Leakage error analysis and algorithm improvement for wavelet Mallat harmonic measuring
Xuewei Wang · Dianli zidonghua shebei · 2009
Mallat algorithm is normally adopted in wavelet transform sub-band measuring of power harmonics.Its accuracy is higher under synchronous signal sampling conditions,while there is greater in-band leakage error under asynchronous signal sampling conditions,of which the expressions in frequency domain are derived.Simulation and experiment show that,the relative in-band leakage error may reach 5 × 10-2.To reduce the leakage error,an anti-overlapping filter is constructed with integer lapped windows and an anti-leakage algorithm is proposed.Simulation shows that,its relative error of RMS measurement is less than 1.3×10-4,and the experiment shows that,its fiducial error of power measurement is less than 1.3 ×10-3,1～2 grades better compared with conventional wavelet Mallat algorithm.