a connection circuit that connects a power storage element to a current supply source or a current supply destination.

Means for Solving the Problems

[0006] The power storage equipment of the present disclosure includes a plurality of power storage elements connected in parallel, and a connection circuit that connects the plurality of power storage elements to an external current supply source or a current supply destination. The connection circuit includes a first current path connected to the current supply source or the current supply destination, a plurality of second current paths branched from the first current path and respectively connected to the plurality of power storage elements, a first current sensor that measures the current flowing through the first current path, and a plurality of second current sensors that individually measure the currents flowing through the plurality of second current paths. The power storage equipment includes a determination unit that determines the presence or absence of an abnormality in the connection circuit using the measurement result of the first current sensor and the measurement results of the plurality of second current sensors.

Advantages of the Invention

[0007] In the present disclosure, it is possible to determine an abnormality in the connection circuit that connects the power storage element to the current supply source or the current supply destination.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] (1) The power storage facility of the present disclosure includes a plurality of power storage elements connected in parallel and a connection circuit that connects the plurality of power storage elements to an external current supply source or current supply destination. The connection circuit includes a first current path connected to the current supply source or the current supply destination, a plurality of second current paths branched from the first current path and respectively connected to the plurality of power storage elements, a first current sensor that measures the current flowing through the first current path, and a plurality of second current sensors that individually measure the current flowing through each of the plurality of second current paths. The power storage facility includes a determination unit that determines the presence or absence of an abnormality in the connection circuit using the measurement result of the first current sensor and the measurement results of the plurality of second current sensors.

[0010] The power storage facility is installed in parallel with power generation facilities such as solar power generation facilities and wind power generation facilities, stores the power supplied from the power generation facilities, and supplies the stored power to a load. An example of the power storage facility is an ESS (Energy Storage System). Alternatively, the power storage facility may be a power conditioner, a backup power supply device, or the like.

[0011] The power storage facility includes a plurality of power storage elements connected in parallel. The power storage element is, for example, a module configured by connecting a plurality of storage cells in series, or a bank configured by connecting a plurality of modules in series. In the following embodiments, the configuration of a power storage facility including a plurality of banks will be described.

[0012] In a power storage facility having a plurality of banks, it is important to be able to correctly measure the current of each bank. The accuracy of determination and estimation in the operating state, deterioration state, and expected life of the power storage facility is affected by the accuracy of current measurement of each bank. The power storage facility, which is a social infrastructure, is desirably operated constantly. It is necessary to prevent a situation where, due to improper current measurement, it is erroneously determined that an abnormality has occurred in a bank when there is actually no problem with the bank, leading to the stoppage of operation of the power storage facility.

[0013] Since power storage equipment such as an ESS has a large number of banks, the number of current sensors provided for each bank is also large, and the possibility of an abnormality occurring in the current sensors is relatively high in such equipment.

[0014] In the power storage equipment of (1) above, using the measurement result of the first current sensor that measures the current flowing through the first current path and the measurement results of a plurality of second current sensors that individually measure the currents flowing through the plurality of second current paths, it is possible to determine whether there is an abnormality in the connection circuit, and thus it is possible to distinguish whether there is an abnormality in the current path or in the current sensor. Here, an abnormality in the current path means a state in which the resistance of the current path becomes high due to some cause and the current of the magnitude that should originally flow through the current path does not flow. An abnormality in the current sensor means a state in which the current sensor does not show the current value that it should originally indicate.

[0015] With the configuration of (1) above, even when the current measurement value shows an abnormal value, it is possible to determine the cause and suppress the operation stop of the power storage equipment due to an incorrect judgment.

[0016] (2) In the power storage equipment described in (1) above, the determination unit may compare the current value indicating the magnitude of the current measured by the first current sensor with the total value indicating the sum of the magnitudes of the individual currents measured by the plurality of second current sensors, compare the ratio of the individual internal resistance values of the plurality of power storage elements with the ratio of the magnitudes of the individual currents measured by the plurality of second current sensors, and determine whether there is an abnormality in the connection circuit according to the comparison result between the current value and the total value, and the comparison result between the ratio of the internal resistance values and the ratio of the magnitudes of the currents.

