Photovoltaic power generation system

A solar cell array having an exposed electroactive portion is connected to a system power supply through an insulation transformer, a ground-fault interrupter is provided between the solar cell array and the system power supply, and a ground-fault detector is provided at the grounded line of the solar cell array. A set current value at which the ground-fault detector judges a ground-fault is larger than an amount of a set current value at which the ground-fault interrupter interrupts a circuit. The insulation transformer is provided between the solar cell array and the system power supply. Owing to such structure, the present invention aims at the simplification of environment-resistive coating having a large ratio of cost of the solar cell, and the simplification of insulating coating of members that connect the solar cells in series and parallel, and provides a photovoltaic power generation system which does not stop by the leakage current of the electroactive portion in connection with such simplification of the environment-resistive coating and insulating coating.