Evaluation of noise reduction in experimental battery pack voltage using discrete wavelet transform and wavelet packet transform

This study deals with an interesting approach that clearly evaluates the noise reduction in noise-containing experimental discharging/charging voltage signal (DCVS) based on the discrete wavelet transform (DWT) and the wavelet packet transform (WPT). The key difference to be considered is the multi-resolution analysis (MRA)-based decomposition ability of high frequency band. By comparison with the DWT, it surely can be expected to have the binary tree structure that can decompose low and high frequency bands. As a result of an evaluation of noise reduction using the DWT and the WPT, it can be shown that the performance on noise reduction of the WPT is superior to that of the DWT. This approach considered an experimental battery pack of 2S3P in series/parallel connection using 2.2Ah LiCoO₂ unit cells.