Transient Positional protection of transmission lines using complex wavelets analysis

This paper presents a new high-speed protection scheme, transient positional protection (TPP), for power transmission lines. This scheme is developed using complex Wavelet analysis, based on the concept of transient-based protection (TBP), in which the fault-generated high-frequency transient signals contained in the primary voltages are utilized to detect fault position according to their relative travelling time and polarities. Combined information (CI) is obtained from complex wavelet coefficients to extract and localize a band of specified high-frequency components propagating along the transmission line. A typical 400-kV extremely high voltage (EHV) transmission system has been simulated by PSCAD/EMTDC to evaluate the scheme. The simulation results show that this scheme is capable of providing correct responses under various system configurations and fault conditions.