| 摘要 |
PROBLEM TO BE SOLVED: To provide a ground fault detection device capable of detecting a ground fault current in a DC source circuit with high sensitivity. SOLUTION: In the ground fault detection device 1, a control circuit 11 measures an inter-ground voltage V<SB>P</SB>at a P side of a DC source E and an inter-ground voltage V<SB>N</SB>at an N side thereof and calculates an unbalance ratioαwhich a ratio of the inter-ground voltage V<SB>P</SB>at the P side to the inter-ground voltage V<SB>N</SB>at the N side. The control circuit determines whether or not the calculated unbalance ratioαexceeds a predetermined threshold T. When it is determined that the unbalance ratioαexceeds the predetermined threshold T, the control circuit determines that the ground fault current flows in the DC current circuit 10 so as to detect the ground fault. COPYRIGHT: (C)2011,JPO&INPIT
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