CN-121984164-A - Energy storage unit SOC balance control method and device, energy storage system and medium thereof

CN121984164ACN 121984164 ACN121984164 ACN 121984164ACN-121984164-A

Abstract

The application discloses an energy storage unit SOC balance control method and device, an energy storage system and medium, wherein the method comprises the steps of determining the inter-phase SOC difference value of three-phase energy storage battery modules of the energy storage unit under the condition that the three-phase energy storage battery modules are in an operating state; and under the condition that the target inter-phase SOC difference value is larger than or equal to a preset threshold value, controlling the first phase energy storage battery module corresponding to the target inter-phase SOC difference value to charge the second phase energy storage battery module corresponding to the target inter-phase SOC difference value until the target inter-phase SOC difference value is smaller than the preset threshold value. According to the method, under the condition that the inter-phase SOC difference value of the three-phase energy storage battery modules of the energy storage unit is large, the first-phase energy storage battery module corresponding to the large inter-phase SOC difference value is controlled to charge the second-phase energy storage battery module until the three-phase SOCs of the three-phase energy storage battery modules reach balance, and the service life of the energy storage unit is prolonged.

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 (11)

1. The SOC balance control method for the energy storage unit is characterized by comprising the following steps of: Under the condition that a three-phase energy storage battery module of an energy storage unit is in an operating state, determining the inter-phase SOC difference value of the three-phase energy storage battery module; And under the condition that the target inter-phase SOC difference value is larger than or equal to a preset threshold value, controlling a first phase energy storage battery module corresponding to the target inter-phase SOC difference value to charge a second phase energy storage battery module corresponding to the target inter-phase SOC difference value until the target inter-phase SOC difference value is smaller than the preset threshold value, wherein the target inter-phase SOC difference value comprises at least one of the inter-phase SOC difference values.
2. The method for controlling SOC balance of an energy storage unit according to claim 1, wherein before the first phase energy storage battery module corresponding to the target inter-phase SOC difference value is controlled to charge the second phase energy storage battery module corresponding to the target inter-phase SOC difference value, the method for controlling SOC balance of an energy storage unit further comprises: The energy storage unit is controlled to be disconnected from the electric connection with the power grid; The controlling the first phase energy storage battery module corresponding to the target inter-phase SOC difference value to charge the second phase energy storage battery module corresponding to the target inter-phase SOC difference value includes: And under the condition that the energy storage unit is controlled to be disconnected from the electric connection with the power grid, the first phase energy storage battery module is controlled to charge the second phase energy storage battery module.
3. The method according to claim 2, wherein a load switch is provided between the first phase energy storage battery module and the second phase energy storage battery module, and before the first phase energy storage battery module is controlled to charge the second phase energy storage battery module, the method further comprises: Controlling the load switch to be switched from an open state to a closed state; The controlling the first phase energy storage battery module to charge the second phase energy storage battery module includes: And under the condition that the load switch is in the closed state, controlling the first phase energy storage battery module to charge the second phase energy storage battery module.
4. The energy storage unit SOC equalization control method of claim 2 or 3, wherein the energy storage unit SOC equalization control method is further comprised of: Acquiring a neutral period of the energy storage unit, wherein the neutral period is used for representing that the power grid and the energy storage unit have no energy exchange; The controlling the energy storage unit to disconnect from electrical connection with a power grid includes: And under the condition that the current moment is in the neutral period, controlling the energy storage unit to disconnect the electric connection with the power grid.
5. The energy storage unit SOC balance control method according to any one of claims 1 to 4, wherein before the first phase energy storage battery module corresponding to the target inter-phase SOC difference value is controlled to charge the second phase energy storage battery module corresponding to the target inter-phase SOC difference value, the energy storage unit SOC balance control method further includes: determining a first phase energy storage battery module of a first phase SOC corresponding to the target inter-phase SOC difference as the first phase energy storage battery module; and determining a one-phase energy storage battery module of a second phase SOC corresponding to the target inter-phase SOC difference as the second phase energy storage battery module, wherein the first phase SOC is larger than the second phase SOC.
6. The energy storage unit SOC balance control method according to any of claims 1 to 5, wherein the determining, in a case where a three-phase energy storage battery module of an energy storage unit is in an operating state, respective inter-phase SOC differences of the three-phase energy storage battery module includes: under the condition that three-phase energy storage battery modules of an energy storage unit are in an operating state, determining three-phase SOC of the three-phase energy storage battery modules, wherein each phase SOC corresponds to one phase energy storage battery module; And determining a phase-to-phase SOC difference value according to any two-phase SOC in the three-phase SOCs respectively to obtain the phase-to-phase SOC difference value.
7. The method according to claim 6, wherein determining the three-phase SOC of the three-phase energy storage battery module in the case where the three-phase energy storage battery module of the energy storage unit is in an operating state comprises: Under the condition that three-phase energy storage battery modules of the energy storage unit are in an operating state, acquiring a plurality of SOCs (state of charge) of a plurality of energy storage batteries of each phase of energy storage battery module, wherein each SOC corresponds to one energy storage battery; and determining a phase of SOC according to the plurality of SOCs of each phase of energy storage battery module respectively to obtain the three-phase SOCs.
8. The energy storage unit SOC equalization control method according to any one of claims 1 to 7, further comprising: And controlling the energy storage unit to switch to a hot standby state under the condition that the inter-phase SOC difference value is smaller than the preset threshold value.
9. The utility model provides an energy storage unit SOC balanced control device which characterized in that includes: The difference value determining module is used for determining the inter-phase SOC difference value of the three-phase energy storage battery module under the condition that the three-phase energy storage battery module of the energy storage unit is in an operating state; And the charging control module is used for controlling the first phase energy storage battery module corresponding to the target inter-phase SOC difference to charge the second phase energy storage battery module corresponding to the target inter-phase SOC difference under the condition that the target inter-phase SOC difference is greater than or equal to a preset threshold value until the target inter-phase SOC difference is smaller than the preset threshold value, wherein the target inter-phase SOC difference comprises at least one SOC difference in the inter-phase SOC differences.
10. 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 energy storage unit SOC balancing control method of any of claims 1-8.
11. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a program code, which is callable by a processor to perform the energy storage unit SOC balancing control method according to any one of claims 1 to 8.

