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.

Assessment of unbalance and distortion in power systems that include active power line conditioners.

“…On the other side, an independent measurement system [9] to calculate the indices is implemented in another data acquisition card (dSPACE-DS1005), with a signal conditioning system formed by six voltage sensors (LEM-LV25-P) and eight current sensors (LEM LA35-NP). These signals are taken simultaneously to avoid phase differences between the measurements, to enhance the accuracy of the calculated results.…”