CN-121984171-A - Energy balance control method, device, equipment and medium of energy storage system

CN121984171ACN 121984171 ACN121984171 ACN 121984171ACN-121984171-A

Abstract

The application discloses an energy balance control method, device, equipment and medium of an energy storage system, which belong to the technical field of energy storage and comprise the steps of determining average SOC of all battery packs in the energy storage system to obtain average SOC when the energy storage system needs to perform energy balance, wherein the energy storage system comprises a high-voltage box and a plurality of battery packs connected with the high-voltage box in series, a BCU main control board is arranged in the high-voltage box, each battery pack is provided with a bidirectional energy converter, positive poles and negative poles of the battery packs are respectively connected together, determining expected running current of the target battery pack when the energy storage system reaches an energy balance state according to the average SOC, and regulating and controlling the running state of the target battery pack by utilizing the bidirectional energy converters in the target battery pack based on the expected running current of the target battery pack until the difference value between the SOC of the target battery pack and the average SOC is smaller than a first preset threshold value. The method can reduce logic complexity and required cost investment when the energy storage system is subjected to balanced control.

Inventors

LU ZETONG
LI RONGWEI
PAN DONGHUA
JIA MEI
ZHOU BIN

Assignees

固德威技术股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260210

Claims (10)

1. An energy balance control method of an energy storage system is characterized by comprising the following steps: When an energy storage system needs to perform energy balance, determining the SOC of all battery packs in the energy storage system, and determining the average SOC of all battery packs in the energy storage system according to the SOC of all battery packs to obtain an average SOC; the energy storage system comprises a high-voltage box and a plurality of battery packs which are connected with the high-voltage box and are connected in series, a BCU main control board is arranged in the high-voltage box, a bidirectional energy converter is arranged in each battery pack, and the anodes and the cathodes of the battery packs are respectively connected together through the bidirectional energy converters arranged in the battery packs; determining expected running current of a target battery pack when the energy storage system reaches an energy balance state according to the average value SOC, wherein the target battery pack is any battery pack in the energy storage system; And regulating and controlling the running state of the target battery pack by utilizing a bidirectional energy converter in the target battery pack based on the expected running current of the target battery pack until the difference value between the SOC of the target battery pack and the average value SOC is smaller than a first preset threshold value.
2. The method of claim 1, wherein the bi-directional energy converter provided in each battery pack is a DAB circuit.
3. The energy balance control method of an energy storage system of claim 1, further comprising: determining the SOC corresponding to all battery packs in the energy storage system to obtain an SOC set; Judging whether the difference value between two SOCs in the SOC set is larger than a second preset threshold value or not; If yes, the energy storage system is judged to need energy equalization.
4. The method for controlling energy balance of an energy storage system according to claim 1, wherein determining the SOC of all battery packs in the energy storage system and determining the average SOC of all battery packs in the energy storage system according to the SOC of all battery packs to obtain the average SOC comprises: determining the maximum SOC of the target battery pack and the minimum SOC of the target battery pack according to the minimum SOC of the energy storage system, the maximum cell voltage of the target battery pack, the minimum cell voltage of the target battery pack, the maximum cell voltage of the energy storage system and the minimum cell voltage of the energy storage system; when the energy storage system is in a charging state, determining the average SOC of all battery packs in the energy storage system according to the maximum SOC of the target battery pack to obtain the average SOC; And when the energy storage system is in a discharging state, determining the average SOC of all battery packs in the energy storage system according to the minimum SOC of the target battery pack to obtain the average SOC.
5. The method of claim 4, wherein determining the expected operating current of the target battery pack when the energy storage system reaches an energy balance state according to the average SOC comprises: When the energy storage system is in a charging state, a difference value between the maximum SOC of the target battery pack and the average value SOC is obtained, and a first difference value is obtained; Determining the expected running time when the energy storage system reaches an energy balance state in a charging state according to the first difference value, the ideal balance time and the ideal balance rate of the energy storage system, and obtaining a first balance time; Determining an expected running current of the target battery pack when the energy storage system reaches an energy balance state in a charging state according to the first balance time and the first difference value; When the energy storage system is in a discharging state, a difference value between the minimum SOC of the target battery pack and the average value SOC is obtained, and a second difference value is obtained; determining expected operation time when the energy storage system reaches an energy balance state in a discharge state according to the second difference value, and the ideal balance time and the ideal balance rate of the energy storage system, so as to obtain second balance time; And determining the expected running current of the target battery pack when the energy storage system reaches an energy balance state in a discharging state according to the second balance time and the second difference value.
6. The method of claim 5, wherein adjusting the operating state of the target battery pack with the bidirectional energy converter in the target battery pack based on the expected operating current of the target battery pack until the difference between the SOC of the target battery pack and the average SOC is less than a first preset threshold, comprises: Adding expected running currents corresponding to all battery packs when the energy storage system reaches an energy balance state to obtain a current addition value, and judging whether the current addition value is in a preset range or not; And if so, regulating and controlling the running state of the target battery pack by using a bidirectional energy converter in the target battery pack by taking the expected running current of the target battery pack as a reference until the difference value between the SOC of the target battery pack and the average value SOC is smaller than a first preset threshold value.
7. The method for controlling energy balance of an energy storage system according to claim 6, wherein after said determining whether the current added value is within a preset range, further comprising: If not, the expected running current of the target battery pack is adjusted by using the current adding value, the expected running current of the target battery pack when the energy storage system reaches the energy balance state is obtained again, the expected running currents corresponding to all battery packs when the energy storage system reaches the energy balance state are added again, the current adding value is obtained, and whether the current adding value is in a preset range is judged.
8. An energy balance control device of an energy storage system, comprising: the system comprises an energy storage system, a mean value SOC determining module, a control module and a control module, wherein the energy storage system comprises a high-voltage box and a plurality of battery packs connected in series with each other, the high-voltage box is internally provided with a BCU main control board, each battery pack is internally provided with a bidirectional energy converter, and the anodes and the cathodes of the battery packs are respectively connected together through the bidirectional energy converters arranged in the battery packs; The expected current determining module is used for determining expected running current of a target battery pack when the energy storage system reaches an energy balance state according to the average value SOC, wherein the target battery pack is any battery pack in the energy storage system; And the running state regulating and controlling module is used for regulating and controlling the running state of the target battery pack by utilizing the bidirectional energy converter in the target battery pack based on the expected running current of the target battery pack until the difference value between the SOC of the target battery pack and the average value SOC is smaller than a first preset threshold value.
9. An electronic device, comprising: A memory for storing a computer program; a processor for implementing the steps of a method for energy balance control of an energy storage system according to any one of claims 1 to 7 when executing said computer program.
10. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements the steps of a method of energy balance control of an energy storage system according to any of claims 1 to 7.

