A photovoltaic power generation system includes a capacitor bridge arm, an inverter bridge arm, and the fault protection apparatus. The capacitor bridge arm includes a positive electrode output port, a negative electrode output port, and a reference output port The inverter bridge arm includes a positive electrode input port, a negative electrode input port, and a reference input port. The positive electrode input port is connected to the positive electrode output port. The negative electrode input port is connected to the negative electrode output port. The reference input port is connected to the reference output port by using the fault protection apparatus. The fault protection apparatus is turned off based on a magnitude value or a variation of a voltage, or a magnitude value or a variation of a current between the reference input port and the positive electrode input port or the negative electrode input port.