A new starting capability assessment method for induction motors in an industrial islanded microgrid with diesel generators and energy storage systems

Induction motor (IM) startup can cause voltage dip disturbances and is detrimental to the stable operation of industrial islanded microgrids. Firstly, this study investigates the active power characteristics of the diesel generator and battery energy storage system (BESS) with IM based on the steady-state equivalent circuit to determine the starting capability of an islanded microgrid. Then, the starting conditions and the stable feasible region of the diesel generator and BESS with IM are further deduced considering different mechanical power models. A new Starting Capability Index (SCI) for the IM of the islanded microgrid with diesel generators and BESS is proposed to assess the microgrid's overall starting capability and arrange the starting sequence during motor startup in different locations of islanded microgrids. Based on SCI, a strategy to determine the starting sequence of multiple IMs in the islanded microgrid is proposed to improve the quantities of IM startups and the microgrid's dynamic performance. Two cases of an islanded microgrid with diesel generators and BESS are tested using MATLAB/ SIMULINK to verify the effectiveness of the proposed methods.