Description

Energy storage unit SOC balance control method and device, energy storage system and medium thereof Technical Field The application belongs to the technical field of energy storage, and particularly relates to an energy storage unit SOC balance control method and device, an energy storage system and medium. Background After the energy storage unit is operated for a period of time, imbalance is likely to occur in the three-phase State of Charge (SOC) of the three-phase energy storage battery module of the energy storage unit due to various reasons. At present, under the unbalanced three-phase SOC condition of the three-phase energy storage battery module, the problem of overcharge or overdischarge of the three-phase energy storage battery module easily occurs, and the service life of the energy storage unit is shortened. Therefore, SOC equalization control of the energy storage unit is needed. Disclosure of Invention In view of the above, the embodiments of the present application provide a method and apparatus for controlling SOC balance of an energy storage unit, an energy storage system, and a medium, 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 SOC equalization of an energy storage unit, including: under the condition that the three-phase energy storage battery module of the energy storage unit is in an operating state, determining the inter-phase SOC difference value of the three-phase energy storage battery module; And under the condition that the target inter-phase SOC difference value is larger than or equal to a preset threshold value, controlling the first phase energy storage battery module corresponding to the target inter-phase SOC difference value to charge the second phase energy storage battery module corresponding to the target inter-phase SOC difference value until the target inter-phase SOC difference value is smaller than the preset threshold value, wherein the target inter-phase SOC difference value comprises at least one of the inter-phase SOC difference values. According to the scheme provided by the application, under the condition that the inter-phase SOC difference value of the three-phase energy storage battery modules of the energy storage unit is large, the first-phase energy storage battery module corresponding to the large inter-phase SOC difference value is controlled to charge the second-phase energy storage battery module until the three-phase SOCs of the three-phase energy storage battery modules reach balance, so that the problem that the three-phase energy storage battery modules are overcharged or overdischarged can be reduced, and the service life of the energy storage unit is prolonged. In some optional embodiments, before the first phase energy storage battery module corresponding to the target inter-phase SOC difference value is controlled to charge the second phase energy storage battery module corresponding to the target inter-phase SOC difference value, the method for controlling SOC balance of the energy storage unit further includes: the energy storage unit is controlled to be disconnected from the electric connection with the power grid; Controlling the first phase energy storage battery module corresponding to the target interphase SOC difference to charge the second phase energy storage battery module corresponding to the target interphase SOC difference, comprising: under the condition that the energy storage unit is controlled to be disconnected from the electric connection with the power grid, the first phase energy storage battery module is controlled to charge the second phase energy storage battery module. According to the scheme provided by the embodiment, under the condition that the energy storage unit is controlled to be disconnected from the electric connection of the power grid, the SOC of the three-phase energy storage battery module is subjected to balanced control, so that the interference of the balanced control process on the power grid can be reduced, and the running stability of the power grid can be improved. In some optional embodiments, a load switch is disposed between the first phase energy storage battery module and the second phase energy storage battery module, and before the first phase energy storage battery module is controlled to charge the second phase energy storage battery module, the method for controlling SOC balance of the energy storage unit further includes: The load switch is controlled to be switched from an open state to a closed state; controlling the first phase energy storage battery module to charge the second phase energy storage battery module includes: and under the condition that the load switch is in a closed state, controlling the first phase energy storage battery module to charge the second phase energy storage battery module. According to the scheme provided by the embodiment, under the condition that t