| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a short-circuit protector capable of protecting power transmission lines against short-circuit without requiring installation of an expensive transformer for gauge. Ž<P>SOLUTION: The short circuit protector 10 includes: a short circuit fault determining circuit 12 for detecting the presence or absence of a short-circuit fault in first and second power transmission lines 2<SB>1</SB>, 2<SB>2</SB>branched from a bus line 1 receiving a power supplied via R-, S-, and T-phase power cables 7<SB>R</SB>, 7<SB>S</SB>, 7<SB>T</SB>, based on each of short circuit currents I<SB>FR1</SB>, I<SB>FS1</SB>, I<SB>FT1</SB>and I<SB>FR2</SB>, I<SB>FS2</SB>, I<SB>FT2</SB>of each of phases which are input from current transformers 4<SB>1R</SB>, 4<SB>1S</SB>, 4<SB>1T</SB>and 4<SB>2R</SB>, 4<SB>2S</SB>, 4<SB>2T</SB>installed on each of the phases of the first and second power transmission lines 2<SB>1</SB>, 2<SB>2</SB>and R-, S-, and T-phase sheath currents I<SB>RS</SB>, I<SB>SS</SB>, I<SB>TS</SB>of the R-, S-, and T-phase power cables 7<SB>R</SB>, 7<SB>S</SB>, 7<SB>T</SB>; and a fault line identifying circuit 13 for identifying a fault line having the short circuit fault. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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