New method for transient harmonics measurement based on wavelet transform

This paper presents a new time-varying harmonics measurement scheme based on the wavelet transform. By projecting the amplitude of harmonics onto the subspace spanned by the wavelet and scaling functions, the proposed method transforms the time-varying amplitude estimation into constant coefficient estimation, and achieves time-varying harmonics measurement using the least mean squares algorithm (LMS). Meanwhile, the recursive algorithm (RLS) realizes the online tracking for harmonics.