Battery control device and battery connection control device

Abstract

To ensure processing capacity even in a large-scale power storage system and achieve cooperative control between storage battery strings.SOLUTION: A system controller 101 acquires information about the status of a plurality of storage battery strings STR1 to STRm, and transmits bypass control information for controlling bypass switch units B1 to Bn to string controllers C1 to Cm based on the information. The plurality of string controllers C1 to Cm control power converters PC1 to PCm of the corresponding storage battery strings STR1 to STRm according to charging / discharging power values or charging / discharging current values of the storage battery strings STR1 to STRm set by the system controller 101, and control the bypass switch units B1 to Bn of the corresponding storage battery strings STR1 to STRm according to the bypass control information transmitted from the system controller 101.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a storage battery control device and a storage battery connection control device. [Background technology]

[0002] There is known an energy storage system including a plurality of storage battery strings connected in parallel and a plurality of power converters provided for each storage battery string (see, for example, Patent Document 1). In the energy storage system described in Patent Document 1, the storage battery string includes a plurality of storage battery modules connected in series, and the power converter is controlled by a controller to convert the output of the storage battery string to a set voltage of a load supply bus.

[0003] Also, as a power storage system having multiple strings connected in parallel, one is known that includes multiple bypass switch units provided for each of multiple storage battery modules connected in series, and multiple string cutoff switches provided for each storage battery string (for example, see Patent Document 2). The bypass switch units are controlled by a controller to switch the storage battery modules between a connected state and a bypass state. Also, the string cutoff switches are controlled by the controller to switch the storage battery strings between a connected state and a cutoff state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-156200 A [Patent Document 2] JP 2022-29299 A Summary of the Invention [Problem to be solved by the invention]

[0005] Consider a large-scale battery system equipped with multiple power converters, multiple bypass switch units, and multiple string cutoff switches. In this case, if a single controller is used to control a large number of power converters and an even larger number of bypass switch units, the processing load on the controller will be excessive. On the other hand, if the control of the large number of power converters and the control of the even larger number of bypass switch units are shared among multiple controllers provided for each battery string, cooperative control between the battery strings will be difficult.

[0006] In view of the above circumstances, an object of the present invention is to provide a battery control device and a battery connection control device that can ensure processing capacity even in a large-scale energy storage system and realize cooperative control between battery strings. [Means for solving the problem]

[0007] The battery control device of the present invention includes a plurality of battery strings connected in parallel to each other, and the battery string includes a plurality of batteries connected in series, a first switch connected in series to the storage battery, and a second switch connected in parallel to the storage battery and the first switch, Bypass state or connection state R A plurality of storage batteries are provided for each storage battery. bypass Switch Unit and a power converter that converts input / output power of the storage battery string, the storage battery control device comprising: a plurality of first control devices provided for each of the storage battery strings; and a second control device that is communicatively connected to the plurality of first control devices and sets a charge / discharge power value or a charge / discharge current value of the storage battery string, the first control device or the second control device controlling the power converter of the corresponding storage battery string in accordance with the charge / discharge power value or the charge / discharge current value of the storage battery string set by the second control device, and the second control device acquiring information on states of the plurality of storage battery strings and and the charging and discharging power required for the power storage system. Based on the above, the bypass Switch Unit Bypass control information for controlling GenerateThe first control device controls the bypass of the corresponding battery string in response to the bypass control information transmitted from the second control device. Switch Unit Control.

[0008] The storage battery connection control device of the present invention is a storage battery connection control device used in a power storage system including a plurality of storage battery strings connected in parallel with each other, the storage battery strings including a plurality of storage batteries connected in series, the storage battery connection control device including a plurality of storage battery connection modules provided for each of the storage battery strings, a plurality of first control devices provided for each of the storage battery strings, and a second control device communicatively connected to the plurality of first control devices and setting a charge / discharge power value or a charge / discharge current value of the storage battery strings, the storage battery connection module including a power line connecting the plurality of storage batteries in series, a first switch connected in series to the storage battery, and a second switch connected in parallel to the storage battery and the first switch, Bypass state or connection state R A plurality of storage batteries are provided for each storage battery. bypass Switch Unit and a power converter that converts input / output power of the storage battery string, wherein the first control device or the second control device controls the power converter of the corresponding storage battery string in accordance with a charge / discharge power value or a charge / discharge current value of the storage battery string set by the second control device, and the second control device acquires information on states of the plurality of storage battery strings and and the charging and discharging power required for the power storage system. Based on the above, the bypass Switch Unit Bypass control information for controlling Generate The first control device controls the bypass of the corresponding battery string in response to the bypass control information transmitted from the second control device. Switch Unit Control. Effect of the Invention

[0009] According to the present invention, processing capacity can be ensured even in a large-scale energy storage system, and cooperative control between battery strings can be realized. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 is a circuit diagram showing an outline of a power storage system including a battery control device and a battery connection control device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a circuit diagram showing an outline of a power storage system including a storage battery control device and a storage battery connection control device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below along with preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and the embodiments can be appropriately modified within the scope of the present invention. In addition, in the embodiments shown below, some configurations are omitted from illustration and description, but for the details of the omitted technologies, publicly known or well-known technologies are appropriately applied within the scope of not causing any contradiction with the contents described below.

