Method and apparatus for the ground fault protection of a solar power plant and solar current system, which is used, the process and apparatus

摘要

PROBLEM TO BE SOLVED: To prevent unnecessary stoppage of a sunlight power generation system by providing a means which outputs a gate block signal to a gate block means, and a break command signal to a mechanical breaking means to load, individually, when a ground fault occurs inside a solar cell array. ;SOLUTION: A detection means 1 and a first continuance confirmation means 2 output a gate block signal from a gate block signal production means 3 to a gate block means when they detect the ground fault occurring continuously for a first specified period. Then, when a ground fault is detected again in the detection means 1 and the second continuance confirmation means 4 after the passage of the second period longer than the first period, a break command signal is given to a mechanical breaking means from a break signal production means 5, judging that it is faulty. When the ground is not detected once again, the gate block signal is canceled. As a result, malfunctions decrease, and high reliability can be obtained even in a long time operation.;COPYRIGHT: (C)1999,JPO