String type flow battery energy storage system

Abstract

The invention relates to a string type flow battery energy storage system which comprises a plurality of flow tanks, a plurality of electric pile containers, a plurality of direct current conversion devices, a converter and a transformer, each stack container comprises at least one series loop, each series loop is formed by connecting a plurality of single cell stacks in series, each single cell stack is connected with a liquid flow tank, the output end of each series loop is connected with a direct current conversion device, and the direct current conversion device is used for direct current boosting of the output voltage of the series loop. The output ends of the DC conversion devices are connected in parallel to the same current collection bus, the other end of the current collection bus is connected with the converter, the output end of the converter is connected with the transformer, and the other end of the transformer is connected to a power grid. The direct-current output voltage of the flow battery energy storage system is improved, the configuration number of boosting equipment, PCS, protection equipment and the like is greatly reduced, the arrangement structure of the energy storage system is simplified, the occupied area is reduced, the operation safety is improved, and the maintenance and input cost is reduced.

Description

technical field [0001] The invention relates to the technical field of energy storage, in particular to a string type liquid flow battery energy storage system. Background technique [0002] Flow batteries are commonly used in electrochemical energy storage systems, where charging and discharging are achieved through redox reactions between active ions contained in the positive electrolyte and active ions contained in the negative electrolyte. The output power of the flow battery is several thousand watts to tens of megawatts, and the energy storage capacity can reach more than several hours. It is one of the technical routes of large-scale energy storage and plays a very important role. [0003] In the current flow battery technology, the single-cell DC voltage of the battery stack is relatively low, and multi-stage boosting is required to achieve a higher output voltage, which requires more boosting devices. However, multi-stage booster equipment will lead to a decrease i...

AI Technical Summary

Problems solved by technology

The series flow battery energy storage technology can reduce the number of step-up stages and reduce the number of electric equipment, but the current DC output voltage level of the string flow battery energy storage system is low, and the maximum output DC voltage is 1000V , the power of the DC conversion device used is small, the number of installations needs to be large, the floor area is large, the scalability of the entire energy storage system is not good, and the operation, maintenance and input costs of large-scale energy storage systems are generally high

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