Effect of Stray Capacitance in a Distribution Network on the Accuracy of Fault Location Based on Electromagnetic Time Reversal Method

The existing electromagnetic time reversal (EMTR) method for determining the location of faults in a distribution system does not consider stray capacitors in the system, leading to inaccurate fault location results. In this article, the influence of stray capacitors at the end and middle of the line on the EMTR method without considering the capacitance in the backward-time process was analyzed, the current signal energy of the fault location was derived, and the fault location was determined. A reduced-scale experimental platform of the EMTR method was built, and the influence of stray capacitors at observation points and middle of lines on the fault location results was verified. Finally, a fault location platform for a 33-node distribution network was built in power systems computer aided design (PSCAD) to explore the impact of stray capacitance on the fault location accuracy. The results showed that the error increases with the increase of the stray capacitance. This article found that considering the stray capacitance in the backward-time process can help determine the fault location more accurately. Besides, the signal observation point setting at low time constant area can also improve the accuracy when stray capacitance cannot be determined.