Photovoltaic power generation and urban power grid parallel power supply switching device

The invention relates to a photovoltaic power generation and urban power grid parallel power supply switching device which solves the problems of the existing device that the existing device is complex in structure, high in cost and poor in backflow-prevention performance during parallel power supply and a photovoltaic power supply cannot output the maximum power constantly. The photovoltaic power generation and urban power grid parallel power supply switching device comprises an alternating-current switching unit, a power supply unit, a control unit, a driving circuit, a sampling regulation unit and the like. The alternating-current switching unit is subjected to logic switching control by aid of the pulse width modulation strategy and the digital signal processor (DSP) software phase lock technology. The photovoltaic power generation and urban power grid parallel power supply switching device provides good guarantee for achievement of backflow-free photovoltaic power generation and urban power grid parallel