GROUND DETECTING DEVICE FOR PHOTOVOLTAIC POWER GENERATION SYSTEM AND METHOD

摘要

PROBLEM TO BE SOLVED: To exactly judge a ground state, by eliminating influence of an AC leakage current component of the electrostatic capacitance. SOLUTION: A differential current between the output line wires of a solar cell array 1 is detected by a current transformer 5, and the PMW component of an inverter is removed by a filter 10. Whether it is a ground state or not is judged by comparing the current which the 2fc component that is a frequency of two times of the system AC frequency is removed in a 2fc component removal circuit 15 with the required threshold value stored in a detection level setting device 21 by a comparator 20.