Arc furnace current and voltage harmonics analysis using the wavelet packet transform

This paper studies the application of Wavelet Packet Transform in identifying harmonics in both the voltage and current waveforms of AC electrical arc furnaces. It takes into account the special behavior of this type of devices in terms of load that leads to voltage and current fluctuations, which usually are a source of interharmonics. Possible inaccuracy in harmonics identifying process in applying IEC criterion using the FFT is studied and the results are compared with those obtained by applying the wavelet transform. The study was conducted on both simulated signals and voltage and current waveforms in the meltdown arc furnace of a steel mill.