Power quality analysis based on a novel nonlinear dependence between parameters of nonsinusoidal regime

Abstract

Power quality analysis is one of the most important subjects of every power systems' interconnected parts. In fact, the nonsinusoidal regime represents the real operation mode of all the power systems, due mainly to distribution and consumers. Several parameters of power quality analysis are used by every national power system operator to impose specific standard limits and regulation which ensure optimal conditions of the electrical energy quality. Generally, all the limit values must be respected, even though they indirectly depend on one another. This paper proposes new relations between some parameters of power quality for the case of most common linear and inductive consumers, in order to unify the limits imposed on nonsinusoidal regime. Starting by the definition of relative values of voltage and current harmonics a new nonlinear dependence between the power factor and the total harmonic distortion of voltage and current is established. A quantitative approach of the nonlinear function has been assessed by using Matlab tools. The results are compared and discussed to the measured data for a large industrial consumer in two cases: with and without filters for power factor correction.