Electric Arc Furnace Power Quality Analysis Based on a Stochastic Arc Model

Electric arc furnaces (EAF) are commonly used in steel industry. Unfortunately, nonlinear characteristic of the arc furnace and its stochastic behavior bring about many problems, e.g. voltage flicker and waveform distortions. The AC furnaces are usually modelled using combined models which divide the phenomenon taking place in real objects into a deterministic and a stochastic or chaotic parts. The former can be expressed by a nonlinear differential equations. The paper goal was to take advantage of the earlier results, i.e. a closed form of the solution to one of the most popular nonlinear differential equations used for the AC electric arc modelling, and start research towards a complete EAC model which covers not only the deterministic but also the time-varying nature of the arc waveforms. Such a model can be helpful, among others, in solution to power quality problems in EAF supplying networks. Theoretical considerations have been illustrated by some examples and the results have been compared with measurements.