| 摘要 |
PROBLEM TO BE SOLVED: To detect a different phase power supply mixture contact accident with high speed without unnecessary operation due to voltage drop or voltage loss such as a short circuit/ground fault accident occurring out of the protective section of a high order power supply side or a low order load side of an AC feeding circuit. SOLUTION: The different phase power supply mixture contact detecting relay device takes a sample analog wave form of a plurality of input voltage and input current at a constant period and converts it to a digital value, obtains respective voltage between four sets of different phase power supply from the time series sampling data of a plurality of input voltage, obtains respective bus current value of the different power supply from the time-series sampling data of a plurality of input current, determines the mixture contact accident from the comparison result with a determination value, and carries out a protective shut-off of the AC feeding circuit, when the mixture contact accident is detected. COPYRIGHT: (C)2007,JPO&INPIT
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