Energy storage battery charging and discharging method considering balance of battery pack of distributed energy storage system

Abstract

The invention provides an energy storage battery charging and discharging method considering the balance of a battery pack of a distributed energy storage system and a charging and discharging control system. The energy storage battery charging and discharging method comprises the following steps: collecting current and voltage data of each node of a distributed energy storage system, and calculating power needing to be absorbed/emitted by the energy storage system and SOC of each battery pack; according to the SOC of each battery pack, calculating the maximum power borne by the battery pack during balanced charging and discharging; after the BMS cuts off or accesses part of the battery packs, enabling the battery packs to realize balanced charging and discharging, wherein the designed control flow has a certain refresh frequency; and enabling the control flow to return to the first step to collect data again and circulate the operation. Balanced charging and discharging of the battery pack are spontaneously achieved according to the required power absorbed/emitted by the energy storage system, system shutdown operation is not needed, an additional balanced charging and discharging circuit is not relied on, energy can be fully utilized, and the system has the advantages of being simple in structure, easy to achieve, free of energy waste and capable of prolonging the service life of the battery pack.

Description

technical field [0001] The invention mainly relates to the technical field of distributed energy storage, and specifically relates to an energy storage battery charging and discharging method considering the balance of battery packs in a distributed energy storage system. Background technique [0002] Distributed new energy power generation is a hot spot in current research and engineering construction. In order to improve the new energy consumption rate and realize the smooth grid connection of new energy, distributed new energy power generation equipment is often equipped with energy storage systems. However, the battery stack formed by connecting a large number of battery cells in series and parallel is prone to unbalanced charging and discharging depth during the charging and discharging process, which reduces the cycle life and operating capacity of the battery energy storage system. Due to the high cost of battery energy storage systems, it is of great significance to ...

AI Technical Summary

Problems solved by technology

Aiming at the equalization management of lead-acid batteries and lithium-ion battery packs, there are currently patents disclosing a variety of active equalization methods, passive equalization methods, equalization circuit structures, equalization devices, and equalization control algorithms for energy storage batteries, but they are specifically for distributed energy storage systems. There are few patents, and the power characteristics and power fluctuations of distributed microgrids are not fully considered, so they cannot be fully applied to distributed microgrid systems.

At the same time, the number of batteries in a distributed energy storage system is often very large. If the balance of each battery cell is considered, it may cause compl...

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