一种基于Hilbert和Chirp—Z变换闪变测量的改进方法

为了对电压闪变，提出了一种基于Hilbert和Chirp—Z变换的改进算法。首先介绍了Hilbert变换和Chirp—Z变换的原理，并从理论上推导了用Hilbert变换提取闪变包络线的公式。然后指出波动分量为方波时不能直接应用频谱分析法，需要对基于Hilbert和Chirp—Z变换的测量方法进行改进。最后用算例对所提方法进行仿真验证，证明该方法的正确性。

An Improved Method of Flicker Measurement Based on Hilbert Transform and the Chirp-Z Transform

In order to make an accurate measurement for flicker,especially when the wave vector is a square wave signal generated by voltage flicker,an improved algorithm based on Hilbert transform and Chirp-Z transform has been proposed.Firstly,the theory of the Hilbert transform and the Chirp-Z transform is introduced.The formula of extracting the flicker envelope by the Hilbert transform has been derived from the theory.In particular,by conveniently applying existing detection methods,larger error of the short-term flicker have been found when the wave vector was a square wave signal.According to this problem,an improved method was proposed.Finally,the correctness of the proposed method is verified by an example.