Probabilistic representation of harmonic currents produced by AC/DC static power converters

This paper presents a method for analyzing the behaviour of the sum of randomly varying harmonic currents produced by static power converters. The method is applied in a typical stochastic harmonic problem where several converters are supplied by the same feeder and both the firing angles of the converters and the switching mode of each converter are allowed to vary randomly. To achieve a more realistic picture of the underlying problem, a deterministic approach is implemented first to analyze the system under different extreme conditions and to set the upper and lower limits of the level of each harmonic current component. Then, the overall probabilistic model of the power system is solved within the preset boundaries. Finally, the obtained results are presented and discussed.