Description

Energy balance control method, device, equipment and medium of energy storage system Technical Field The present invention relates to the field of energy storage technologies, and in particular, to a method, an apparatus, a device, and a medium for controlling energy balance of an energy storage system. Background In an energy storage system, a desired high voltage is usually achieved through a series connection of a plurality of battery packs, then the plurality of battery packs are assembled into a battery cluster, and the power storage requirements of different capacities are met through the series connection or the parallel connection of the plurality of battery clusters. In an energy storage system composed of a plurality of battery packs connected in series or in parallel, the maximum circulation capacity of the whole energy storage system is affected by the short plate effect of the single battery pack. Therefore, there is a need for balancing control of energy storage systems and thereby improving the barrel effect of the energy storage systems. In the prior art, two methods are generally used to perform equalization control on an energy storage system. One is to perform energy balance control on the energy storage system through an external relay switching matrix, but the cost input required by the method is too high. The other method is to control the battery cells in the battery pack to achieve the purpose of balancing and controlling the energy storage system, but the number of the battery cells in the energy storage system is huge, so that balancing and controlling logic of the energy storage system is extremely complex. Currently, there is no more effective solution to this technical problem. Therefore, how to reduce the logic complexity and the required cost investment in the balanced control of the energy storage system is a technical problem to be solved by those skilled in the art. Disclosure of Invention In view of the above, the present invention is directed to a method, apparatus, device and medium for controlling energy balance of an energy storage system, so as to reduce the logic complexity and cost input required for controlling the energy storage system in balance. The specific scheme is as follows: in order to solve the technical problems, the invention provides an energy balance control method of an energy storage system, which comprises the following steps: When the energy storage system needs to perform energy balance, determining the SOC of all battery packs in the energy storage system, and determining the average SOC of all battery packs in the energy storage system according to the SOC of all battery packs to obtain an average SOC; the energy storage system comprises a high-voltage box and a plurality of battery packs which are connected with the high-voltage box and are connected in series, a BCU main control board is arranged in the high-voltage box, a bidirectional energy converter is arranged in each battery pack, and the anodes and the cathodes of the battery packs are respectively connected together through the bidirectional energy converters arranged in the battery packs; determining expected running current of a target battery pack when the energy storage system reaches an energy balance state according to the average value SOC, wherein the target battery pack is any battery pack in the energy storage system; And regulating and controlling the running state of the target battery pack by utilizing a bidirectional energy converter in the target battery pack based on the expected running current of the target battery pack until the difference value between the SOC of the target battery pack and the average value SOC is smaller than a first preset threshold value. Preferably, the bi-directional energy converter provided in each battery pack is embodied as a DAB circuit. Preferably, the method further comprises: determining the SOC corresponding to all battery packs in the energy storage system to obtain an SOC set; Judging whether the difference value between two SOCs in the SOC set is larger than a second preset threshold value or not; If yes, the energy storage system is judged to need energy equalization. Preferably, the determining the SOC of all the battery packs in the energy storage system, and determining the average SOC of all the battery packs in the energy storage system according to the SOC of all the battery packs, to obtain the average SOC includes: determining the maximum SOC of the target battery pack and the minimum SOC of the target battery pack according to the minimum SOC of the energy storage system, the maximum cell voltage of the target battery pack, the minimum cell voltage of the target battery pack, the maximum cell voltage of the energy storage system and the minimum cell voltage of the energy storage system; when the energy storage system is in a charging state, determining the average SOC of all battery packs in the energy storage system acc