Multi-level active equalization circuit of energy storage battery system and control method thereof

Abstract

The invention discloses a multi-level active equalization circuit of an energy storage battery system and a control method thereof. A battery energy storage system is divided into a plurality of modules by adopting a multi-level active equalization structure; wherein the active equalization circuit comprises an intra-group equalization circuit and an inter-group equalization circuit, the intra-group equalization circuit comprises a battery state information acquisition circuit, an intra-group switch array, an intra-group bidirectional DC-DC circuit and a slave MCU, and the inter-group equalization circuit comprises an inter-group switch array, an inter-group bidirectional DC-DC circuit and a master MCU; intra-module equalization is achieved through active equalization in the modules, and equalization between the modules is achieved through adoption of the module equalization main circuit. Effective utilization of energy in the energy storage battery system can be achieved, the overallcapacity and the power performance of the battery pack can be effectively improved, and meanwhile, the equalization time is shortened.

Description

technical field [0001] The invention relates to an energy storage battery system equalization control technology, in particular to a multi-level active equalization circuit and a control method for an energy storage battery system. Background technique [0002] With the continuous development of battery energy storage technology, a large number of large-scale energy storage power stations have been put into the operation of the national grid, playing an important role in power generation, transmission, distribution and power consumption. Due to the difference in the manufacturing process and the use environment of the battery during the manufacturing process, the battery power will be unbalanced after long-term use. The inconsistent power of the battery cells in the battery pack will lead to a reduction in the overall capacity of the battery pack. The electricity released is lower than the superposition of monomers. At the same time, due to the constraints of individual cel...

AI Technical Summary

Problems solved by technology

[0005] When the traditional equalization structure and control method performs equalization control, due to the large number of cells that make up the battery pack, it takes a lot of time to equalize the battery cells one by one, and the existing solutions are often aimed at the inside of the battery module, and the balance between modules lacks consideration. , and more importantly, there is a lack of overall control over the balance of the energy storage battery system. All of the above reasons will cause the problems of long equalization time and poor equalization effect

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