CN-121984163-A - In-phase SOC balance control method, control device, energy storage system and medium

CN121984163ACN 121984163 ACN121984163 ACN 121984163ACN-121984163-A

Abstract

The application discloses an in-phase SOC balance control method, a control device, an energy storage unit and a medium, wherein the method comprises the steps of monitoring the SOC of each energy storage battery pack in a target phase energy storage battery module under the condition that a three-phase energy storage battery module of the energy storage unit is in an operating state; under the condition that the SOC of the target phase energy storage battery module is balanced, the to-be-processed energy storage battery pack is determined from a plurality of target energy storage battery packs of the target phase energy storage battery module, the to-be-processed energy storage battery pack is switched from the running state to the hot standby state, and under the condition that the SOC of the target phase energy storage battery module is balanced, the to-be-processed energy storage battery pack is switched from the hot standby state to the running state. According to the method, under the condition that the in-phase SOC of the three-phase energy storage battery module of the energy storage unit is unbalanced, the energy storage battery pack with larger SOC deviation is controlled to temporarily withdraw from operation, so that the energy efficiency utilization rate of the energy storage unit is improved.

Inventors

LIU YOUWEI
CHEN XIAOBO

Assignees

宁德时代新能源科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20241031

Claims (16)

1. An in-phase SOC equalization control method, comprising: Under the condition that three-phase energy storage battery modules of an energy storage unit are in an operating state, monitoring the SOC of each energy storage battery pack in a target phase energy storage battery module, wherein the target phase energy storage battery module is at least one phase energy storage battery module in the three-phase energy storage battery modules; Under the condition that the target phase energy storage battery module is determined to have the unbalanced SOC, determining an energy storage battery pack to be processed from a plurality of target energy storage battery packs of the target phase energy storage battery module, wherein the SOC deviation value of the energy storage battery pack to be processed is larger than or equal to a first SOC deviation threshold value, the SOC deviation value is used for representing the difference value between the SOC of the energy storage battery pack to be processed and a target SOC average value, and the target SOC average value is the SOC average value of the plurality of target energy storage battery packs; Switching the energy storage battery pack to be processed from the running state to a hot standby state; and under the condition that the SOC of the target phase energy storage battery module is restored to be balanced, switching the energy storage battery pack to be processed from the hot standby state to the running state.
2. The method according to claim 1, wherein bypass switches corresponding to each energy storage battery group one by one are arranged in the three-phase energy storage battery module, and the bypass switches are used for bypassing the corresponding energy storage battery group when the bypass switches are closed; The switching the energy storage battery pack to be processed from the running state to the hot standby state comprises the following steps: and controlling a target bypass switch corresponding to the energy storage battery pack to be processed to be closed so as to enable the energy storage battery pack to be processed to be switched from the running state to the hot standby state.
3. The method according to claim 1, wherein an energy storage converter corresponding to each energy storage battery group one by one is arranged in the three-phase energy storage battery module, and the energy storage converter is used for performing charge and discharge control on the corresponding energy storage battery group according to the received modulation signal; The switching the energy storage battery pack to be processed from the running state to the hot standby state comprises the following steps: and the control target energy storage converter outputs the modulation signal with the modulation signal amplitude of zero to the energy storage battery pack to be processed, so that the energy storage battery pack to be processed is switched from the running state to the hot standby state.
4. A method according to any one of claims 1 to 3, wherein, in the event that it is determined that there is an SOC imbalance for the target phase energy storage battery module, prior to determining a pending energy storage battery pack from a plurality of target energy storage battery packs for the target phase energy storage battery module, the method further comprises: Determining an SOC deviation value of each target energy storage battery pack to obtain a plurality of SOC deviation values; determining whether the target phase energy storage battery module has SOC imbalance according to the plurality of SOC deviation values; The determining, in the case that it is determined that the target phase energy storage battery module has SOC imbalance, a to-be-processed energy storage battery pack from a plurality of target energy storage battery packs of the target phase energy storage battery module includes: and determining the energy storage battery packs to be processed from the target energy storage battery packs under the condition that the target phase energy storage battery modules are determined to have the unbalanced SOC according to the plurality of SOC deviation values.
5. The method of claim 4, wherein the determining whether there is SOC imbalance for the target phase energy storage battery module based on the plurality of SOC deviation values comprises: Determining a plurality of SOC deviation absolute values of the plurality of SOC deviation values, wherein each SOC deviation absolute value corresponds to one SOC deviation value; Determining that the target phase energy storage battery module has SOC imbalance when the SOC deviation absolute value greater than or equal to a second SOC deviation threshold value, which is less than the first SOC deviation threshold value, exists among the plurality of SOC deviation absolute values; And determining that the target phase energy storage battery module has no SOC imbalance when no SOC deviation absolute value greater than or equal to the second SOC deviation threshold value exists among the plurality of SOC deviation absolute values.
6. The method of claim 4, wherein the operating condition is a discharge condition, the plurality of SOC deviation values including a plurality of first sub-SOC deviation values, each first sub-SOC deviation value corresponding to a target energy storage battery; the determining an SOC deviation value for each target energy storage battery pack to obtain a plurality of SOC deviation values includes: And respectively calculating the target SOC average value minus the difference value of one SOC of each target energy storage battery pack to obtain a first sub-SOC deviation value so as to obtain a plurality of first sub-SOC deviation values.
