An Improved Time-domain Fault-location Algorithm for HVDC Transmission Line

Considering the frequency-dependent characteristics of HVDC transmission line, the error of calculated voltage distribution along the line is analyzed. Based on this, a voltage distribution calculation method using mixed line parameters is developed. Then, given that the voltage distributions of non-fault points calculated at both terminals have the largest difference around the fault time, the maximum voltage difference zone of non-fault points is defined to solve the problem that the difference of voltage distribution along the line change with the fault transient process. Thus, an improved time-domain fault-location algorithm is proposed. Finally, a PSCAD/EMTDC simulation model of one real HVDC project was constructed and extensive simulation results have verified the correctness of the proposed algorithm.