[0012] Fig. 1 is a circuit diagram showing an outline of a power storage system 1 including a battery control device 100 and a battery connection control device 1000 according to one embodiment of the present invention. As shown in this diagram, the power storage system 1 includes m sets of storage battery strings STR1 to STRm (m is an integer of 2 or more), a string bus 3, and the battery control device 100. The m sets of storage battery strings STR1 to STRm are connected in parallel to each other and to an external system (not shown) via the string bus 3. The power storage system 1 is a stationary or vehicle-mounted power source.

[0013] The storage battery strings STR1 to STRm include n (n is an integer of 2 or more) storage battery modules M1 to Mn connected in series. Although not particularly limited, the storage battery strings STR1 to STRm in this embodiment are regenerated second-hand storage batteries, and the storage battery modules M1 to Mn have different degrees of deterioration. The storage battery modules M1 to Mn are, for example, a plurality of cells of secondary batteries such as lithium ion batteries or lithium ion capacitors connected together.

[0014] The storage battery modules M1 to Mn are charged by receiving power from an external system via the string bus 3 and power converters PC1 to PCm described later. In addition, the storage battery modules M1 to Mn supply power to the external system via the power converters PC1 to PCm and the string bus 3.

[0015] The external system includes a load, a generator, etc. When the power storage system 1 is for stationary use, household appliances, commercial power systems, liquid crystal displays, communication modules, etc. are the loads, and a solar power generation system, etc. are the generators. On the other hand, when the power storage system 1 is for vehicle use, the drive motor, air conditioner, various vehicle electrical equipment, etc. are the loads. The drive motor is both a load and a generator.

[0016] The battery strings STR1 to STRm may include n battery cells or battery packs connected in series, instead of the n battery modules M1 to Mn connected in series. The power storage system 1 may include a bypass circuit that bypasses each battery cell or each battery pack.

[0017] Each of the storage battery strings STR1 to STRm includes one power converter PC1 to PCm, one string cutoff switch 11, and n bypass switch units B1 to Bn. Each of the storage battery strings STR1 to STRm also includes n voltage sensors 12, one current sensor 13, one voltage sensor 14, one fuse 15, n temperature sensors (not shown), and a number of cell voltage sensors (not shown).

[0018] The power converters PC1 to PCm are DC / DC converters or DC / AC converters, and are connected to the string bus 3. In addition, the power converters PC1 to PCm are connected to the positive electrode of the starting storage battery module M1 and the negative electrode of the terminal storage battery module Mn.

[0019] When the storage battery strings STR1-STRm are being charged, the power converters PC1-PCm convert the voltage input from the string bus 3 according to a charging power value or a charging current value, which will be described later, and output the converted voltage to the multiple storage battery modules M1-Mn. Here, the voltage on the side of the storage battery strings STR1-STRm changes according to the bypass state of the storage battery modules M1-Mn (the number of bypassed storage battery modules M1-Mn) and the charging state of the storage battery modules M1-Mn. Therefore, when the storage battery strings STR1-STRm are being charged, the power converters PC1-PCm convert the voltage input from the string bus 3 into the voltage on the side of the storage battery strings STR1-STRm and output the converted voltage to the multiple storage battery modules M1-Mn.

[0020] When the storage battery strings STR1-STRm are discharged, the power converters PC1-PCm convert the voltage input from the multiple storage battery modules M1-Mn according to a discharge power value or a discharge current value, which will be described later, and output the converted voltage to the string bus 3. Here, the input voltage of the power converters PC1-PCm during discharge varies according to the bypass state of the storage battery modules M1-Mn and the charge state of the storage battery modules M1-Mn. This causes variations in the input voltage of the power converters PC1-PCm among the storage battery strings STR1-STRm during discharge. Therefore, when the storage battery strings STR1-STRm are discharged, the power converters PC1-PCm convert the input voltage to a voltage that matches the other storage battery strings STR1-STRm, and output the converted voltage to the string bus 3.

[0021] When the current flowing through the string bus 3 is a direct current, the power converters PC1 to PCm are DC / DC converters, and when the current flowing through the string bus 3 is an alternating current, the power converters PC1 to PCm are DC / AC converters. When the current flowing through the string bus 3 is an alternating current, the power converters PC1 to PCm are provided with synchronization means for following changes in instantaneous values.

[0022] The string cutoff switch 11 is provided between each of the power converters PC1 to PCm and the string bus 3. The string cutoff switch 11 connects or disconnects the storage battery strings STR1 to STRm to the string bus 3. In addition, the fuse 15 is a power fuse provided between the string cutoff switch 11 and the string bus 3.

