Traveling waves based protection relaying of power lines

With high speed data sampling technology development, fault generated high-frequency signals can be got, in which fault generated traveling waves reflects fault location, fault type and faulted equipment so on from different ways of traditional power-frequency information. Fault generated traveling waves may help to improve protection relaying. The paper will review fault generated traveling waves and its physical base at first. Then two cases will be presented to exemplify the advantage of traveling waves based protection relaying. One is that fault generated traveling waves with the speed of light can be used to protect UHV long transmission lines independent of capacitive charging current. The other is traveling wave will be applied to detect single-phase-to-ground fault in power distribution system with neutral non-effectively grounded. At last the paper will conclude with implementation of traveling wave based protection relaying.