EP-4738641-A1 - BATTERY PACK AND ENERGY STORAGE SYSTEM

Abstract

A battery module and an energy storage system are provided. The battery module includes a battery pack, a DC/DC converter, a controller, and a voltage regulator circuit. The voltage regulator circuit includes a resistor, a capacitor, a first switch, and a second switch. A positive end of the DC/DC converter and one end of the capacitor are connected to a positive electrode of the battery pack through the first switch, a negative end of the DC/DC converter and the other end of the capacitor are connected to a negative electrode of the battery pack through the resistor, and the negative end and the other end of the battery-side capacitor are connected to the negative electrode of the battery pack through the second switch. The controller is configured to control the first switch to be turned on, control the second switch to be turned on after a preset condition is met, and control the DC/DC converter, where a voltage at the two ends of the capacitor when the preset condition is met is greater than a voltage at the two ends of the capacitor when the preset condition is not met. The second switch is turned on after the preset condition is met, so that a control delay of the DC/DC converter can be reduced.

Inventors

• WENG, Sai
• WU, YIHONG
• GUO, Haibin

Assignees

• Huawei Digital Power Technologies Co., Ltd.

Dates

Publication Date

20260506

Application Date

20240201

Claims (5)

1. A battery module, comprising: a battery pack, a direct current to direct current DC/DC converter, a controller, and a voltage regulator circuit, wherein the voltage regulator circuit comprises a resistor, a capacitor, a first switch, and a second switch, a positive end of the DC/DC converter and one end of the capacitor are connected to a positive electrode of the battery pack through the first switch, a negative end of the DC/DC converter and the other end of the capacitor are connected to a negative electrode of the battery pack through the resistor, and the negative end and the other end of the battery-side capacitor are connected to the negative electrode of the battery pack through the second switch; and the controller is configured to: control the first switch to be turned on; and when a preset condition is met, control the second switch to be turned on, and control the DC/DC converter, wherein a voltage at the two ends of the capacitor when the preset condition is met is greater than a voltage at the two ends of the capacitor when the preset condition is not met.
2. The battery module according to claim 1, wherein the preset condition comprises any one of the following conditions: a voltage value at the two ends of the capacitor is greater than or equal to a first threshold; a difference between a voltage value of the battery pack and the voltage value at the two ends of the capacitor is less than or equal to a second threshold; and duration starting from time at which the first switch is turned on is greater than or equal to a third threshold.
3. The battery module according to claim 1 or 2, wherein the controller is further configured to: obtain the voltage value of the battery pack; and determine the preset condition based on the voltage value of the battery pack.
4. The battery module according to any one of claims 1 to 3, wherein the battery module further comprises an auxiliary power supply, and the auxiliary power supply supplies electric power to the controller in response to an excitation signal; and the controller is further configured to send a response instruction after the second switch is turned on, wherein the response instruction instructs to stop sending the excitation signal.
5. An energy storage system, comprising one or more battery clusters connected in parallel, wherein each battery cluster comprises a plurality of battery modules according to any one of claims 1 to 4, and the plurality of battery modules are connected in series.

Description

This application claims priority to Chinese Patent Application No. 202310965046.6, filed with the China National Intellectual Property Administration on August 1, 2023 and entitled "BATTERY MODULE AND ENERGY STORAGE SYSTEM", which is incorporated herein by reference in its entirety. TECHNICAL FIELD Embodiments of this application relate to the field of electric power technologies, and in particular, to a battery module and an energy storage system. BACKGROUND In the fields of energy storage and the like, a direct current to direct current (direct current to direct current, DC/DC) converter is usually disposed in a battery module, and the DC/DC converter performs power conversion, for example, charging or discharging, on a battery pack included in the battery module. To avoid damage to the DC/DC converter caused by voltage fluctuation of the battery pack, a voltage regulator circuit is usually disposed in the battery module. To be specific, a positive end and a negative end of the DC/DC converter are connected to two electrodes of the battery pack through the voltage regulator circuit, the voltage regulator circuit includes a capacitor, and the capacitor and the DC/DC converter are connected in parallel at the two electrodes of the battery pack through the voltage regulator circuit. To enable the voltage regulator circuit to operate normally, before the DC/DC converter controls a battery, or in other words, before a control instruction used to control the DC/DC converter is received, the voltage regulator circuit needs to be conducted, so that the capacitor completes charging. In the conventional technology, to ensure that a capacitor reliably completes charging, before a DC/DC converter is controlled, a voltage regulator circuit needs to be conducted in advance for long time. As a result, a control delay of the DC/DC converter is long. SUMMARY Embodiments of this application provide a battery module and an energy storage system, to reduce a control delay of a DC/DC converter. According to a first aspect, a battery module is provided. The battery module includes a battery pack, a DC/DC converter, a controller, and a voltage regulator circuit. The voltage regulator circuit includes a resistor, a capacitor, a first switch, and a second switch. A positive end of the DC/DC converter and one end of the capacitor are connected to a positive electrode of the battery pack through the first switch, a negative end of the DC/DC converter and the other end of the capacitor are connected to a negative electrode of the battery pack through the resistor, and the negative end and the other end of the battery-side capacitor are connected to the negative electrode of the battery pack through the second switch. The controller is configured to control the first switch to be turned on. After a preset condition is met, the controller controls the second switch to be turned on, where a voltage at the two ends of the capacitor after the preset condition is met is greater than a voltage at the two ends of the capacitor before the preset condition is met. The controller controls the DC/DC converter according to a control instruction. The preset condition is used to determine whether a voltage value at the two ends of the capacitor meets a soft-start condition. In this case, that "the voltage value at the two ends of the capacitor meets the soft-start condition" or "the preset condition is met" may be understood as follows: A voltage value of the capacitor increases to a voltage value that enables the capacitor to effectively regulate and filter a current from the battery pack; or that "the voltage value at the two ends of the capacitor does not meet the soft-start condition" or "the preset condition is not met" may be understood as follows: A voltage value of the capacitor does not meet a requirement of voltage regulation processing and filtering processing. That is, in embodiments of this application, determining whether the preset condition is met is equivalent to determining whether the voltage value at the two ends of the capacitor meets the soft-start condition. That is, when the preset condition is met, the charged capacitor can perform effective voltage regulation processing on the current from the battery pack, thereby effectively protecting the DC/DC converter. Therefore, compared with the conventional technology, this application can save time for waiting for the capacitor to complete charging, and reduce the control delay of the DC/DC converter. In an implementation, the controller is further configured to: receive the control instruction dedicated to the DC/DC converter, and control the first switch to be turned on in response to the control instruction. In the conventional technology, to protect a DC/DC converter, a controller needs to turn on a first switch and a second switch before receiving a control instruction dedicated to the DC/DC converter, to complete charging of a capacitor. As a result, although control on th