A Study of Travelling Wave Fault Location
In the present modern era with the development of power systems, fast and accurate faults locations becoming more and more important. Power grids produce transient travelling wave signals, which transmit along the transmission line to each substation with the speed approaching the velocity of light. Using the exact arrival time of the fault traveling wave and the waveform characteristics recorded at each substation, the traveling wave based fault location and protection can be realized. The fault location has high precision, and the protection has fast action speed. So, current transformer saturation low frequency oscillation and fault resistance cannot influence it.
Fault location device (FLD) is installed at each substation in power grid, and travelling wave host computer is installed in control center. When a fault occurs, FLD records the switch operation information and the arrival time of the travelling wave, the information is then transmitted to the host computer. Lightning strike fault location method can only locate the fault caused by lightning, and it hardly satisfies the operation requirements in power system. Travelling wave fault location method with GPS is simple and with high precision, it has been applied in extra-high-voltage.