[0017] According to the power storage equipment of (2) above, according to the comparison result between the current value of the current measured by the first current sensor and the total value of the currents measured by the second current sensors, and the comparison result between the ratio of the internal resistance values and the ratio of the magnitudes of the currents flowing through the respective power storage elements, it is possible to determine whether there is an abnormality in the connection circuit including the first current path, the plurality of second current paths, the first current sensor, and the plurality of second current sensors.

[0018] (3) In the power storage equipment according to the above (1) or (2), when the determination unit determines that the current value is different from the total value and the ratio of the internal resistance values is substantially equal to the ratio of the magnitudes of the currents, the determination unit may determine that there is an abnormality in the first current sensor.

[0019] The power storage equipment according to the above (3) compares the ratio of the internal resistance values with the ratio of the magnitudes of the currents flowing through each power storage element. When it is determined that both are substantially equal, it can be determined that there is no abnormality in the second current sensor that measures the current flowing through each power storage element. Furthermore, when the current value of the current measured by the first current sensor is different from the total value of the currents measured by the second current sensor, the power storage equipment can determine that there is an abnormality in the first current sensor. Here, the fact that the ratio of the internal resistance values is substantially equal to the ratio of the magnitudes of the currents means that it includes both the case where both are exactly equal and the case where both deviate within the allowable error range from the case where both are exactly equal.

[0020] (4) In the power storage equipment according to any one of the above (1) to (3), when the determination unit determines that the current value is different from the total value and the ratio of the internal resistance values is different from the ratio of the magnitudes of the currents, the determination unit may determine that there is an abnormality in at least one of the second current sensors.

[0021] When the ratio of the internal resistance values is different from the ratio of the magnitudes of the currents flowing through each power storage element, there are both possibilities of an abnormality in any of the second current sensors and a possibility of an abnormality in the second current path. Furthermore, when the current value of the current measured by the first current sensor is different from the total value of the currents measured by the second current sensor, it means that at least one of the second current sensors did not show the current value that it should originally show. Therefore, the power storage equipment can determine that there is an abnormality in at least one of the second current sensors.

[0022] (5) In the power storage equipment according to any one of the above (1) to (4), when the determination unit determines that the current value is substantially equal to the total value and the ratio of the internal resistance values is different from the ratio of the magnitudes of the currents, the determination unit may determine that there is an abnormality in at least one of the second current paths.

[0023] When the ratio of the internal resistance values and the ratio of the magnitudes of the currents flowing through the respective power storage elements are different, there is a possibility of an abnormality in either of the second current sensors and a possibility of an abnormality in the second current path. Moreover, when the current value of the current measured by the first current sensor and the total value of the currents measured by the second current sensors are substantially equal, it means that there is no abnormality in the first current sensor and the second current sensors, so the power storage facility can determine that there is an abnormality in at least one of the second current paths. Here, the fact that the current value of the current measured by the first current sensor and the total value of the currents measured by the second current sensors are substantially equal means that it includes both the case where the two are exactly equal and the case where they deviate within the allowable error range from the case where the two are exactly equal.

[0024] (6) In the power storage facility according to any one of (1) to (5) above, when the current value and the total value are substantially equal and the ratio of the internal resistance values and the ratio of the magnitudes of the currents are substantially equal, the determination unit may determine that there is no abnormality in the connection circuit.

[0025] In the power storage facility of (6) above, when the current value of the current measured by the first current sensor and the total value of the currents measured by the second current sensors are substantially equal, and the ratio of the internal resistance values and the ratio of the magnitudes of the currents flowing through the respective power storage elements are substantially equal, it can be determined that there is no abnormality in the first current path, the plurality of second current paths, the first current sensor, and the plurality of second current sensors.

[0026] (7) In the power storage facility according to any one of (1) to (6) above, the power storage element is a module formed by connecting a plurality of power storage cells in series, or a bank formed by connecting a plurality of such modules in series.

