A. A. Khodadoost Arani - Electrical Engineering Department, Amirkabir University of Technology, Tehran, Iran
G. B. Gharehpetian - Electrical Engineering Department, Amirkabir University of Technology, Tehran, Iran
B. Zaker - Electrical Engineering Department, Amirkabir University of Technology, Tehran, Iran

Recently, with increasing penetration of distributed generations (DGs) in electricity networks, Microgrids (MGs) have been created. These MGs can operate in grid connected or islanded mode. Islanded operation of a MG has its own challenging issues. The main issue in off-grid operation is voltage and frequency control of MG. Energy storage system (ESS) can play an effective role in this situation. In this paper, battery energy storage system (BESS) is used to improve the control of voltage and frequency in off-grid mode. An appropriate control strategy for BESS is defined and used in order to regulate the voltage and frequency of an islanded MG. To show the effectiveness and accuracy of the proposed method, the proposed strategy is applied to CIGRE benchmark MG in MATLAB/Simulink. Different events such as islanding and load switching for static load and dynamic load (induction motor) are investigated with and without BESS and its control strategy

Battery energy storage system, Distributed generation, Islanded microgrid, Voltage and frequency control