Aiming at the problem of power quality which is easy to appear in the microgrid

the paper puts forward a suitable control method for the energy storage system of the microgrid to guarantee the power quality.It is proposed to adopt two kinds of storage battery equipment in microgrid

energy storage zinc bromine flow battery and power storage lithium titanate battery. The hybrid energy storage system adopts micro-grid DC/DC converter and DC/AC converter two-stage control

and the hybrid energy storage DC/DC converter control adopts a distribution method based on the nature of power fluctuations and constant current fast charge control

and the hybrid energy storage DC/AC converter adopts PQ control and an improved droop uniform frequency control method. The algorithm automatically switches in all kinds of operation mode of the microgrid to achieve the power quality indicators

such as voltage sag

frequency deviation

voltage deviation

and voltage fluctuation during the operation of the microgrid to meet the operating requirements. This paper also builds an overall simulation control model for an actual microgrid

and verifies that the main electric energy index of the microgrid is much higher than the national standard through the simulation of a typical example