| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a protecting method of a power system, with which the power system can be operated with stable power demand-and-supply balance only by interrupting a minimum load even if power supply from a purchased power system stops when a part of private power-generating facilities is in a non-operation state due to repair or inspection. <P>SOLUTION: In the power system supplying power from the purchased power system and a plurality of private power-generating facilities 3a to 3c to a plurality of loads 4a to 4e through a transmission line 1, two or above frequency relays 5a to 5c are arranged on the transmission line 1. The frequency relays 5a to 5c interrupt the loads 4a to 4e by different frequencies of power. When drop of the frequency of power of the transmission line 1 is suppressed, it is maintained to a range which is previously set and the system is protected if power supply from the purchased power system stops, the loads 4a to 4e connected to the frequency relays 5a to 5c are previously changed based on a power generation amount of the private power-generating facilities 3a to 3c which are scheduled to be not operated and a total power amount of the purchased power system. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
