Frequency conversion control of photovoltaic grid-connected inverter based on LCL filtering

Abstract Aiming at the problem that filtering effect of inductor capacitance (LCL) filter becomes worse when Photovoltaic (PV) system works low power, this paper presents a control strategy to change switching frequency according instantaneous output power inverter. By analyzing design method each parameter LCL filter, single-stage PV grid-connected inverter structure is used establish loop based on grid voltage-oriented vector determine optimal under current state. The methods detector, calculation and hysteresis comparator are analyzed in detail. Finally, waveforms before after conversion contrasted by MATLAB simulation verify feasibility effectiveness strategy.