Research on fault location scheme for inverter AC transmission line of AC–DC hybrid system

Abstract

As the nonlinear characteristics of converters, the harmonic components of fault information hardly decays with the passage of time, which introduces an estimation error in the fault location in the inverter AC transmission line of an AC–DC hybrid system, especially under commutation failure condition. Therefore, a new fault location scheme, which combines the dynamic synchrophasor measurement algorithm and line equivalent impedance/admittance estimation algorithm, is proposed in this paper. The precision of phasor estimation under harmonic environment has been improved. Based on these, the pre‐fault data of one circle is applied to estimate the line equivalent impedance and admittance. Finally, the traditional fault location formula based on the two‐end information is employed to calculate the fault location. Evaluation results show that the proposed scheme is independent of the fault resistance, fault distance, and fault type. More importantly, it ensures a higher precision of fault location in comparison with the dynamic fault location algorithm, even under commutation failure. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.