Wavelet Packet Transform Based Parameter for the Analysis of Short Duration Power Quality Disturbances

The nature of today’s power system has become highly dynamic due to the increased use of nonlinear loads, power electronics based equipment and changed power system regulations. Conventionally, the Fourier transform (FT) is used for the power quality (PQ) analysis with parameters such as; THD and TDD. These parameters are suitable for stationary disturbances only. The recent state of power system demands to analyze the PQ disturbances on the basis of magnitude, time and frequency. In this paper, a new parameter based on Wavelet Packet Transform (WPT) is defined and tested for the short duration PQ disturbances such as; voltage sag, voltage swell, momentary interruptions, oscillatory transients and harmonics, simulated as per their broad definitions provided by the IEEE 1159-2009 standards.