Evaluation of harmonic levels in electrical networks by statistical indexes

The problem of harmonic pollution in electrical networks is dealt with using statistical procedures. Due to the randomness of the operating conditions of nonlinear devices, a stochastic approach seems the most suitable for obtaining results meeting both technical and economical requirements. A comparative study is carried out on the effectiveness of semiempirical expressions which have been proposed to simplify the evaluation and forecasting of harmonic pollution levels in AC networks. It is found that the approximate model for the stochastic sum of harmonic currents at plant buses could be usefully employed for the design of network devices relevant to distortion and power factor compensation, such as filters and capacitors, as well as for the evaluation of immunity levels.<
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