Identification of fault and section identification in multi-terminal HVDC system using unit protection scheme

The Multi-Terminal Direct Current Transmission System (MTDC) is technically superior and economically more efficient than the AC transmission system, with a higher number of terminals providing access to remote power. The protection of MTDC transmission lines is essential for a smooth and reliable power supply. However, very few MTDC are operational today because of cost, control, and protection problems, especially because DC power lines are more susceptible to damage than AC lines. In this paper, we use one relay with single-ended data from the rectifier end to detect possible faults in the power line in the minimum amount of time. The proposed method is efficient as it can identify the faulty section and faulty pole with 100% accuracy. The reach setting of the proposed method is up to 100% of the line length.