[0023] The voltage sensor 12 is connected between the positive and negative terminals of each of the storage battery modules M1 to Mn, detects the terminal voltage of each of the storage battery modules M1 to Mn, and transmits the detection signal to the string controllers C1 to Cm described later. The current sensor 13 is provided on the power line PL of each of the storage battery strings STR1 to STRm, detects the charge / discharge current of the storage battery strings STR1 to STRm, and transmits the detection signal to the string controllers C1 to Cm. The voltage sensor 14 is provided on the power line PL of each of the storage battery strings STR1 to STRm, detects the voltage of the storage battery strings STR1 to STRm, and transmits the detection signal to the string controllers C1 to Cm. The temperature sensor is provided in each of the storage battery modules M1 to Mn, detects the temperature of each of the storage battery modules M1 to Mn, and transmits the detection signal to the string controllers C1 to Cm. The cell voltage sensor is provided for each storage battery cell of each of the storage battery modules M1 to Mn, and detects the voltage of the storage battery cell, and transmits the detection signal to the string controllers C1 to Cm.

[0024] The bypass switch units B1 to Bn are provided for each of the storage battery modules M1 to Mn. Each of the bypass switch units B1 to Bn includes a bypass line BL and switches S1 and S2. The bypass line BL is a power line that bypasses each of the storage battery modules M1 to Mn. The switch S1 is provided on the bypass line BL. The switch S1 is, for example, a mechanical relay or a semiconductor switch. The switch S2 is provided between the positive electrode of each of the storage battery modules M1 to Mn and one end of the bypass line BL. The switch S2 is, for example, a mechanical relay or a semiconductor switch.

[0025] The starting battery module M1 and the ending battery module Mn are connected to an external system via power converters PC1-PCm and a string bus 3. When the switches S1 are turned OFF and the switches S2 are turned ON in all the bypass switch units B1-Bn, all the battery modules M1-Mn are connected in series to the external system. On the other hand, when the switches S2 are turned OFF and the switches S1 are turned ON in any of the bypass switch units B1-Bn, the battery module M1-Mn corresponding to that bypass switch unit B1-Bn is bypassed.

[0026] The battery connection control device 1000 includes m sets of battery connection modules CM1 to CMm and a battery control device 100. The battery connection modules CM1 to CMm are provided for each of the battery strings STR1 to STRm, and connect the multiple battery modules M1 to Mn of the corresponding battery strings STR1 to STRm in series.

[0027] Each of the battery connection modules CM1-CMm includes a power line PL that connects the plurality of battery modules M1-Mn in series, one power converter PC1-PCm, one string cutoff switch 11, and n bypass switch units B1-Bn. Each of the battery connection modules CM1-CMm also includes n voltage sensors 12, one current sensor 13, one voltage sensor 14, one fuse 15, n temperature sensors, and a number of cell voltage sensors.

[0028] The battery control device 100 includes m string controllers C1 to Cm and one system controller 101. The string controllers C1 to Cm are provided for each of the battery strings STR1 to STRm.

[0029] The string controllers C1-Cm control the switches S1, S2 of the bypass switch units B1-Bn of the corresponding battery strings STR1-STRm and the string cutoff switch 11. The string controllers C1-Cm also control the power converters PC1-PCm of the corresponding battery strings STR1-STRm. The power converters PC1-PCm convert the charge / discharge voltages of the battery strings STR1-STRm in accordance with control signals transmitted from the corresponding string controllers C1-Cm.

[0030] The string controllers C1-Cm execute detection of the states of the corresponding storage battery strings STR1-STRm, estimation of the states of the corresponding storage battery strings STR1-STRm, notification of device control requests to the system controller 101, etc. Examples of detection of the states of the storage battery strings STR1-STRm include detection of the charge / discharge currents of the storage battery strings STR1-STRm based on a detection signal from the current sensor 13, detection of the voltages of the storage battery strings STR1-STRm based on a detection signal from the voltage sensor 14, detection of the voltages of the storage battery modules M1-Mn based on a detection signal from the voltage sensor 12, detection of the temperatures of the storage battery modules M1-Mn based on a detection signal from a temperature sensor, detection of the voltages of the storage battery cells based on a detection signal from a cell voltage sensor, etc. Examples of estimation of the states of the storage battery strings STR1-STRm include estimation of the SOC (State of Charge) and SOH (State of Health) of the storage battery modules M1-Mn, and estimation of the SOC of the storage battery strings STR1-STRm. Furthermore, notifications of device control requests to the system controller 101 include requests for switching control of the switches S1, S2 of the bypass switch units B1 to Bn and the string cutoff switch 11, and requests for control of the power converters PC1 to PCm.

