| 摘要 |
PROBLEM TO BE SOLVED: To disconnect a distributed power supply surely when power supply from a commercial power supply is interrupted under a state where a commercial power supply and a distributed power supply are supplying power to a load by being linked mutually. SOLUTION: A signal of specific frequency is superposed by providing a signal superposition means 2 on the power supply side of a commercial power supply system. A system linkage protective unit 8 comprises means 8a for receiving the signal of specific frequency and a control means 8b. When the receiving means receives the signal of specific frequency, a switch 7 is closed through the control means 8b to connect a distributed power supply 6 and when the receiving means does not receive the signal of specific frequency, the distributed power supply 6 is disconnected. |
