Selection and Application of Mother Wavelet in the Electric Power System Transient Protection
YANG Shu-ying1, WANG Li-hong1, DU Rong-hua1, SU Tao2(1.College of Electrical Engineering,North China Electric Power University,Baoding 071003,China;2.Shijiazhuang Honganzhongrui Electricity Equipment Co., Ltd.,Shijiazhuang 050021, China)
The identification, processing and utilization of power system transient signals are foundation of a new protection theory-transient protection.Wavelet transform has location-resolve ability in time and frequency domain.It is a powerful tool in processing the electric power system transient signals. The wavelet analysis theory and the characteritic of mother wavelets are discussed.The basis of selecting mother wavelet in analysis of transient signals common in power system is provided.Simulation is done on fault location of single-phase grounding fault and maloperation on reclosure of switchgear in a 500 kV transmission line. Simulation results are analysed by using the modulus of wavelet transform and multi-resolution-analysis,which proved the proposed method.