Accidental contact between distribution lines of dissimilar voltages

Abstract

The accidental contact between 33kV and 11kV distribution lines is investigated. Experiments conducted on a contrived network showed that during a clash between high voltage and lower voltage conductors, the voltage on the high voltage side is pulled down to the low voltage value. The experimental results were emulated using electromagnetic transient modeling. The modeling was then extended to simulate clashes on a real network as a means of determining settings for protection relays to isolate the excessive fault currents and hence minimise the effects of such incidents.