A proposal for the automatic evaluation of the mean curve required by the ANSI/IEEE Std 4-1978

The paper proposes a method, based on the wavelet packet transform, for the automatic evaluation of the mean curve required by the ANSI/IEEE Std 4-1978. After some theoretical remarks on the wavelet packet transform, the fundamental stages of the method are illustrated in detail. Results obtained with analytical impulses and real impulses digitized in some European high-voltage laboratories show the effectiveness and reliability of the method. Suggestions to improve the present standard are also given.