[0027] According to the power storage facility of (7) above, it is possible to avoid erroneously determining that there is an abnormality in the module or the bank in a situation where there is actually no problem in the module or the bank due to improper current measurement.

[0028] (8) The determination device of the present disclosure includes a connection circuit including a plurality of energy storage elements connected in parallel, a first current path connected to an external current supply source or a current supply destination, a plurality of second current paths branched from the first current path and respectively connected to the plurality of energy storage elements, a first current sensor that measures the current flowing through the first current path, and a plurality of second current sensors that individually measure the current flowing through each of the plurality of second current paths. An acquisition unit that acquires the measurement result of the first current sensor and the measurement results of the plurality of second current sensors from the power storage facility, and a determination unit that determines the presence or absence of an abnormality in the connection circuit using the acquired measurement result of the first current sensor and the measurement results of the plurality of second current sensors.

[0029] According to the determination device in (8) above, even when the current measurement value indicates an abnormal value, it is possible to discriminate the cause and suppress the operation stop of the power storage facility due to an incorrect determination.

[0030] (9) The computer program of the present disclosure acquires the measurement result of the first current sensor and the measurement results of the plurality of second current sensors from a power storage facility including a connection circuit including a plurality of energy storage elements connected in parallel, a first current path connected to an external current supply source or a current supply destination, a plurality of second current paths branched from the first current path and respectively connected to the plurality of energy storage elements, a first current sensor that measures the current flowing through the first current path, and a plurality of second current sensors that individually measure the current flowing through each of the plurality of second current paths. It is a computer program for causing a computer to execute a process of determining the presence or absence of an abnormality in the connection circuit using the acquired measurement result of the first current sensor and the measurement results of the plurality of second current sensors.

[0031] According to the computer program in (9) above, even when the current measurement value indicates an abnormal value, it is possible to discriminate the cause and suppress the operation stop of the power storage facility due to an incorrect determination.

[0032] Hereinafter, the present invention will be specifically described based on the drawings showing its embodiments. (Embodiment 1) FIG. 1 is a schematic diagram showing the overall configuration of an energy storage system including an energy storage device (an example of an energy storage facility). The energy storage system according to the embodiment includes an energy storage device 1, a power generation facility 2, and a load 3. The energy storage device 1 is, for example, an ESS, stores the power supplied from the power generation facility 2, and supplies the stored power to the load 3. The power generation facility 2 includes a solar power generation facility 21, a wind power generation facility 22, and the like. The load 3 includes power consumption facilities such as factories, office buildings, schools, hospitals, restaurants, and airports.

[0033] A power converter 20 is installed between the energy storage device 1, the power generation facility 2, and the load 3. The power converter 20 is also called a PCS (Power Conditioning System). The power converter 20 converts the power (alternating current power or direct current power) supplied from the power generation facility 2 into direct current power of a predetermined magnitude, and supplies the converted direct current power to the energy storage device 1. The energy storage device 11 stores the power supplied from the power generation facility 2 via the power converter 20.

[0034] The energy storage device 11 supplies the stored power to the load 3 in response to a request from the outside. The power supplied from the energy storage device 11 to the load 3 is converted from direct current power to alternating current power by the power converter 20.

[0035] Alternatively, the energy storage device 11 may store the power supplied from the power grid 4, and may supply the stored power to the power grid 4.

[0036] The energy storage system includes a monitoring server 5 that remotely monitors the energy storage device 1. The energy storage device 1 and the monitoring server 5 are communicably connected via a communication network NW. The communication network NW may be a general line such as the Internet, or may be a dedicated line. The energy storage device 1 transmits and receives information to and from the monitoring server 5 via the communication network NW.

[0037] FIG. 2 is a schematic diagram showing the internal configuration of the battery facility 1. The battery facility 1 includes a container body 10 (see FIG. 1), a battery board 11, and a control board 12 housed in the container body 10. FIG. 2 shows a configuration example of the battery board 11 and the control board 12 housed in the container body 10. The number of battery boards 11 included in the battery facility 1 may be two or more. In addition to the battery board 11 and the control board 12, the container body 10 may house auxiliary equipment such as an air conditioner and a lighting device.