[0031] Methods for estimating SOH include methods using charge / discharge tests, current integration methods, open circuit voltage measurements, terminal voltage measurements, model-based methods (all of which use the change in SOC over time), AC impedance measurements, model-based methods using an adaptive digital filter, linear regression from IV characteristics (current-voltage characteristics) (the slope of the straight line of the IV characteristics), and step response methods (all of which are methods of estimation using the increase in internal resistance over time).

[0032] Methods for estimating the SOC include various known methods such as a current integration method, a method (voltage method) that is calculated from the OCV (Open Circuit Voltage), a method that combines the current integration method and the voltage method, etc. Also, the OCV can be estimated using various known methods that estimate the OCV using the change in terminal voltage over time or the increase in internal resistance over time.

[0033] The system controller 101 is a controller that performs overall control of the entire power storage system 1, and executes 1:m communication with m string controllers C1-Cm. This system controller 101 monitors the states of the storage battery strings STR1-STRm, judges whether to accept device control requests from the string controllers C1-Cm, and notifies the string controllers C1-Cm of permission for the device control requests. In addition, the system controller 101 sets charge / discharge power values ​​(charge power value and discharge power value) or charge / discharge current values ​​(charge current value and discharge current value) of the storage battery strings STR1-STRm, and transmits the charge / discharge power values ​​or charge / discharge current values ​​to the string controllers C1-Cm.

[0034] The system controller 101 monitors the states of the storage battery strings STR1-STRm based on the detection results or estimation results of the states of the storage battery strings STR1-STRm transmitted from the string controllers C1-Cm. Then, the system controller 101 calculates the charge / discharge power values ​​or charge / discharge current values ​​of the storage battery strings STR1-STRm in response to an instruction of the charge / discharge power or charge / discharge current of the entire power storage system 1 from a higher-level controller (not shown). At this time, the system controller 101 calculates the charge / discharge power values ​​or charge / discharge current values ​​of the storage battery strings STR1-STRm in response to the states of the storage battery strings STR1-STRm being monitored. For example, the string controllers C1-Cm calculate the limit value of the charge / discharge current based on the SOC and OCV of the storage battery modules M1-Mn and transmit it to the system controller 101. Then, the system controller 101 calculates the charge / discharge current of the storage battery strings STR1-STRm corresponding to the string controllers C1-Cm so that the charge / discharge current is below the charge / discharge current limit value transmitted from the string controllers C1-Cm.

[0035] The system controller 101 judges whether to accept a device control request from the string controllers C1-Cm depending on the state of the other storage battery strings STR1-STRm that it is monitoring. For example, it is possible that a bypass control request is transmitted from a certain string controller C1-Cm in a situation where the charge / discharge power of the other storage battery strings STR1-STRm is kept low by current limiting. In such a situation, the system controller 101 may reject the control request in order to ensure the charge / discharge power required for the power storage system 1.

[0036] When the system controller 101 permits a device control request from the string controllers C1-Cm, it transmits a notification of permission for the control request to the string controllers C1-Cm. The string controllers C1-Cm that have received the notification of permission for the control request for the bypass switch units B1-Bn or the string cutoff switch 11 execute switching control of the bypass switch units B1-Bn or the string cutoff switch 11. In addition, the string controllers C1-Cm that have received the notification of permission for the control request for the power converters PC1-PCm execute control of the corresponding power converters PC1-PCm.

[0037] In a situation where a device control request is not transmitted from a certain string controller C1-Cm, the system controller 101 may transmit a device control instruction to the string controller C1-Cm as necessary. For example, a situation may be considered in which the charge / discharge power of the other storage battery strings STR1-STRm is suppressed to a low level by current limitation, while the storage battery strings STR1-STRm corresponding to the string controller C1-Cm that has not transmitted a device control request are cut off by the string cutoff switch 11. In such a situation, in order to ensure a charge / discharge current required for the power storage system 1, the system controller 101 may transmit a control instruction to switch the string cutoff switch 11 from OFF to ON to the string controller C1-Cm that has not transmitted a device control request.

[0038] When the string controllers C1 to Cm detect an abnormality in the storage battery strings STR1 to STRm, they turn off the string cutoff switches 11 regardless of whether or not the system controller 101 has notified them of permission to control or given them a control instruction.

[0039] As described above, the battery control device 100 of this embodiment includes a plurality of (m) string controllers C1 to Cm provided for each of the battery strings STR1 to STRm, and a system controller 101 communicatively connected to the plurality of string controllers C1 to Cm.

[0040] The system controller 101 is responsible for the following processes (1) to (3). (1) Processing for setting the charge / discharge power values ​​or charge / discharge current values ​​of the storage battery strings STR1 to STRm (2) A process of acquiring detection information and estimation information regarding the states of m sets of storage battery strings STR1 to STRm from m string controllers C1 to Cm. (3) A process of determining whether or not to permit a control request for the bypass switch units B1 to Bn based on the obtained detection information and estimation information on the states of the m sets of storage battery strings STR1 to STRm, and transmitting a notification of permission for the control request to the string controllers C1 to Cm.

