A novel single-ended fault location method for long-distance HVDC transmission lines based on cross-correlation analysis

Abstract

The transmission line, as the faultiest device in power system, cross many complex areas which will cause worse work condition. This is, both the rate of faulty and the difficulty of the manual fault location are raised. While accurate fault location method could reduce the workload and outage cost, increase the speed of repairing and improve both the reliability and economics of power system. Therefore, it is essential for HVDC systems which have much longer transmission lines. The existing fault location device of HVDC transmission lines are based on the principle of transient travelling-wave. However, due to the interference caused by on-off of power electronic devices and signal resonances, the single-ended travelling-wave method can not be applied in HVDC. The characteristics of clutter interferences of HVDC system and the coupling between double pole lines are analyzed in paper. A novel single-ended travelling-wave fault location method for HVDC transmission lines based on the correlation between two pole lines is proposed. The signal of the non-fault pole line is applied as reference signal; the method suppresses interference through the cross-correlation calculation between the fault and the no-fault pole line. So the reflected wave is enhanced and the identification reliability of the reflected wave is improved. The validity of the method is verified by simulation and on-site data analysis.