A novel algorithm of wide area backup protection based on fault component comparison

This paper proposes a novel wide area back-up protection algorithm that measures synchronized information from different buses in region. The amplitude of voltage fault component from different buses is compared, and the bus with maximum magnitude will be selected. Hence, suspected fault line set could be established according to the sub-graph and complete incidence matrix of selected buses. Then, voltage fault component amplitude at two sides of each suspected line could be calculated from another side, and the amplitude comparison between computed and measured value could be implemented. The ratio would be 1 when external fault occurs, and it would be greater than 1 when internal fault occurs. Thus, the fault line could be identified finally. The technique doesn´t need high precision synchronization of wide area information, and could response to different faults. The simulation of 10-unit and 39-bus New England system using PSCAD/EMTDC illustrates the effectiveness of this method.