KR-20260062831-A - BATTERY SYSTEM

Abstract

The battery system comprises a plurality of battery packs connected in parallel to each other in an external system and a plurality of DC/DC converters. Each DC/DC converter includes a boost circuit that boosts the DC voltage of the corresponding battery pack and outputs the boosted voltage to the external system, and a voltage detector that detects the boosted voltage. In a correction mode, the control device controls the boost circuit of a first DC/DC converter selected from the plurality of DC/DC converters, while stopping the operation of the boost circuits of the remaining DC/DC converters. The control device corrects the voltage detector of at least one DC/DC converter among the plurality of DC/DC converters based on the detected value of the voltage detector of the plurality of DC/DC converters.

Inventors

• 하부 마사카즈

Assignees

• 도요타 지도샤（주）

Dates

Publication Date

20260507

Application Date

20250925

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 DC/DC converters is, A boost circuit that boosts the DC voltage of the corresponding battery pack and outputs the boosted voltage, which is the voltage after boosting, to the external system, and It includes a voltage detector for detecting the above-mentioned boost voltage, and The battery system is configured to execute a normal operation mode for performing charging and discharging with the external system and a correction mode for correcting the voltage detector. In the above normal operating mode, the control device controls the boost circuit using the detection value of the voltage detector for each of the plurality of DC/DC converters, and In the above correction mode, the control device, While controlling the boost circuit of the first DC/DC converter selected from the plurality of DC/DC converters, the operation of the boost circuit of the remaining DC/DC converters is stopped, and A battery system that corrects the voltage detector of at least one of the plurality of DC/DC converters based on the detection value of the voltage detector of the plurality of DC/DC converters during the control of the boost circuit of the first DC/DC converter.
2. In Article 1, During the control of the boost circuit of the first DC/DC converter, the control device, Based on the detection value of the voltage detector of the plurality of DC/DC converters, the true value of the boost voltage in the boost circuit of the first DC/DC converter is estimated, and A battery system that calibrates the voltage detectors of at least one DC/DC converter using the estimated true value.
3. 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 The above control device is a battery system that executes the correction mode while the power converter is stopped operating.
4. In any one of paragraphs 1 to 3, A battery system in which, in the above normal operating mode, the control device performs droop control of the boost circuit based on the detection value of the voltage detector in each of the plurality of DC/DC converters.

Description

Battery System The present disclosure relates to a battery system, and more specifically, to a technique for calibrating a voltage detector disposed in a battery system comprising a plurality of boost circuits. Japanese Patent Publication No. 2010-259265 discloses an automobile having a first battery and a second battery connected in parallel to a driving circuit that drives an electric motor, and a first boost circuit and a second boost circuit formed corresponding to the first battery and the second battery, respectively, and boosting the voltage of the corresponding battery and supplying it to the driving circuit. The above-described vehicle further comprises a first system main relay for connecting/disconnecting a first battery and a first boost circuit, a second system main relay for connecting/disconnecting a second battery and a second boost circuit, a voltage detector for detecting the voltage on the second battery side of the second boost circuit, and an abnormality determination means for determining an abnormality of the second boost circuit. The abnormality determination means determines that an abnormality has occurred in which a transistor constituting the upper arm of the second boost circuit is stuck on when the detection value of the voltage detector is above a threshold value while the first system main relay is turned on and the second system main relay is turned off. In a configuration having multiple boost circuits, such as the automobile described in Japanese Patent Publication No. 2010-259265, it is common for a voltage detector to be formed for each boost circuit to detect the boosted voltage, which is the voltage after boosting. Therefore, the entire battery system is configured to have multiple voltage detectors. If an error occurs in the output of the multiple voltage detectors, there is a risk that the boosted voltage cannot be accurately controlled. For this reason, it becomes important to perform correction of the multiple voltage detectors. However, Japanese Patent Publication No. 2010-259265 does not mention the correction of voltage detectors at all. 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, in which similar reference numerals indicate similar elements: 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 the calibration mode of a battery system; Figure 4 is a flowchart illustrating the sequence of correction processing of a voltage 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 given 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). During the operation of the battery system (100), if 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 a