[0041] On the other hand, the string controllers C1 to Cm are responsible for the following processes (4) to (6). (4) Processing for detecting and estimating the states of the storage battery strings STR1 to STRm and transmitting the detected information and the estimated information to the system controller 101 (5) Processing for controlling the power converters PC1 to PCm of the corresponding storage battery strings STR1 to STRm in accordance with the charge / discharge power values ​​or charge / discharge current values ​​of the storage battery strings STR1 to STRm set by the system controller 101 (6) Processing for controlling the bypass switch units B1 to Bn of the corresponding storage battery strings STR1 to STRm in response to a notification of permission of a control request for the bypass switch units B1 to Bn transmitted from the system controller 101

[0042] That is, the battery control device 100 of this embodiment divides processing between the system controller 101 and the string controllers C1-Cm. This makes it possible to prevent excessive concentration of the processing load on the system controller 101. Therefore, it is possible to ensure the processing capacity of the battery control device 100 even in a large-scale power storage system 1 having a large number of storage battery strings STR1-STRm and bypass switch units B1-Bn.

[0043] Furthermore, the system controller 101 acquires information on the states of the m storage battery strings STR1-STRm from the m string controllers C1-Cm, and determines whether or not to accept a control request for the bypass switch units B1-Bn based on the information. This makes it possible to realize coordinated control of the bypass switch units B1-Bn of the multiple storage battery strings STR1-STRm.

[0044] Furthermore, in the battery control device 100 of the present embodiment, the string controllers C1 to Cm are responsible for the following process (7), and the system controller 101 is responsible for the above processes (2) and (3). This makes it possible to further reduce the processing load on the system controller 101. (7) A process of acquiring information about the states of the battery strings STR1 to STRm (such as the currents of the battery strings STR1 to STRm) from sensors (such as the current sensor 13) provided in the battery strings STR1 to STRm.

[0045] Furthermore, in the battery control device 100 of the present embodiment, the string controllers C1 to Cm are responsible for the following process (8), and the system controller 101 is responsible for the above processes (2) and (3). This makes it possible to further reduce the processing load on the system controller 101. (8) A process of estimating information on the states of the storage battery strings STR1 to STRm (such as the SOC and OCV of the storage battery modules M1 to Mn) based on information detected by sensors (such as the voltage sensor 12 and the current sensor 13) included in the storage battery strings STR1 to STRm and transmitting the information to the system controller 101.

[0046] Moreover, in the battery control device 100 of the present embodiment, the string controllers C1 to Cm are responsible for the following process (9). This makes it possible to further reduce the processing load on the system controller 101. (9) Processing for controlling the string cutoff switches 11 of the storage battery strings STR1 to STRm

[0047] Next, another embodiment of the battery control device 100 will be described. The circuit configuration of the power storage system 1 is the same as that described above, as shown in Fig. 1. The battery control device 100 of this embodiment includes m string controllers C1 to Cm provided for each of the battery strings STR1 to STRm, and one system controller 101, as in the above embodiment.

[0048] The string controllers C1-Cm control the switches S1, S2 and string cutoff switches 11 of the bypass switch units B1-Bn of the corresponding storage battery strings STR1-STRm, and the power converters PC1-PCm. The power converters PC1-PCm convert the charge / discharge voltages of the storage battery strings STR1-STRm in accordance with control signals transmitted from the corresponding string controllers C1-Cm.

[0049] Further, the string controllers C1 to Cm execute detection and estimation of the states of the corresponding storage battery strings STR1 to STRm. Here, the string controllers C1 to Cm differ from the above-described embodiment in that they do not execute notification of a device control request to the system controller 101.

[0050] As in the above-described embodiment, the system controller 101 is a controller that comprehensively controls the entire power storage system 1, and executes 1:m communication with m string controllers C1-Cm. This system controller 101 monitors the states of the storage battery strings STR1-STRm, sets charge / discharge power values ​​or charge / discharge current values ​​of the storage battery strings STR1-STRm, and transmits the charge / discharge power values ​​or charge / discharge current values ​​to the string controllers C1-Cm.

[0051] Here, the system controller 101 does not judge whether or not to accept a device control request from the string controllers C1-Cm, nor notifies the string controllers C1-Cm of permission for the device control request. Instead, the system controller 101 transmits control instructions to the string controllers C1-Cm for controlling the devices of the storage battery strings STR1-STRm. The devices of the storage battery strings STR1-STRm include bypass switch units B1-Bn, a string cutoff switch 11, and power converters PC1-PCm.

[0052] The system controller 101 monitors the states of the m storage battery strings STR1-STRm based on the detection results and estimation results of the states of the m storage battery strings STR1-STRm transmitted from the string controllers C1-Cm, as in the above-described embodiment. Then, the system controller 101 calculates the charge / discharge power values ​​or charge / discharge current values ​​of the storage battery strings STR1-STRm in response to an instruction for charge / discharge power or charge / discharge current of the entire power storage system 1 from a higher-level controller (not shown), as in the above-described embodiment.

