LOCALIZED APPLICATION OF HIGH IMPEDANCE FAULT ISOLATION IN MULTI-TAP ELECTRICAL POWER DISTRIBUTION SYSTEM

摘要

A high impedance fault isolation system (HIFIS) identifies, isolates and dissipates high impedance, low current faults which occur within an individual tap, or branch, of an electric power distribution system using only portions of the tap affected. A master meter, or father smart meter (FSM), on the affected tap sends a coded signal to an antenna receiver combined with a microprocessor and chip (420) which operates an electromagnetic control (EMC) grounding spring (409) switch which isolates the downed primary conductor by causing the distribution system protecting device (334), i.e., a high voltage fuse or recloser, to de-energize the downed primary wire. This localized application of the HIFIS at the individual tap level allows the FSM to analyze and determine, for example, that the specific field condition is a "downstream wire down", and that the installed isolating device has failed to operate because of insufficient fault current, allowing the localized intervention of the HIFIS to achieve the de-energization more efficiently and safely, and within a much shorter time period. A fire door sensor circuit then receives the trip signal from the microprocessor, causing the fire door sensor to melt open and release a shorting spring, in initiating operation of an expulsion fuse or recloser, which kills the downed live wire.;Fig. 3