[0038] The battery board 11 includes a plurality of banks 111 and a management unit 112. Each bank 111 is configured by electrically connecting a plurality of battery modules BT in series. In the example of FIG. 2, the battery board 11 includes three banks 111, and each bank 111 is configured by electrically connecting a total of 18 battery modules BT in two vertical rows in series. These three banks 111 are connected to each other in parallel. A configuration in which a plurality of banks 111 are connected in parallel is also called a domain. The number of banks 111 included in the battery board 11 and the number of battery modules BT constituting each bank 111 are arbitrarily selected.

[0039] The battery module BT is configured by connecting a plurality of battery cells in series. In one example, the battery cell is a battery cell using a lithium-ion secondary battery. Alternatively, the battery cell may be a battery cell using an all-solid-state battery, a lead battery, a redox flow battery, a zinc-air battery, an alkaline manganese battery, a lithium-sulfur battery, a sodium-sulfur battery, a silver-zinc oxide battery, a nickel-metal hydride battery, a molten salt thermal battery, etc., or may be a capacitor. The number of battery cells constituting the battery module BT is arbitrarily selected.

[0040] The management unit 112 is a device for monitoring the state of the bank 111. The management unit 112 is provided for each bank 111. In the example of FIG. 2, the management unit 112 is provided above each bank 111. Hereinafter, the management unit 112 provided in the battery pack 11 is referred to as a bank BMU (Battery Management Unit) 112. The bank BMU 112 monitors the state of the corresponding bank 111 and notifies the obtained information of the bank 111 to a higher-level management unit (the domain BMU 121 shown in FIG. 3).

[0041] Hereinafter, a configuration in which the battery facility 1 includes one battery pack 11 and the battery pack 11 includes three banks 111 will be described as an example.

[0042] FIG. 3 is an explanatory diagram for explaining the circuit configuration of the battery facility 1. The battery pack 11 of the battery facility 1 includes, as described above, three banks 111 and three bank BMUs 112 provided corresponding to each bank 111. The control panel 12 of the battery facility 1 includes a domain BMU 121 and a communication interface 122. The bank BMU 112 and the domain BMU 121 are communicably connected. Existing communication standards such as CAN (Controller Area Network) are used for communication between the bank BMU 112 and the domain BMU 121. Alternatively, communication standards such as LIN (Local Interconnect Network), ECHONET (registered trademark), and ECHONETLight (registered trademark) may be used.

[0043] The bank 111 is connected to an external current supply source or current supply destination via the main circuit MC. The external current supply source is the power generation facility 2 (or the power grid 4), and the external current supply destination is the load 3 (or the power grid 4).

[0044] Hereinafter, when the three banks 111 are separately described, the bank 111 is also denoted as banks 111A, 111B, and 111C. Similarly, when the three bank BMUs 112 are separately described, the bank BMU 112 is also denoted as bank BMUs 112A, 112B, and 112C.

[0045] The main circuit MC includes one first current path P1 connected to a current supply source or a current supply destination, and three second current paths P2A to P2C branched from the first current path P1 and connected to each of the banks 111A to 111C. The main circuit MC further includes a first current sensor S1 that measures the current flowing through the first current path P1, and three second current sensors S2A to S2C that measure the currents flowing through the second current paths P2A to P2C, respectively. The first current sensor S1 and the second current sensors S2A to S2C are existing current sensors such as Hall sensors. The first current sensor S1 outputs the measurement result to the domain BMU121. The second current sensors S2A to S2C output the measurement results to the domain BMU121 through the respective banks BMU112A to 112C.

[0046] The domain BMU121 is a device for monitoring the state of the domain (the entire bank). The domain BMU121 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The CPU included in the domain BMU121 reads and executes the computer program stored in the ROM, thereby causing the domain BMU121 to function as the determination device of the present application. The RAM temporarily stores data generated during the execution of the computer program and data acquired from the outside.

[0047] In the embodiment, the domain BMU121 acquires the measurement result of the first current sensor S1 and the measurement results of the second current sensors S2A to S2C, and uses the acquired measurement result of the first current sensor S1 and the measurement results of the second current sensors S2 to determine whether there is an abnormality in the main circuit 120.

