Investigation of multi-inverter distributed generation resident Sandia frequency shift anti-islanding method

With the popularity of the distributed generation (DG), grid-connected inverters are increasingly employed for the renewable energy sources utilization. The inverter is an interface between the power system and the micro-grid, and it is equipped with a variety of inverter control strategies and islanding detection scheme. Islanding detection function is an integrant function for grid-connected inverters. The current studies focus on single-inverter system, while the islanding detection strategies in multi-inverters operation are investigated in this paper. From the perspective of multi-inverter systems, this paper investigates the influence of the positive feedback anti-islanding on the stability. First, the analytical model of multi-inverter systems equipped with the positive feedback anti-islanding scheme is set up in the simulation environment of Matlab/Simulink. Second, the scheme´s impact on the multi-inverter systems is conducted to obtain the nature and characteristics, and the interactions among multi DGs caused by the scheme are presented in the paper. Third, based on the electromagnetic transient simulations, the above impacts and interactions are verified further. Finally, the conclusions are given out based on the analysis results.