Abstract:In view of an suppression of the resonance brought about by the integration of photovoltaic inverter clusters into the grid, a photovoltaic inverter cluster resonance suppression strategy has thus been proposed based on the active harmonic conductance method. Firstly, based on the double closed-loop control of inner capacitor current loop and outer grid current loop under PI controller, an analysis has been made of the resonance suppression effect of single inverter under double closed-loop control. Secondly, with the control system unchanged, active filter conductance is added to the photovoltaic grid connected system for a solution of the resonance problem of multiple inverters, which can not only effectively suppress the low-frequency harmonic current of inverter into the grid side system, but also improve the anti disturbance ability of inverter, thus suppressing the resonance problem caused by the inverter cluster. Finally, the simulation results of MATLAB / Simulink show that the cluster resonance of PV inverter can be effectively suppressed, and that the harmonic conductance method can effectively suppress the multiple inverter resonance.