Multi-resolution analysis based data compression for power transformer protection

In this paper, a multi-resolution hybrid technique based data compression for protection of power transformer is presented. This hybrid technique is established by combining the d-q axis transformation with the wavelet packet transform (WPT) to provide the proposed (dqWPT) hybrid protection technique for power transformer. In this technique, signal decomposition and reconstruction are carried out for the collected fault and inrush current signals for different types of mother wavelets at a certain number of levels. The number of levels has to be kept the minimum for optimal use. Minimum description length (MDL) method is used to select the best mother wavelet, and the optimal number of decomposition levels required for the power transformer protection using the proposed technique. For this analysis, the Daubechies db4 is selected at one level of resolution is utilized to implement the proposed technique. The proposed technique has shown good results with the selected mother wavelet for different disturbances at the power transformer.