Reduction of voltage and current distortion in distribution systems with nonlinear loads using hybrid passive filters

Abstract

The widespread application of power electronics is increasing the number of electrical loads that distort the current and voltage waveforms in electrical distribution systems. Analysis of voltage and current harmonic distortion in a realistic distribution system was carried out. The dependence of the distortion levels on the interaction between load voltage and current harmonics, loading conditions, source impedance X/R ratio, and changing the load position, has been investigated. An iterative approach is implemented in order to study the effect of voltage and current harmonic interactions on the net system distortion. Calculation of the nonlinear load susceptances at different frequencies is presented. A hybrid reactance one-port compensator is designed to reduce the harmonic distortion in practical single-phase and balanced three-phase distribution systems having different types of nonlinear loads. The harmonic analysis is carried out in the time domain to accurately represent the system nonlinearity and voltage dependency.