[0048] Domain BMU121 outputs the determination result of the presence or absence of an abnormality in the main circuit 120. For example, domain BMU121 notifies an external device through the communication interface 122. An example of the external device is the monitoring server 5 that monitors the state of the battery facility 1. The communication interface 122 of the battery facility 1 and the monitoring server 5 are communicably connected via a communication network NWA such as the Internet network. When the battery facility 1 is provided with a display unit such as a liquid crystal display, the determination result of the presence or absence of an abnormality in the main circuit 120 may be output to the display unit and displayed on the display unit.

[0049] Figure 4 is a flowchart for explaining the procedure of the process executed by the battery facility 1. In executing the following procedure, it is assumed that the internal resistances of each of the banks 111A to 111C have been measured in advance. The internal resistance is obtained by actually measuring the voltage of each of the banks 111A to 111C when performing a constant current discharge from each of the banks 111A to 111C. The voltages of each of the banks 111A to 111C are measured by a voltage sensor (not shown in the figure). When the current value when performing a constant current discharge from bank 111A is I (since a constant current discharge is being performed, I is known), and the voltage value of bank 111A is V (V is the actually measured value by the voltage sensor), the internal resistance R of bank 111A is obtained by R = V / I. The same applies to the internal resistances of the other banks 111B and 111C. The internal resistance values of banks 111A, 111B, and 111C (denoted as Ra, Rb, and Rc respectively) are obtained in advance, and each value is assumed to be stored in the memory inside domain BMU121.

[0050] When the battery facility 1 supplies power to the load 3, the battery facility 1 measures the current flowing through the first current path P1 with the first current sensor S1, and measures the currents flowing through each of the second current paths P2A to P2C with the second current sensors S2A to S2C respectively (step S101). The measurement result by the current sensor S1 is output to domain BMU121. The measurement results by the current sensors S2A to S2C are output to the bank BMUs 112A to 112C respectively.

[0051] Domain BMU121 acquires the measurement result by the first current sensor S1 and acquires the measurement results by the second current sensors S2A to S2C through the banks BMU112A to 112C (step S102). Let the current value obtained as the measurement result of the first current sensor S1 be I, and the current values obtained as the measurement results of the second current sensors S2A, S2B, and S2C be Ia, Ib, and Ic, respectively.

[0052] Domain BMU121 compares the current value measured by the first current sensor S1 with the sum of the current values Ia to Ic measured by the second current sensors S2A to S2C, and determines whether they are equal (step S103). That is, domain BMU121 determines whether I = Ia + Ib + Ic. They do not necessarily have to numerically match exactly, and the values may deviate within the allowable error range. In this case, when the allowable error is ε1, if the difference between the two is less than ε1, they are judged to be substantially equal. The allowable error ε1 is set as appropriate. For example, the allowable error ε1 may be set artificially. Alternatively, the difference in current values (=|I - (Ia + Ib + Ic)|) may be actually measured using a normal connection circuit MC, and the allowable error ε based on that difference may be set.

[0053] When it is determined that the total current values are equal (S103: YES), the domain BMU121 compares the ratio of the internal resistance values of each bank 111A to 111C (= Ra: Rb: Rc) with the ratio of the current values measured by the second current sensors S2A to S2C (= Ia: Ib: Ic), and determines whether or not they are equal (step S104). That is, the domain BMU121 determines whether Ra: Rb: Rc = Ia: Ib: Ic. They do not have to numerically match exactly, and the values may deviate within the range of allowable error. For example, when the allowable errors are ε2 and ε3, if |Ia / Ra - Ib / Rb| < ε2 and |Ia / Ra - Ic / Rc| < ε3, they are determined to be substantially equal. The allowable errors ε2 and ε3 are set as appropriate. For example, ε2 and ε3 may be set artificially. Alternatively, the ratio (Ia: Ib: Ic) may be actually measured using a normal connection circuit MC, and the allowable errors ε2 and ε3 based on that ratio may be set.

