The detection and location of power quality disturbances based on orthogonal wavelet packet transform

A novel method of power quality detection and location using orthogonal wavelet packet transform was proposed. First the theories of orthogonal wavelet packet transform and wavelet basis function choice were discussed; second power quality disturbances with white Gaussian noise in power frequency were simulated; then, a soft-threshold method based on the concept of universal threshold and Stein unbiased risk threshold was given for solving the problem of de-noising in actual signal detection; finally power quality disturbances were detected and localized using orthogonal wavelet packet transform. The results show that the method proposed has a better detection performance; it has more accurate detection and location of the occurrence time and duration of transient. The method is suitable for detection of the transient and processing other non-time- varying signal.