Integrated line and busbar protection scheme based on wavelet analysis of fault generated transient current signals

This paper presents a new directional relaying principle, which integrates the power line protection with the busbar protection together. In the presented technique, the relay installed at the busbar is responsible for the detection of fault direction with respect to the busbar. The transient signals captured from CTs related to the power lines connected to the busbar are processed with a wavelet technique to determine the fault direction. Simulation studies show that the scheme is insensitive to fault type, fault position, fault path resistance and fault inception angle. It has been shown the presented scheme is suitable for all types of faults occurring at different sections on the power lines or the busbar and its associated equipment. In addition, the technique is fast in response, simple in principle and easy to implement.