Liquid metal battery pack two-stage bidirectional equalization system and control method

Abstract

The invention discloses a liquid metal battery pack two-stage bidirectional equalization system and a control method. The liquid metal battery pack two-stage bidirectional equalization system comprises an upper computer, M first-stage equalization systems and a second-stage equalization system; one first-stage equalization system comprises N flyback conversion modules, a voltage acquisition module, a central control module and a 485 communication module; one second-stage equalization system comprises M double-half-bridge DCDC conversion modules, a central control module and a 485 communication module; and the upper computer controls a lower computer through a 485 bus. According to the liquid metal battery pack two-stage bidirectional equalization device and the control method provided by the invention, bidirectional electric quantity transfer between a battery pack and batteries and between the battery pack and a battery module can be realized, the electric quantity transfer efficiency is high, the speed is high, and the problem of inconsistent battery states after large-scale grouping of liquid metal batteries is well solved.

Description

technical field [0001] The invention belongs to the field of large-scale energy storage for power grids, and in particular relates to a two-stage bidirectional equalization system and a control method for a liquid metal battery. Background technique [0002] The shortcomings of new energy such as poor stability and geographical constraints limit its large-scale application, and energy storage technology, known as the "last mile" of new energy technology, can solve the instability of new energy grid connection and regional distribution differences. played a very important role in such issues. Among the new chemical energy storage batteries, liquid metal batteries meet the development needs of energy storage systems due to their advantages of high capacity, high current and low cost. [0003] The working temperature of the liquid metal battery is about 500°C, and the structure is composed of three liquid materials, among which two metals with different densities that are heat...

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Problems solved by technology

[0006] In order to overcome the shortcomings of low energy transfer efficiency, large energy loss and small group size of the existing liquid metal battery equalization system, this patent provides a two-stage two-way equalization control system, the two-stage equalization of the system can achieve a larger Balance the current, and realize the bidirectional transfer of energy, improve the energy transfer efficiency and reduce the equalization loss, and is suitable for large-scale group applications of liquid metal battery packs

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