KR-20260062808-A - BATTERY SYSTEM

Abstract

Each battery pack includes first and second current detectors for detecting current flowing through a battery stack. In one battery pack, if the detection values of the first and second current detectors do not match, the control device operates a DC/DC converter corresponding to each battery pack to transfer power between the battery pack and another battery pack. During the operation of the DC/DC converter, the control device compares the detection values of the first and second current detectors in the one battery pack with the detection value of the first current detector in the other battery pack, and selects a normal current detector from the first and second current detectors in the one battery pack.

Inventors

• 하부 마사카즈

Assignees

• 도요타 지도샤（주）

Dates

Publication Date

20260507

Application Date

20250708

Priority Date

20241029

Claims (4)

1. As a battery system that performs charging and discharging between an external system, A plurality of battery packs connected in parallel to each other in the above external system, and A plurality of DC/DC converters formed corresponding to each of the plurality of battery packs, each of which performs DC voltage conversion between the corresponding battery pack and the external system, and A control device for controlling the plurality of DC/DC converters described above is provided, Each of the above plurality of battery packs is, Battery stack and, A first current detector for detecting the current flowing through the battery stack, and It includes a second current detector connected in series with the first current detector to detect the current flowing through the battery stack, and In any one of the plurality of battery packs, if the detection value of the first current detector and the detection value of the second current detector do not match, the control device, To transfer power between any one battery pack and another battery pack, a DC/DC converter corresponding to each of the said one battery pack and the other battery pack is operated, and A battery system that, during the operation of the DC/DC converter, selects a normal current detector from the first and second current detectors in the one battery pack by comparing the detection values of the first and second current detectors in the one battery pack with the detection value of the first current detector in the other battery pack.
2. In Article 1, If the detection value of the first current detector in any one of the above battery packs matches the detection value of the first current detector in the other one battery pack, the control device selects the first current detector in any one of the above battery packs as the normal current detector, and A battery system in which, when the detection value of the second current detector in any one of the above battery packs matches the detection value of the first current detector in the other one battery pack, the control device selects the second current detector in any one of the above battery packs as the normal current detector.
3. In Article 1 or Article 2, A battery system in which, when the above normal current detector is selected, the control device operates the DC/DC converter corresponding to any one of the battery packs using the detection value of the above normal current detector.
4. In Article 1, The above external system includes a power conversion device that performs bidirectional power conversion between the power grid and the battery system, and In any one of the plurality of battery packs, if the detection value of the first current detector and the detection value of the second current detector do not match, the power converter stops operating, and A battery system in which the control device operates the DC/DC converter corresponding to each of the one battery pack and the other battery pack during the shutdown of the power converter.

Description

Battery System The present disclosure relates to a battery system, and more specifically, to a technique for detecting an abnormality in a current detector disposed in a battery system comprising a plurality of battery packs connected in parallel. Japanese Patent Publication No. 2020-16493 discloses a current measuring device equipped with three or more current sensors for measuring the current of a battery. The current measuring device has an average value calculation unit that calculates the average value of the measurements of three or more current sensors and sets the calculated average value as the current of the battery. In addition, the current measuring device has a fault determination unit that compares the measurements of three or more current sensors with each other and determines that a current sensor is faulty if it measures a value where the difference between the measured value and another current sensor among the three or more current sensors is greater than or equal to a threshold value. The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein similar reference numerals denote similar elements, and FIG. 1 is a schematic diagram of a battery system according to an embodiment of the present disclosure; FIG. 2 is a diagram showing the configuration of a battery module; FIG. 3 is a diagram illustrating an abnormality detection mode of a battery system; FIG. 4 is a flowchart for explaining the sequence of abnormal detection processing of a current detector by a control device; and Figure 5 is a flowchart illustrating a modified example of the abnormal detection processing of a current detector by a control device. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, identical or substantial parts in the drawings are denoted by the same reference numerals, and their descriptions are not repeated. FIG. 1 is a schematic diagram of a battery system according to the present embodiment. As shown in FIG. 1, the battery system (100) according to the present embodiment is connected to an external system (2) by a power line (L). The battery system (100) can be supplied with power from the external system (2) and can also be discharged to the external system (2). The battery system (100) is applied, for example, to a stationary energy storage system installed at a consumer. The battery system (100) comprises a plurality of battery modules (BM1 to BM3), a plurality of sub-relays (SR1 to SR3), and a control device (30). Hereinafter, the battery modules (BM1 to BM3) are collectively referred to as "battery modules (BM)" and the sub-relays (SR1 to SR3) are collectively referred to as "sub-relays (SR)". In the example of FIG. 1, the battery system (100) comprises three battery modules (BM) and three sub-relays (SR), but the number of battery modules (BM) and sub-relays (SR) is arbitrary and may be single. A plurality of battery modules (BM1 to BM3) are connected in parallel to each other with respect to an external system (2). A plurality of sub-relays (SR1 to SR3) are formed corresponding to each of the plurality of battery modules (BM1 to BM3). The sub-relays (SR) are controlled by a control device (30) to connect or disconnect the corresponding battery module (BM) and the external system (2). In one phase, when the battery system (100) starts up, the sub-relays (SR) are turned on, and the corresponding battery module (BM) is connected to the external system (2). When a failure occurs in the corresponding battery module (BM), the sub-relays (SR) are turned off, and the corresponding battery module (BM) is disconnected from the external system (2). The battery module (BM1) includes a plurality of battery packs (BA to BC) and a plurality of DC/DC converters (1A to 1C). Hereinafter, the battery packs (BA to BC) are collectively referred to as "battery packs (B)" and the DC/DC converters (1A to 1C) are collectively referred to as "DC/DC converters (1)". In the example of FIG. 1, the battery module (BM1) includes three battery packs (B) and three DC/DC converters (1), but the number of each of the battery packs (B) and DC/DC converters (1) may be multiple. Multiple battery packs (BA to BC) are connected in parallel to each other to an external system (2) through a sub-relay (SR1). A battery pack (B) includes a battery stack. A plurality of DC/DC converters (1A to 1C) are formed corresponding to a plurality of battery packs (BA to BC), respectively. The DC/DC converter (1) controls the charging and discharging of the corresponding battery pack (B) by performing DC voltage conversion between the corresponding battery pack (B) and the external system (2). Specifically, the DC/DC converter (1) is configured to include a boost circuit and a buck circuit. The boost circuit controls the discharge of the correspondin