A novel instrument for power quality monitoring based in higher-order statistics: a dynamic triggering index for the smart grid

Abstract

This paper presents a novel virtual instrument for PQ assessment, based in higher-order statistics. It implements a new power-quality index, which is thought to trigger the measurement procedure when an electrical fault comes about. The user interfaces include not only the online variance charts but also the skewness and kurtosis graphs, along with hybrid representations of variance versus higher-order statistics. Designed on the basis of 85 signals recorded, 50 Hz real-time with different disturbances. The instrument validates the PQ procedure during online sessions. The new monitoring strategy activates the analysis of the signal once the PQ index overpassed a predefined threshold. Results show that voltage sags and transients are classified within different clusters, with low uncertainty, using different types of graphs. This flexibility may allow the operator to reduce the subjectivities during the online monitoring session with an optimal computational solution.