A directional protection technique for MTDC networks

This paper suggests a new protection algorithm for a multi-terminal direct current (MTDC) networks. The current values and directions at each bus connecting more than one line are determined. The measured values of line currents are used to detect faulty conditions based on a specific threshold value. The faulted line is identified using the current direction through each line during a fault. For lines linking buses that connect multiple lines, simple communication system is required between the ends of these lines to identify an internal fault. The communication time is compensated due to the fast decision. Communication between buses is not required during normal conditions; therefore, the communication task is simplified. Simulation results show that the proposed algorithm is effective in protection of MTDC.