7. The method of claim 6, wherein the determining the pending energy storage battery pack from the plurality of target energy storage battery packs if it is determined that there is SOC imbalance for the target phase energy storage battery module based on the plurality of SOC deviation values comprises: Under the condition that the target phase energy storage battery module is determined to have the unbalanced SOC according to the plurality of SOC deviation values, selecting a first sub-target SOC deviation value which is larger than or equal to the first SOC deviation threshold value from the plurality of first sub-SOC deviation values; And determining a target energy storage battery pack corresponding to the first sub-target SOC deviation value in the target energy storage battery packs as the energy storage battery pack to be processed.
8. The method of claim 7, wherein the selecting a first sub-target SOC deviation value from the plurality of first sub-SOC deviation values that is greater than or equal to the first SOC deviation threshold value if it is determined from the plurality of SOC deviation values that the target phase energy storage battery module has SOC imbalance comprises: under the condition that the target phase energy storage battery module is determined to have the SOC imbalance according to the plurality of SOC deviation values, selecting first N first sub-SOC deviation values which are larger than or equal to the first SOC deviation threshold value from the plurality of first sub-SOC deviation values as the first sub-target SOC deviation value, wherein N is smaller than or equal to the preset redundancy number of the target phase energy storage battery module.
9. The method of claim 4, wherein the operating state is a state of charge, the plurality of SOC deviation values including a plurality of second sub-SOC deviation values, each second sub-SOC deviation value corresponding to a target energy storage battery; the determining an SOC deviation value for each target energy storage battery pack to obtain a plurality of SOC deviation values includes: And respectively calculating the difference value of the target SOC average value subtracted from one SOC of each target energy storage battery pack to obtain a second sub-SOC deviation value so as to obtain a plurality of second sub-SOC deviation values.
10. The method of claim 9, wherein the determining the pending energy storage battery pack from the plurality of target energy storage battery packs if it is determined that there is SOC imbalance for the target phase energy storage battery module based on the plurality of SOC deviation values comprises: Under the condition that the target phase energy storage battery module is determined to have the unbalanced SOC according to the plurality of SOC deviation values, selecting a second sub-target SOC deviation value which is larger than or equal to the first SOC deviation threshold value from the plurality of second sub-SOC deviation values; and determining a target energy storage battery pack corresponding to the second sub-target SOC deviation value in the target energy storage battery packs as the energy storage battery pack to be processed.
11. The method of claim 10, wherein selecting a second sub-target SOC deviation value from the plurality of second sub-SOC deviation values that is greater than or equal to the first SOC deviation threshold value if it is determined from the plurality of SOC deviation values that the target phase energy storage battery module has SOC imbalance, comprises: under the condition that the target phase energy storage battery module is determined to have the SOC imbalance according to the plurality of SOC deviation values, the first N second sub-SOC deviation values which are larger than or equal to the first SOC deviation threshold value are selected from the plurality of second sub-SOC deviation values to serve as the second sub-target SOC deviation value, and N is smaller than or equal to the preset redundancy number of the target phase energy storage battery module.
12. The method according to any one of claims 1 to 11, wherein the method further comprises, in the event that the SOC of the target phase energy storage battery module is restored to equilibrium, before switching the pending energy storage battery pack from the hot standby state to the operating state: Determining a current phase shift angle of a current target energy storage battery pack according to the current number of the current target energy storage battery packs, wherein the current target energy storage battery pack is a target energy storage battery pack in the running state in the plurality of target energy storage battery packs; and controlling the operation of the current target energy storage battery pack according to the current phase shift angle.
13. The method according to any one of claims 1 to 12, wherein, in the case where the SOC of the target phase energy storage battery module is restored to be balanced, after switching the to-be-processed energy storage battery pack from the hot standby state to the operating state, the method further comprises: determining target phase shift angles of the plurality of target energy storage battery packs according to the target number of the plurality of target energy storage battery packs; And controlling the operation of the plurality of target energy storage battery packs according to the target phase shift angle.
14. An in-phase SOC equalization control device, comprising: The monitoring module is used for monitoring the SOC of each energy storage battery pack in a target phase energy storage battery module under the condition that three-phase energy storage battery modules of the energy storage unit are in an operating state, wherein the target phase energy storage battery module is at least one phase energy storage battery module in the three-phase energy storage battery modules; The first determining module is used for determining an energy storage battery pack to be processed from a plurality of target energy storage battery packs of the target phase energy storage battery module under the condition that the target phase energy storage battery module is determined to have the unbalanced SOC, the SOC deviation value of the energy storage battery pack to be processed is larger than or equal to a first SOC deviation threshold value, the SOC deviation value is used for representing the difference value between the SOC of the energy storage battery pack to be processed and a target SOC average value, and the target SOC average value is the SOC average value of the plurality of target energy storage battery packs; The first switching module is used for switching the energy storage battery pack to be processed from the running state to a hot standby state; And the second switching module is used for switching the energy storage battery pack to be processed from the hot standby state to the running state under the condition that the SOC of the target phase energy storage battery module is restored to be balanced.
15. An energy storage system, comprising: A memory; One or more processors coupled with the memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, the one or more applications configured to perform the method of any of claims 1-13.
16. A computer readable storage medium having stored therein program code which is callable by a processor to perform the method of any one of claims 1 to 13.