[0054] When the total current values are equal (S103: YES) and it is determined that the ratios are equal (S104: YES), the domain BMU121 determines that the current paths (the first current path P1 and the second current paths P2A to P2C) and the current sensors (the first current sensor S1 and the second current sensors S2A to S2C) in the connection circuit MC are normal (step S106).

[0055] When the total current values are equal (S103: YES) and it is determined that the ratios are different (S104: NO), the domain BMU121 determines that the first current sensor S1 and the second current sensors S2A to S2C are normal, and that there is an abnormality in any one of the second current paths P2A to P2C (step S107). When the domain BMU121 determines that there is an abnormality in any one of the second current paths P2A to P2C, it may identify which current path has the abnormality. In the embodiment, since the ratio of the internal resistance values is known, the domain BMU121 can identify the path in which the current assumed from the ratio of the internal resistance values is not flowing as the path with the abnormality.

[0056] If it is determined in step S103 that the total current value is different (S103: NO), the domain BMU121 compares the ratio of the internal resistance values of each bank 111A to 111C (= Ra: Rb: Rc) with the ratio of the current values measured by the second current sensors S2A to S2C (= Ia: Ib: Ic), and determines whether the two are equal (step S105). The determination method is the same as in step S104, and the domain BMU121 determines whether Ra: Rb: Rc = Ia: Ib: Ic. The two do not have to match numerically exactly, and the values may deviate within the allowable error range.

[0057] If the total current value is different (S103: NO) and it is determined that the ratios are equal (S105: YES), the domain BMU121 determines that the first current sensor S1 is abnormal (step S108).

[0058] If the total current value is different (S103: NO) and it is determined that the ratios are different (S105: NO), the domain BMU121 determines that any one of the second current sensors S2A to S2C is abnormal (step S109).

[0059] The domain BMU121 outputs the determination results of S106 to S109 (step S110). For example, the domain BMU121 notifies the monitoring server 5 of the determination results through the communication interface 122. When the control panel 12 includes a display unit such as a liquid crystal display, the domain BMU121 may display the determination results on the display unit.

[0060] As described above, in the first embodiment, by using the measurement results of the current flowing through the first current path P1 and the measurement results of the currents flowing through each of the second current paths P2A to P2C, it is possible to determine which of the first current path P1, the second current paths P2A to P2C, the first current sensor S1, and the second current sensors S2A to S2C that make up the main circuit MC is abnormal.

[0061] (Second Embodiment) In the second embodiment, a configuration in which the monitoring server 5 executes determination processing will be described. Since the overall configuration of the power storage system and the internal configuration of the battery facility 1 are the same as those in the first embodiment, the description thereof is omitted.

[0062] FIG. 5 is a block diagram for explaining the internal configuration of the monitoring server 5. The monitoring server 5 includes a control unit 51, a storage unit 52, a communication unit 53, an operation unit 54, a display unit 55, and the like.

[0063] The control unit 51 is, for example, an arithmetic circuit including a CPU, a ROM, a RAM, and the like. The CPU included in the control unit 51 reads and executes various computer programs stored in the ROM and the storage unit 52, and functions as a determination device for determining an abnormality in the main circuit MC in the battery facility 1. In the embodiment, the control unit 51 determines an abnormality in the main circuit MC based on the measurement results obtained from the battery facility 1.

[0064] Alternatively, the control unit 51 may be any arithmetic circuit including a plurality of CPUs, a multi-core CPU, a GPU (Graphics Processing Unit), a microcomputer, a volatile or non-volatile memory, and the like. The control unit 51 may have functions such as a timer for measuring the elapsed time from when a measurement start instruction is given to when a measurement end instruction is given, a counter for counting numbers, and a clock for outputting date and time information.

[0065] The storage unit 52 includes a storage device such as a flash memory and a hard disk. Various computer programs and data are stored in the storage unit 52. The computer programs stored in the storage unit 52 include a determination processing program PG for causing a computer to execute a process of determining an abnormality in the main circuit MC based on the measurement results acquired from the battery facility 1. The data stored in the storage unit 52 includes parameters used in the determination processing program PG and data generated by the control unit 51.

