Novel Compression Scheme of Fault Recording Data in Power Systems Based on Lifting Algorithm
YUE Quan-ming, YU Wei-yung, BAI Chuan-jun, FEI Ming-wei, DU Jun-hong ( Shanghai Jiaotong University, Shanghai 200240, China) (NARI-Relays Electric Co Ltd, Nanjing 211100, China) (Lin'an Power Supply Bureau, Lin'an 311300, China)
A novel scheme based on wavelet transform and its reversible transform of fault recording data compression in power systems by adopting lifting algorithm is presented in this paper. The computing formula to determine optimal decomposition layers'is derived for the first time from the point of view of sampling rate. The relationship between compression ratio and sampling rate is further expounded. All the parameters can be optimized in the course of determining general threshold values when the error upper limit is given. The applicability of the soft-threshold and the hard-threshold method has also been compared. Practical example result demonstrates that the computing time of the lifting scheme is nearly the half of that of Mallat algorithm, when applying them to the data compression by using the same wavelet transform. The higher compression ratio is obtained if adopting the proposed formula of the optimal decomposition layers, optimized parameters and the hard threshold method. In addition, the errors of compression can be controlled within a reasonable range.
【CateGory Index】： TM711