Wavelet-based Kalman Filter for Fundamental Component
Yongsheng Guo · Proceedings of the Chinese Society of Universities for Electric Power System and its Automation · 2012
In order to satisfy accurate action of relay protection,Kalman filter has been researched by domestic and foreign scholars in recent years.For that Kalman filter has response delay for fault,a novel method that wavelet transform and Kalman filter were mixed to extract the fundamental signal was proposed.The fault could be detected by using sym4 wavelet to transform and code the estimate value of fundamental signal.At the moment,the gain coefficient and the error covariance matrix would change so that the response time of Kalman filter is reduced.The simulation results demonstrate that the approach could exactly extract the fundamental signal of fault signal and detect the time of fault occurring.The approach can also exactly estimate the fundamental signal and was robust enough to system frequency variation within a certain range.