A coordinated optimization method considering time-delay effect of islanded photovoltaic microgrid based on modified backtracking search algorithm

Photovoltaic (PV) microgrids operating in the islanding mode are more susceptible to stability problems, due to the fluctuation of PV output power and weak system structures. In this paper, a coordinated optimization method considering the time-delay effect of islanded PV microgrids based on the modified backtracking search algorithm is proposed to improve the stability of PV on the condition of suffering small disturbances. First, the small signal model of PV microgrid considering time-delay characteristics of the inverter, which consists of a PV array, batteries, dc/ac inverters, and loads, is studied. Then, the range of controller parameters are obtained by analysing small signal stability using the technique of eigenvalue analysis. Finally, a coordinated optimization objective function is built and the modified Backtracking search algorithm is adopted to optimize the parameters. The simulation results show that the proposed method is effective for improving the stability of PV microgrids when suffering small disturbance. Published by AIP Publishing.