[0066] A computer program including a diagnostic program PG is provided by a non-transitory recording medium RM on which the computer program is readable. The recording medium RM is a portable memory such as a CD-ROM, a USB memory, an SD (Secure Digital) card, etc. The control unit 51 reads a desired computer program from the recording medium RM using a reading device (not shown in the figure) and stores the read computer program in the storage unit 52. Alternatively, a computer program including a determination processing program PG may be provided by communication.

[0067] The communication unit 53 includes a communication interface for transmitting and receiving various information. The communication unit 53 receives, for example, the measurement results of the first current sensor S1 and the second current sensors S2A to S2C transmitted by the battery facility 5.

[0068] The operation unit 54 includes input devices such as various switches and buttons, and receives operations by an administrator. The display unit 55 includes a display device such as a liquid crystal display device, and displays information to be notified to the administrator. Alternatively, the monitoring server 5 may be configured to receive necessary operations through an external computer and transmit information to be notified to the administrator to the external computer. In this case, the operation unit 54 and the display unit 55 do not have to be mounted on the monitoring server 5.

[0069] In the embodiment, the monitoring server 5 may be a single computer, or may be a computer system configured by a plurality of computers, peripheral devices, etc. The monitoring server 5 may be a virtual machine in which the entity is virtualized, or may be a cloud.

[0070] In the embodiment, the determination processing program PG may be a single computer program, or may be a program group composed of a plurality of computer programs. The determination processing program PG may be executed in cooperation by a plurality of computers.

[0071] FIG. 6 is a flowchart for explaining the procedure of the process executed by the monitoring server 5. In executing the following procedure, it is assumed that the internal resistances of the respective banks 111A to 111C have been measured in advance, and the measured values have been stored in the storage unit 52 of the monitoring server 5.

[0072] The control unit 51 of the monitoring server 5 acquires, through the communication unit 53, the measurement result by the first current sensor S1 and the measurement results by the second current sensors S2A to S2C from the storage battery facility 1 (step S201).

[0073] The control unit 51 determines an abnormality in the main circuit MC using the acquired measurement results. The determination procedure is the same as in the first embodiment. The control unit 51 compares the current value measured by the first current sensor S1 with the total value of the currents measured by the second current sensors S2A to S2C, and determines whether or not they are equal (step S202). The control unit 51 compares the ratio of the internal resistance values of the respective banks 111A to 111C with the ratio of the current values measured by the second current sensors S2A to S2C, and determines whether or not they are equal (steps S203 and S204).

[0074] When it is determined that the total values are equal and the ratios are equal (S202: YES, S203: YES), the control unit 51 determines that the main circuit MC is normal (step S205).

[0075] When it is determined that the total values are equal and the ratios are different (S202: YES, S203: NO), the control unit 51 determines that there is an abnormality in any one of the second current paths P2A to P2C (step S206).

[0076] When it is determined that the total values are different and the ratios are equal (S202: NO, S204: YES), the control unit 51 determines that there is an abnormality in the first current sensor S1 (step S207).

[0077] When the total values are different and the ratios are different (S202: NO, S204: NO), the control unit 51 determines that there is an abnormality in any one of the second current sensors S2A to S2C (step S208).

[0078] The control unit 51 outputs the determination results of S205 to S208 (step S209). For example, the control unit 51 may display the determination results on the display unit 55. Alternatively, the control unit 51 may notify the determination results to a terminal such as an administrator through the communication unit 53.

[0079] As described above, in the second embodiment, it is possible to determine whether there is an abnormality in any of the first current path P1, the second current paths P2A to P2C, the first current sensor S1, and the second current sensors S2A to S2C that constitute the main circuit MC of the battery facility 1 by the external monitoring server 5.

[0080] The disclosed embodiments are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims, and includes all modifications within the meaning and scope equivalent to the scope of the claims.

[0081] For example, in the embodiment, the battery facility 1 is configured to include one battery panel 11, and this battery panel 11 includes three banks 111. Alternatively, the battery facility 1 may be configured to include a plurality of battery panels 11, and each battery panel includes one or more banks 111.

