DIGITAL-SIMULATION OF FAULT LOCATION ON EHV LINES USING WIDE-BAND SPREAD-SPECTRUM TECHNIQUES

Spread spectrum techniques perform well in high-noise environments suc h as power lines, and their use in radar ranging is well known. Existi ng power line carrier (PLC) equipment may be used to transmit a direct sequence signal down a faulted EHV line. The fault position may then be calculated from correlation analysis of the reflected waveforms. Th is fault-location process has been simulated on a digital computer by taking into account the frequency variation of the PLC interface and l ine parameters over the spread spectrum bandwidth. The effect of wavef orm characteristics and fault location are examined for a 100 km doubl e transposed line with a single phase to ground fault. Results indicat e that permanent faults may be located to within 0.5 km.