JP-7856200-B2 - Stationary energy storage system

Inventors

• 青木 嘉範
• 土田 祥生

Assignees

• トヨタ自動車株式会社

Dates

Publication Date

20260511

Application Date

20250709

Claims (5)

1. Multiple energy storage devices connected in parallel to each other, Each of the aforementioned multiple energy storage devices is provided with a relay and a current sensor, A stationary energy storage system comprising a control device that controls the current value of each of the plurality of energy storage devices, The control device is configured to select a predetermined number of energy storage devices from among the plurality of energy storage devices as learning targets, and to select one or more of the energy storage devices other than the learning targets as control targets to be used for energy management. The control device is The current is interrupted by the relay corresponding to the learning target, and the output value of the current sensor corresponding to the learning target is obtained. A stationary energy storage system configured to correct the detection error of the current sensor corresponding to the learning target based on the acquired output value.
2. The stationary energy storage system according to claim 1, wherein the control device is configured to preferentially select the energy storage device with the shortest elapsed time since the most recent correction of the detection error of the corresponding current sensor as the target for control.
3. The stationary energy storage system is Each of the plurality of energy storage devices is provided with a power conversion circuit that transforms the output voltage of the energy storage device in accordance with a command from the control device, The stationary energy storage system according to claim 1, wherein the plurality of energy storage devices include a first energy storage device including a first battery and a second energy storage device including a second battery of a different type from the first battery.
4. The control device is configured to repeatedly perform the selection of the learning target and the control target, The stationary energy storage system according to any one of claims 1 to 3, wherein the control device is configured to change the learning target each time it is selected so that the detection error correction is performed sequentially for the current sensors of the plurality of energy storage devices.
5. The stationary energy storage system is configured to perform energy management of the power grid in response to requests from a server that manages the power grid. The stationary energy storage system according to any one of claims 1 to 3, wherein the control device is configured to constantly receive the request from the server.

Description

This disclosure relates to a stationary energy storage system. Japanese Patent Publication No. 2012-113856 (Patent Document 1) discloses a vehicle equipped with a battery pack in which multiple battery stacks are connected in parallel. Japanese Patent Publication No. 2012-113856 This figure shows a schematic configuration of the energy management system according to the embodiment of the disclosure.This is a flowchart showing an energy management method according to an embodiment of the present disclosure.This diagram illustrates an example of energy management required by a server that manages the power grid.This figure shows a modified version of the energy management method shown in Figure 2. Embodiments of this disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated. Figure 1 shows a schematic configuration of an energy management system according to an embodiment of this disclosure. Referring to Figure 1, the energy management system according to this embodiment comprises a power storage system 100 and a server 200 (EM server), and performs energy management of a power grid (PG). Server 200 is configured to communicate with a server 300 (TSO server) that manages the power grid (PG). "EM" stands for Energy Management. "TSO" stands for Transmission System Operator. The power grid (PG) is a power network constructed by power plants and transmission/distribution equipment. Server 300 includes a processor and memory device, monitors the status of the power grid (e.g., supply-demand balance and frequency), and requests energy management from Server 200. This maintains the power grid (PG) in a state where it can stably supply high-quality power. The power grid (PG) is, for example, an AC grid provided by a power company. The energy storage system 100 comprises a DC/AC conversion circuit 10, N SMRs 21-1 to 21-N (referred to as "SMR21" unless otherwise specified), N DC/DC conversion circuits 22-1 to 22-N (referred to as "DC/DC conversion circuit 22" unless otherwise specified), and N battery packs 23-1 to 23-N (referred to as "battery pack 23" unless otherwise specified). "SMR" stands for System Main Relay. SMR21, DC/DC conversion circuit 22, and battery pack 23 correspond to examples of "relay," "power conversion circuit," and "energy storage device" as described herein, respectively. The energy storage system 100 is controlled by a server 200. N is, for example, about 50. However, N may be any natural number greater than or equal to 2, and may be greater than or equal to 100. The energy storage system 100 may further include a leakage current detector (for example, a circuit breaker that automatically shuts off the current when a leakage current is detected), which is not shown in the figure. The battery packs 23-1 to 23-N are connected in parallel to each other. Each battery pack 23-1 to 23-N is equipped with SMRs 21-1 to 21-N and DC/DC conversion circuits 22-1 to 22-N, respectively. Each of the battery packs 23-1 to 23-N is configured to switch between energized and disconnected states according to commands from the server 200. Current can flow through a powered battery pack 23. Conversely, no current flows through a disconnected battery pack 23. In this embodiment, the SMR 21 is configured to switch the energized/disconnected state of the corresponding battery pack 23 according to commands from the server 200. The SMR 21 is located in the circuit connecting the DC/AC conversion circuit 10 and the DC/DC conversion circuit 22. The SMR 21 is, for example, an electromagnetic mechanical relay. The circuit is switched between disconnected and connected by the opening and closing of the SMR 21. The DC/AC conversion circuit 10 is configured to output AC power to the power grid PG according to commands from the server 200. The DC/AC conversion circuit 10 is also configured to convert the AC power input from the power grid PG into DC power and output it to each of the DC/DC conversion circuits 22-1 to 22-N. The DC/DC conversion circuit 22 is configured to transform the output voltage of the corresponding battery pack 23 according to commands from the server 200. Furthermore, the DC/DC conversion circuit 22 is configured to transform the DC power input from the DC/AC conversion circuit 10 and output it to the corresponding battery pack 23 according to commands from the server 200. In detail, when DC power is input from the battery pack 23 to the corresponding DC/DC conversion circuit 22, the DC/DC conversion circuit 22 outputs DC power to the DC/AC conversion circuit 10 according to the command from the server 200. The DC/AC conversion circuit 10 then outputs AC power to the power system PG according to the command from the server 200 (reverse power flow). On the other hand, when AC power is input from the power system PG to the DC/AC conversion circuit 10 (forward po