| 摘要 |
<P>PROBLEM TO BE SOLVED: To measure a total value Igr of leakage current which passes through a distribution wire where power is supplied from a 400 V class star distribution power source and a ground insulation resistance of a load facility connected to the distribution wire. Ž<P>SOLUTION: Signal processing is performed for any one of one-phase ground voltages of Er, Es, Et among three-phase ground voltages inputted from the star distribution power source 1 and a zero-phase current I<SB>0</SB>detected from the distribution wire 4 by a zero-phase transformer 9, and any one of the one-phase ground voltages Er, Es, Et is inputted. A signal processing part 14 performs signal processing by measuring the phase difference between the input voltage and zero-phase current I<SB>0</SB>. The phase angle of the zero-phase current I<SB>0</SB>obtained by the signal processing part 14 with respect to the input voltage is computed. With it and the value of the zero-phase current I<SB>0</SB>, an effective component A and a reactive component B with respect to the input voltage are computed. From these effective values, the total leakage current value Igr of each phase except one sound phase which passes through a ground leakage resistance 7 and its reliability are computed. The maximum value and the minimum value of the leakage current Igr computed by a computing part 15 and further the leakage current value Igr are displayed on a display part 16. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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