[0053] The system controller 101 generates control instructions for the devices of the storage battery strings STR1-STRm according to the states of the other storage battery strings STR1-STRm and transmits the control instructions to the corresponding string controllers C1-Cm. For example, it is conceivable to transmit a control instruction for the devices of a certain storage battery string STR1-STRm in a situation where the charge / discharge power of the other storage battery strings STR1-STRm is kept low by current limiting. In such a situation, the system controller 101 may transmit a control instruction to minimize the number of bypasses of the storage battery modules M1-Mn in order to ensure the charge / discharge power required for the power storage system 1.

[0054] The string controllers C1-Cm that receive control instructions for the bypass switch units B1-Bn and the string cutoff switch 11 execute switching control of the switches S1, S2 of the bypass switch units B1-Bn and the string cutoff switch 11. In addition, the string controllers C1-Cm that receive notifications of control instructions for the power converters PC1-PCm execute control of the power converters PC1-PCm.

[0055] When the string controllers C1 to Cm detect an abnormality in the storage battery strings STR1 to STRm, they turn off the string cutoff switches 11 regardless of whether or not a control instruction is received from the system controller 101.

[0056] As described above, the battery control device 100 of this embodiment includes a plurality of (m) string controllers C1 to Cm provided for each of the battery strings STR1 to STRm, and a system controller 101 communicatively connected to the plurality of string controllers C1 to Cm.

[0057] The system controller 101 is responsible for the following processes (10) to (12). (10) Processing for setting charge / discharge power values ​​or charge / discharge current values ​​of storage battery strings STR1 to STRm (11) A process of acquiring detection information and estimation information regarding the states of m sets of storage battery strings STR1 to STRm from the string controllers C1 to Cm. (12) A function of generating control instructions for the bypass switch units B1 to Bn based on the acquired detection information and estimation information regarding the states of the m sets of storage battery strings STR1 to STRm and transmitting the control instructions to the string controllers C1 to Cm.

[0058] On the other hand, the string controllers C1 to Cm have the following functions (13) to (15). (13) A function of detecting and estimating the states of the storage battery strings STR1 to STRm and transmitting the detected information and the estimated information to the system controller 101. (14) A function of controlling the power converters PC1 to PCm of the corresponding storage battery strings STR1 to STRm in accordance with the charge / discharge power values ​​or charge / discharge current values ​​of the corresponding storage battery strings STR1 to STRm set by the system controller 101. (15) A function of controlling the bypass switch units B1 to Bn of the corresponding storage battery strings STR1 to STRm in response to control instructions for the bypass switch units B1 to Bn transmitted from the system controller 101.

[0059] That is, the battery control device 100 of this embodiment divides processing between the system controller 101 and the string controllers C1-Cm. This makes it possible to prevent excessive concentration of the processing load on the system controller 101. Therefore, it is possible to ensure the processing capacity of the battery control device 100 even in a large-scale power storage system 1 having a large number of storage battery strings STR1-STRm and bypass switch units B1-Bn.

[0060] Furthermore, the system controller 101 acquires information on the states of the storage battery strings STR1-STRm from the string controllers C1-Cm, and based on the information, generates control instructions for the bypass switch units B1-Bn and transmits them to the string controllers C1-Cm. This makes it possible to realize coordinated control of the bypass switch units B1-Bn of the multiple storage battery strings STR1-STRm.

[0061] 2 is a circuit diagram showing an outline of a power storage system 2 including a battery control device 200 and a battery connection control device 2000 according to another embodiment of the present invention. As shown in this diagram, the battery connection control device 2000 includes m sets of battery connection modules CM1-CMm and a battery control device 200. The battery connection modules CM1-CMm are provided for each of the battery strings STR1-STRm, and connect the multiple battery modules M1-Mn of the corresponding battery strings STR1-STRm in series.

[0062] In the power storage system 2 and the battery connection control device 2000 of this embodiment, the devices of the battery strings STR1-STRm controlled by the string controllers C1-Cm are only the bypass switch units B1-Bn. On the other hand, in the power storage system 2 and the battery connection control device 2000 of this embodiment, the system controller 101 controls the string cutoff switch 11 and the power converters PC1-PCm.

[0063] The string controllers C1 to Cm control the switches S1, S2 of the corresponding bypass switch units B1 to Bn.

[0064] The system controller 101 transmits control signals to the string cutoff switches 11 and the power converters PC1-PCm of the storage battery strings STR1-STRm. The string cutoff switches 11 are turned ON / OFF in accordance with the control signals transmitted from the system controller 101. In addition, the power converters PC1-PCm convert the charge / discharge voltages of the storage battery strings STR1-STRm in accordance with the control signals transmitted from the system controller 101.

