A Two-Stage Control Strategy to Control the Energy Storage Source for Robust Performance of Microgrid Against the Loss of The Upstream Network or The Load Variation

this paper investigates a two-stage control strategy to control the energy storage source for robust performance of Microgrid against the loss of the upstream network or the load variation. The control strategy is designed in a way that in the first stage, the energy storage system keeps the balance between the load and the power and prevents the frequency and voltage to deviate. Then gradually it will decrease the battery output power to zero and simultaneously increase the power of the controllable distributed generation sources to keep the maximum capacity of the storage source available. In this paper, a low voltage microgrid constructed by the Korea Electric power industry research center is picked as a test case. This microgrid is connected to ۲۲.۹ kV grid through ۱۰۰ kVA transformer. It includes photovoltaic, the combined system of wind turbine and photovoltaic, two diesel generator, battery energy storage and three loads.