| 摘要 |
PROBLEM TO BE SOLVED: To surely execute active detection of a single operation even in the case when distribute power sources are connected to a system in a parallel and multiple manner, by providing a single operation detecting relay which detects the single operation from fluctuation of the system synchronously with a disturbance generation timing signal and stops each distributed power source. SOLUTION: A disturbance generation timing circuit 17 supplies a disturbance generation timing signal T simultaneously at a prescribed period in synchronism with a disturbance generating part 16 of each inverter. Thereby each inverter 12 generates a disturbance of the same kind in its output simultaneously. A single operation detecting relay 18 detects the presence of a single operation from fluctuation of a system (fluctuation of frequency or voltage) synchronously with the timing of this generation of the disturbance. When the single operation is detected, the relay outputs a gate block signal S1 to each inverter 12 to stop the operation of the inverter 12 and supplies simultaneously an interruption signal S2 to a system interconnection switch 13 to cut off a distributed power source 10 from the system. |
