Comparative Analysis of Power Quality Instruments in Measuring Power under Distorted Conditions

Abstract

Abstract This paper aims to evaluate the performance of commercial power quality (PQ) instruments. By using a high precision programmable voltage and current source, five meters from different manufacturers are analyzed and compared. At first, three-phase voltage signals are applied to those PQ instruments, considering harmonic distortion, voltage dip, voltage swell, as well as unbalanced voltages. These events are measured, compared and evaluated considering the different instruments. In addition, voltage and current signals are applied under different conditions, with and without harmonic and unbalances, in order to obtain the measurements of electrical power. After analyzing the data generated in all these tests, efforts are focused on establishing a relationship between the accuracy of the measurements. Considering the percentages of errors, a score is assigned to each instrument. The tests have shown “excellent” and “good” results regarding measuring active and apparent power, as well as power factor. However, for non-active power, almost all instruments had lower performance. This work is relevant considering that Brazil is deploying standardization in terms of power quality measurements aiming towards regulatory procedures and index limits.