Self-adapted single-ended travelling wave fault location algorithm considering transfer characteristics of the secondary circuit

The transfer characteristics of a secondary circuit consisting of a current transformer) and a secondary cable are critical to the performance of single-ended travelling-wave-based fault locators. The non-ideal nature of the secondary cable often leads to distortion of the recorded travelling waves. In addition, this may lead to wave front identification failure. A high-frequency model of the secondary circuit is developed in this study. Based on the transfer function of the equivalent circuit, the distortion is found to be a superposition of two damped oscillation components. Recorded waveforms from an on-site device have been used to verify the model and analysis. A self-adapted single-ended fault location scheme is proposed to mitigate the influence of the damped oscillation components. The dyadic wavelet transform, pre-filtering Prony analysis and impedance fault location algorithm are used. The proposed method is tested on the recorded data, and precise fault location results are achieved. Different fault distances, fault impedances, secondary cable lengths and fault inception angles are also simulated to verify the proposed approach.