Protection method and device for photovoltaic power generation power system

The invention provides a protection method and device for a photovoltaic power generation power system, and relates to the technical field of electric power, the photovoltaic power generation power system comprises an inverter, an inverter connecting end, rectification control circuits and a circuit breaker, the rectification control circuits are arranged on any two phases of the inverter alternating current side and the inverter connecting end, and the circuit breaker is arranged on any two phases of the inverter connecting end. The circuit breakers are arranged on three phases of the connecting end of the inverter, and the method comprises the steps that when the inverter breaks down, the rectification control circuit is controlled to work; acquiring the current of the rectification control circuit; and the circuit breaker is controlled according to the current. Therefore, through the arrangement of the rectifying circuit, the connection between the inverter and the inverter connecting end can be disconnect