Review on modeling and control of megawatt liquid flow energy storage system

Abstract

Flow battery has recently drawn great attention due to its unique characteristics, such as safety, long life cycle, independent energy capacity and power output. It is especially suitable for large-scale storage system and has a good application prospect. In this paper, the overall structure of the megawatt-level flow battery energy storage system is introduced, and the topology structure of the bidirectional DC converter and the energy storage converter is analyzed. Secondly, the influence of single battery on energy storage system is analyzed, and a simulation model of flow battery energy storage system suitable for large power grid simulation is summarized. The model of the whole system of flow battery is summarized from the grid-connected side and the energy storage system itself. The model of flow battery energy storage system should not only accurately reflect the operation characteristics of flow battery itself, but also meet the simulation requirements of large power grid in terms of simulation accuracy and speed. Finally, the control technology of the flow battery energy storage system is discussed and analyzed. The multi-DC/DC control strategy on the DC side and the parallel operation control strategy of the energy storage converter on the AC side are compared and analyzed. The advantages and disadvantages of each control method are analyzed accurately, which can provide reference for the modeling and control strategy of the megawatt flow battery energy storage system.