| 摘要 |
<P>PROBLEM TO BE SOLVED: To constitute a synchronism detection relay capable of outputting a synchronizing signal even if the voltage conditions inputted from two power grids, which are objects, are different. <P>SOLUTION: An input side is provided with a tap for selection according to either an inter-line voltage condition or a phase voltage condition of the two power grids, at least either of which comprising a three-phase circuit. There are provided a pair of voltage input parts for converting to a voltage corresponding to a phase voltage and inputting it, a phase angle designation part which designates a phase angle between the voltages of the two power grids at a normal time, and a tolerable range storage part in which the tolerable ranges of voltage difference and phase difference are stored. A difference between the voltage values of the two power grids inputted from the voltage input part and a phase difference from the designated phase angle at a normal time are calculated. If the calculated voltage difference and the phase difference are within a tolerable range, a synchronizing signal is outputted. <P>COPYRIGHT: (C)2004,JPO |
