| 摘要 |
PROBLEM TO BE SOLVED: To easily detect a phase interruption or phase order without preliminarily retaining information based on magnitude relation of voltage value of each of three phases in normal power supply, and enable operation even with a wrong phase order. SOLUTION: This detector comprises an input voltage detection means 100, a three-phase/two-phase conversion means 101 converting input voltage on a statistic coordinate, an instantaneous angle arithmetic means 102 computing an instantaneous angle of input voltage, an instantaneous angle inclination arithmetic means 103, an average value arithmetic means 104 for inclination of instantaneous angle, an instantaneous angle sudden change detection means 105, an angle sudden change frequency detection means 106 detecting the frequency of instantaneous angle sudden change in a set period, and a phase interruption detection means 107 detecting phase interruption of AC power voltage based on outputs of the arithmetic means 104 and the detection means 106. COPYRIGHT: (C)2007,JPO&INPIT
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