New Approach to Assess Unbalance and Harmonic Distortion in Power Systems

Abstract

This paper presents a new decomposition of the apparent power for power systems in unbalance conditions and harmonic distortion at Std. 1459 framework. From the new terms of power defined, a set of appropriate indicators to assess the unbalance in terms of harmonic distortion are introduced. From here, we obtain the balanced and unbalanced components for each set of voltage and current harmonics. The process is carried out through the application of the FFT to the Park vectors of voltage and current. This allows to develop an efficient algorithm from the computational point of view.. The algorithm has been implemented in a virtual instrument for measurements of a practical case. The results obtained show the utility of the proposed approach to assess the unbalance in the presence of distortion.