Probability approach for harmonic analysis of multi-converter system

In this paper, the sum harmonic currents of a multi-converters power system are analyzed by means of probability because of its random feature. A series of formulae to calculate the five important parameters of the normal distribution are presented, provided that the firing angle of each converter follows mean distribution. The study found that the random property of the sum harmonics becomes more evident as the number of converters, the harmonic order increases and the distribution range of the firing angle widens.