[0065] Here, the string controllers C1 to Cm do not detect the states of the storage battery strings STR1 to STRm, nor estimate the states of the storage battery strings STR1 to STRm. In addition, the string controllers C1 to Cm do not notify the system controller 101 of a control request.

[0066] As in the above-described embodiment, the system controller 101 is a controller that performs overall control of the entire power storage system 2, and executes 1:m communication with m string controllers C1 to Cm. This system controller 101 monitors the states of the storage battery strings STR1 to STRm, and sets the charge / discharge power values ​​or charge / discharge current values ​​of the storage battery strings STR1 to STRm. In addition, the system controller 101 detects the states of the storage battery strings STR1 to STRm, and estimates the states of the storage battery strings STR1 to STRm.

[0067] The system controller 101 detects the charge / discharge currents of the storage battery strings STR1-STRm based on a detection signal from the current sensor 13. The system controller 101 also detects the voltages of the storage battery strings STR1-STRm based on a detection signal from the voltage sensor 14. The system controller 101 also detects the voltages of the storage battery modules M1-Mn based on a detection signal from the voltage sensor 12. The system controller 101 also detects the temperatures of the storage battery modules M1-Mn based on a detection signal from a temperature sensor (not shown). The system controller 101 also detects the voltages of the storage battery cells based on a detection signal from a cell voltage sensor (not shown).

[0068] The system controller 101 also estimates the SOC and SOH of the storage battery modules M1 to Mn, estimates the SOC of the storage battery strings STR1 to STRm, etc. Furthermore, the system controller 101 generates control instructions for controlling the switches S1 and S2 of the bypass switch units B1 to Bn and transmits them to the string controllers C1 to Cm.

[0069] As described above, the battery control device 200 of this embodiment includes a plurality of (m) string controllers C1 to Cm provided for each of the battery strings STR1 to STRm, and a system controller 101 communicatively connected to the plurality of string controllers C1 to Cm.

[0070] The system controller 101 is responsible for the following processes (16) to (20). (16) Processing for setting charge / discharge power values ​​or charge / discharge current values ​​of storage battery strings STR1 to STRm (17) Processing for detecting and estimating the state of m sets of storage battery strings STR1 to STRm (18) A process of generating control instructions for the bypass switch units B1 to Bn based on the detection results and estimation results regarding the states of the m sets of storage battery strings STR1 to STRm and transmitting the control instructions to the string controllers C1 to Cm. (19) Processing for controlling the power converters PC1 to PCm of the corresponding storage battery strings STR1 to STRm in accordance with the charge / discharge power value or charge / discharge current value of the storage battery strings STR1 to STRm set by the storage battery strings STR1 to STRm itself (20) Processing for controlling the string cutoff switches 11 of the storage battery strings STR1 to STRm

[0071] On the other hand, the string controllers C1 to Cm are responsible for the following process (21). (21) Processing for controlling the bypass switch units B1 to Bn of the corresponding storage battery strings STR1 to STRm in response to control instructions for the bypass switch units B1 to Bn transmitted from the system controller 101

[0072] That is, the battery control device 200 of this embodiment divides processing between the system controller 101 and the string controllers C1-Cm. This makes it possible to prevent excessive concentration of the processing load on the system controller 101. Therefore, it is possible to ensure the processing capacity of the battery control device 200 even in a large-scale power storage system 1 having a large number of storage battery strings STR1-STRm and bypass switch units B1-Bn.

[0073] Furthermore, the system controller 101 detects and estimates the states of the m sets of storage battery strings STR1-STRm, and transmits control instructions for the bypass switch units B1-Bn to the string controllers C1-Cm based on the results of the detection. This makes it possible to realize coordinated control of the bypass switch units B1-Bn of the multiple storage battery strings STR1-STRm.

[0074] The present invention has been described above based on the above-mentioned embodiment, but the present invention is not limited to the above-mentioned embodiment, and modifications may be made without departing from the spirit of the present invention, and publicly known or well-known technologies may be combined as appropriate.

[0075] The division of processing between the system controller 101 and the string controllers C1-Cm may be changed as appropriate, for example, by having the system controller 101 take charge of both. For example, the processing for detecting the states of the strings STR1-STRm may be performed by the string controllers C1-Cm, and the processing for estimating the states of the strings STR1-STRm may be performed by the system controller 101. Furthermore, the control of the string cutoff switch 11 may be performed by the string controllers C1-Cm, and the control of the power converters PC1-PCm may be performed by the system controller 101. [Explanation of symbols]

[0076] 1: Energy storage system 2: Energy storage system 11: String cutoff switch 12: Voltage sensor (status detector) 13: Current sensor (status detector) 14: Voltage sensor (status detector) 100: Battery control device 101: System controller (second control device) 200: Battery control device 1000: Battery connection control device 2000: Battery connection control device B1~Bn: Bypass switch unit (bypass circuit) C1~Cm: String controller (first control device) CM1~CMm: Battery connection module M1~Mn: Battery module (battery) PC1~PCm: Power converter PL: Power line STR1~STRm: Battery strings