[0082] In the embodiment, a configuration is adopted in which a power converter 20 is provided separately from the battery facility 1. Alternatively, the battery facility 1 may be configured to include the power converter 20.

Description of Reference Numerals

[0083] 1 Battery facility (power storage facility) 2 Power generation facility 3 Load 4 Power system 5 Monitoring server 11 Battery panel 12 Control panel 111 Bank 112 Bank BMU 121 Domain BMU 122 Communication interface MC Connection circuit P1 First current path P2A~P2C Second current paths S1 First current sensor S2A~S2C Second current sensors

Claims

1. A power storage facility comprising a plurality of power storage elements connected in parallel and a connection circuit for connecting the plurality of power storage elements to an external current supply source or current supply destination, wherein the connection circuit includes a first current path connected to the current supply source or the current supply destination, a plurality of second current paths branched from the first current path and respectively connected to the plurality of power storage elements, a first current sensor for measuring the current flowing through the first current path, and a plurality of second current sensors for individually measuring the current flowing through each of the plurality of second current paths, and a determination unit for determining the presence or absence of an abnormality in the connection circuit using the measurement result of the first current sensor and the measurement results of the plurality of second current sensors. A power storage facility comprising the same.

2. The determination unit compares a current value indicating the magnitude of the current measured by the first current sensor with a total value indicating the sum of the magnitudes of the individual currents measured by the plurality of second current sensors, compares the ratio of the individual internal resistance values of the plurality of power storage elements with the ratio of the magnitudes of the individual currents measured by the plurality of second current sensors, and determines the presence or absence of an abnormality in the connection circuit according to the comparison result between the current value and the total value and the comparison result between the ratio of the internal resistance values and the ratio of the magnitudes of the currents. The power storage facility according to claim 1.

3. The determination unit determines that there is an abnormality in the first current sensor when the current value and the total value are different and the ratio of the internal resistance values and the ratio of the magnitudes of the currents are substantially equal. The power storage facility according to claim 2.

4. The determination unit When the current value and the total value are different and the ratio of the internal resistance values and the ratio of the magnitudes of the currents are different, it is determined that there is an abnormality in at least one of the second current sensors. The power storage facility according to claim 2.

5. The determination unit When the current value and the total value are substantially equal and the ratio of the internal resistance values and the ratio of the magnitudes of the currents are different, it is determined that there is an abnormality in at least one of the second current paths. The power storage facility according to claim 2.

6. The determination unit When the current value and the total value are substantially equal and the ratio of the internal resistance values and the ratio of the magnitudes of the currents are substantially equal, it is determined that there is no abnormality in the connection circuit. The power storage facility according to claim 2.

7. The power storage element is a module formed by connecting a plurality of storage cells in series, or a bank formed by connecting a plurality of the modules in series. The power storage facility according to any one of claims 1 to 6.

8. A power storage facility including a plurality of power storage elements connected in parallel, a first current path connected to an external current supply source or a current supply destination, a plurality of second current paths branched from the first current path and respectively connected to the plurality of power storage elements, a first current sensor for measuring the current flowing through the first current path, and a plurality of second current sensors for individually measuring the currents flowing through the plurality of second current paths, an acquisition unit that acquires the measurement result of the first current sensor and the measurement results of the plurality of second current sensors, A determination unit that determines the presence or absence of an abnormality in the connection circuit using the acquired measurement result of the first current sensor and the measurement results of the plurality of second current sensors A determination device comprising:

9. A power storage facility including a connection circuit having a plurality of power storage elements connected in parallel, a first current path connected to an external current supply source or current supply destination, a plurality of second current paths branched from the first current path and respectively connected to the plurality of power storage elements, a first current sensor for measuring a current flowing through the first current path, and a plurality of second current sensors for individually measuring currents flowing through the plurality of second current paths, obtains a measurement result of the first current sensor and measurement results of the plurality of second current sensors. Determines the presence or absence of an abnormality in the connection circuit using the obtained measurement result of the first current sensor and the measurement results of the plurality of second current sensors. A computer program for causing a computer to execute the processing.

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