Optimum Shunt Capacitor for Power Factor Compensation in the Presence of Harmonics.(Dept.E)

Abstract

Power consumers require both reliable service and a acceptable voltage profile. The presence of nonlinear loads in power system generate harmonics which affect, in particular, the shape and magnitude of the supplied voltage, Classical design of capacitors for power factor compensation has been based on the undamental frequency analysis. However, the presence of harmonics and distortion, the compensated power factor is the short circuit generally worse. Additionally, according to capacity at the load bus, the calculated capacitor value could result in harmonic resonant conditions. A direct search technique known as Fibonacci Method (II) has been employed to determine the optimum capacitor bank size, and at the same time avoiding harmonic resonance in a power system with harmonic distortion. The method takes into account the effect of time variation of harmonic distortion, load level and short circuit impedance at load bus on the optimal solution. The proposed method has been illustrated through some actual cases of industrial loads existing in an Egyptian distribution network. The results highlighting the influence of harmonic distortion level, load level, and short circuit impedance have also been discussed in this paper.