Claims

1. A battery control device for controlling a power storage system including a plurality of storage battery strings connected in parallel to each other, the storage battery strings including a plurality of storage batteries connected in series, a first switch connected in series to the storage batteries, and a second switch connected in parallel to the storage batteries and the first switch, the plurality of bypass switch units provided for each of the storage batteries to put the storage batteries into a bypass state or a connected state, and a power converter for converting input / output power of the storage battery strings, A plurality of first control devices provided for each of the storage battery strings; a second control device that is communicatively connected to a plurality of the first control devices and that sets a charge / discharge power value or a charge / discharge current value of the storage battery string; Equipped with the first control device or the second control device controls the power converter of the corresponding storage battery string in accordance with a charge / discharge power value or a charge / discharge current value of the storage battery string set by the second control device; the second control device acquires information on states of the plurality of storage battery strings, and generates bypass control information for controlling the bypass switch unit based on the acquired information and charge / discharge power required for the power storage system, and transmits the bypass control information to the first control device; The first control device is a battery control device that controls the bypass switch unit of the corresponding battery string in response to the bypass control information transmitted from the second control device.

2. the first control device determines whether or not it is necessary to control the bypass switch unit of the corresponding battery string based on information about a state of the battery string, and transmits a control request for the bypass switch unit to the second control device; 2. The battery control device according to claim 1, wherein the second control device determines whether or not the control request transmitted from the first control device is acceptable based on information about the states of the multiple battery strings that have been acquired and the charging / discharging power required for the energy storage system, and transmits permission information for permitting the control request as the bypass control information to the first control device that transmitted the control request.

3. 2. The battery control device according to claim 1, wherein the second control device determines whether or not the bypass switch unit needs to be controlled based on the acquired information about the states of the plurality of storage battery strings and the charge / discharge power required for the power storage system, and transmits instruction information instructing the control of the bypass switch unit as the bypass control information to the first control device that controls the bypass switch unit.

4. The information about the state of the battery string includes at least one of a current of the battery string, a voltage of the battery string, a voltage of the battery, and a temperature of the battery, and is detected by a state detector included in the battery string; The first control device acquires information about a state of the corresponding battery string from the state detector included in the corresponding battery string, and transmits the information to the second control device; The battery control device according to claim 1 or 2, wherein the second control device generates the bypass control information based on information about the state of the battery string obtained from a plurality of the first control devices and the charge / discharge power required for the energy storage system, and transmits the bypass control information to the first control device.

5. The information about the state of the battery string includes at least one of a SOC of the battery, an OCV of the battery, a SOH of the battery, and a SOC of the battery string; the first control device estimates information about a state of the corresponding storage battery string based on detection information of a state detector included in the storage battery string, and transmits the information to the second control device; The battery control device according to claim 1 or 2, wherein the second control device generates the bypass control information based on information about the state of the battery string obtained from a plurality of the first control devices and the charge / discharge power required for the energy storage system, and transmits the bypass control information to the first control device.

6. The battery control device according to claim 1 or 2, wherein the first control device controls the power converter of the corresponding battery string in accordance with a charge / discharge power value or a charge / discharge current value of the corresponding battery string set by the second control device.

7. the power storage system includes a string shutoff switch provided for each of the storage battery strings and configured to shut off the storage battery string; The battery control device according to claim 1 or 2, wherein the first control device controls the string cutoff switch of the corresponding battery string.

8. A battery connection control device for use in a power storage system including a plurality of battery strings connected in parallel to each other, the battery string including a plurality of battery strings connected in series, the battery connection control device comprising: A plurality of battery connection modules provided for each of the battery strings; A plurality of first control devices provided for each of the storage battery strings; a second control device that is communicatively connected to a plurality of the first control devices and that sets a charge / discharge power value or a charge / discharge current value of the storage battery string; Equipped with The battery connection module includes: A power line connecting a plurality of the storage batteries in series; a plurality of bypass switch units each provided for each of the storage batteries, the bypass switch units including a first switch connected in series to the storage battery and a second switch connected in parallel to the storage battery and the first switch, the bypass switch units setting the storage battery in a bypass state or a connected state; a power converter that converts input and output power of the storage battery string; Equipped with the first control device or the second control device controls the power converter of the corresponding storage battery string in accordance with a charge / discharge power value or a charge / discharge current value of the storage battery string set by the second control device; the second control device acquires information on states of the plurality of storage battery strings, and generates bypass control information for controlling the bypass switch unit based on the acquired information and charge / discharge power required for the power storage system, and transmits the bypass control information to the first control device; The first control device is a battery connection control device that controls the bypass switch unit of the corresponding battery string in response to the bypass control information transmitted from the second control device.

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