A comparative analysis of stability for battery energy storage system operating with diesel generator in a stand-alone microgrid

In this paper, stability of current control of battery energy storage system (BESS) connected with a diesel generator for a stand-alone microgrid are analyzed in four cases. The stand-alone microgrid system consists of 50kW BESS, 50kW diesel generator and controllable loads, where BESS is composed of 115kWh battery bank and 50kW DC-AC inverter. The four cases are 1) BESS with a stiff grid 2) BESS with the diesel generator 3) BESS with passive damping + diesel generator 4) BESS with active damping + diesel generator, and their stabilities are analyzed in the frequency domain and discrete time domain. Demonstration site for the stand-alone microgrid is constructed and comparative analysis for the four cases are verified through simulation and experiments, where experimental results show a good agreement with the analysis.