| 摘要 |
PROBLEM TO BE SOLVED: To provide a protector and a protection method of distribution system in which arrangement of a load-break switch can be simplified. SOLUTION: When a decision is made that power flows into premises (forward power flow), a control section 35 excites a trip coil 25 to open a load-break switch 17. When a decision is made that power flows out from premises (reverse power flow), the control section 35 does not excite the trip coil 25 but sustains throw-in of the load-break switch 17. Consequently, unnecessary opening of the load-break switch 17 due to generation of an eddy current caused by short circuit failure on the outside of premises can be suppressed in a distribution line 11 linked with a distributed power supply 15 in the premises. Furthermore, an operating power supply voltage on the consumer load 14 side is employed as a reference voltage for judging power flow direction. Since power flow direction is judged based on the phase of a load current I<SB>R</SB>for a control power supply voltage Vp, an extra voltage sensor is not required in the load-break switch 17. COPYRIGHT: (C)2006,JPO&NCIPI
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