Hybrid Wavelet–Fourier Method for Harmonics and Harmonic Subgroups Measurement—Case Study

This paper deals with a problem of fast and reliable waveform disturbances recognition. It means real-time detection and evaluation of different kinds of waveform distortions such as harmonics, interharmonics, as well as transients and notching. In this paper, the problems of sampling frequency, a resulting number of samples and a complementary application of Fourier transform and a wavelet transform have been described. The main focus of this paper has been placed on harmonics and harmonic subgroups analysis. However, there is an assumption that harmonics are to be measured concurrently with transient and notching by a single dedicated device. All analyses have been carried out for the real voltages waveforms registered in ship and land electric power systems