RMS and power measurement using the dual-tree complex wavelet transform

Measurement of signal’s effective values and calculation of active-reactive-apparent-distortion powers using these measured effective values are one of the most important tasks in the energy systems. Calculations of the effective values and powers by using the classical methods are based on the Fourier transformations. On the other hand, due to the Fourier transformation having some disadvantages such as it’s being used in constant windowing functions and complex mathematical operations; it causes some undesired cases in the analysis of abrupt changed dynamic signals. Whereas, they are some alternative approaches based on the discrete wavelet transform and discrete wavelet packet transform. However, in the case of using the real wavelets, some problems occur such as oscillations, shift variance and aliasing. In this work, dual-tree complex wavelet transform has been used to calculate the effective values of the current, voltage signals and the power parameters. It has been observed that the carried out simulation and experiment’s results and the real values are consistent. Also, it has been shown in the simulations that the method is almost unaffected from the signal shifting.