Photovoltaic grid-connected converter, photovoltaic power supply system and electric appliance

The invention discloses a photovoltaic grid-connected converter, a photovoltaic power supply system and an electric appliance. The photovoltaic grid-connected converter comprises a boosting chopper, a by-pass switch and a conversion circuit, wherein the boosting chopper is connected with a photovoltaic array and used for performing boosting conversion on output voltage of the photovoltaic array, the by-pass switch is connected with the boosting chopper in parallel and used for bypassing the boosting chopper when the output voltage of the photovoltaic array exceeds a preset voltage threshold value, and the conversion circuit is connected with the output end of the boosting chopper and used for performing direct-current and alternating-current conversion on output currents of the boosting chopper. Through the photovoltaic grid-connected converter, the problem that in related technologies, the conversion efficiency of a photovoltaic grid-connected converter is low is solved.