Description

In-phase SOC balance control method, control device, energy storage system and medium Technical Field The application belongs to the technical field of energy storage, and particularly relates to an in-phase SOC balance control method, a control device, an energy storage system and a medium. Background The energy storage unit is a system for storing and releasing electric energy, and aims to balance power supply and demand and improve the stability of a power grid. The three-phase energy storage battery module is an important component of the energy storage unit, each phase energy storage battery module is composed of a plurality of energy storage battery packs, and each phase energy storage battery module is used for processing one phase of current in three-phase currents of the power system. After the energy storage unit is operated for a period of time, the states of Charge (SOC) of the plurality of energy storage battery packs in the phases of the three-phase energy storage battery module are liable to be unbalanced for various reasons. At present, under the condition that the in-phase SOC of the three-phase energy storage battery module is unbalanced in the operation process of the energy storage unit, a short-plate effect easily occurs in the operation process of the energy storage unit, so that the energy efficiency utilization rate of the energy storage unit is lower. Disclosure of Invention In view of the above, the embodiments of the present application provide a method, a device, an energy storage system and a medium for controlling in-phase SOC equalization, so as to overcome the above problems in the prior art. In a first aspect, an embodiment of the present application provides a method for controlling in-phase SOC equalization, including: Under the condition that three-phase energy storage battery modules of the energy storage unit are in an operating state, monitoring the SOC of each energy storage battery pack in a target phase energy storage battery module, wherein the target phase energy storage battery module is at least one phase energy storage battery module in the three-phase energy storage battery modules; Under the condition that the target phase energy storage battery module is determined to have the unbalanced SOC, determining an energy storage battery pack to be processed from a plurality of target energy storage battery packs of the target phase energy storage battery module, wherein the SOC deviation value of the energy storage battery pack to be processed is larger than or equal to a first SOC deviation threshold value, and the SOC deviation value is used for representing the difference value between the SOC of the energy storage battery pack to be processed and a target SOC average value, and the target SOC average value is the SOC average value of the plurality of target energy storage battery packs; Switching the energy storage battery pack to be processed from an operation state to a hot standby state; and under the condition that the SOC of the target phase energy storage battery module is restored to be balanced, switching the energy storage battery pack to be processed from the hot standby state to the running state. According to the scheme provided by the application, in the operation process of the energy storage unit, under the condition that the in-phase SOC of the three-phase energy storage battery module of the energy storage unit is unbalanced, the energy storage battery pack with larger SOC deviation is controlled to temporarily exit the operation until the operation of the energy storage battery pack which has temporarily exited the operation is restored under the condition that the in-phase SOC of the three-phase energy storage battery module is balanced, the occurrence of a short-circuit effect can be restrained, and the energy efficiency utilization rate of the energy storage unit is improved. In some alternative embodiments, bypass switches corresponding to each energy storage battery group one by one are arranged in the three-phase energy storage battery modules, and the bypass switches are used for bypassing the corresponding energy storage battery groups under the condition of closing; switching the energy storage battery pack to be processed from the running state to the hot standby state comprises the following steps: And controlling a target bypass switch corresponding to the energy storage battery pack to be processed to be closed so as to enable the energy storage battery pack to be processed to be switched from the running state to the hot standby state. According to the scheme provided by the embodiment, the temporary withdrawal of the to-be-processed energy storage battery pack is controlled based on the target bypass switch, and under the condition that the to-be-processed energy storage battery pack is withdrawn from operation, the rest target energy storage battery pack in the target phase energy storage battery module normally operates, so th