Chaotic oscillator based protection scheme for single phase ground fault in distribution networks

Many distribution power systems have been operated with neutral ineffectively grounding to restrict the residual current for single-phase ground fault, so as to reduce outage and shock hazard. Earth fault current in the ineffectively earthed systems is usually not more than ten amperes. With general over-current relay, it is difficult to detect the earth fault and isolate the faulty feeder section. In order to improve it, a novel ground fault detection scheme based on chaotic oscillator is developed in this paper. The scheme has been verified by MATLAB simulation and tested in laboratory. Results show that the new protection scheme is able to detect faulty feeder and prevent electric shock with high sensitivity and robustness.