| 摘要 |
PURPOSE: A digital protective relay system is provided to be capable of making sampling timing the same among plural protective relay devices which operate independent from each other by using a signal from a GPS satellite. CONSTITUTION: A GPS(Global Positioning System) receiver(5a,5b) outputs a fixed cycle pulse(S0) at the same timing, received from a GPS satellite(4). On the other hand, clock signal generating sections(6a,6b) output clock signals(S1a,S1b), respectively. Timing difference measuring section(7a) measures the timing difference of the fixed cycle pulse(S0) and a sampling pulse(S2a). Sampling pulse(S2a) is output by sampling pulse generating section(9a). Similarly, a timing difference measuring section(7b) measures the timing difference of the fixed cycle pulse(S0) and a sampling pulse(S2b). Sampling pulse(S2b) is output by sampling pulse generating section(9b). A correcting sections(8a,8b) respectively correct the frequency of sampling pulse(S2a,S2b) so that the timing difference measured through timing difference measuring sections(7a,7b) is substantially zero.
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