Identifying the root cause of power system disturbances based on waveform templates

Abstract

Most existing work related with power disturbance identification focuses on the classification of power disturbances, i.e. to identify the type of the power disturbances. It is however more important to know the root cause of the power disturbance when troubleshooting or responsibility assignment is required. For this purpose, a novel time-domain method is proposed in this paper for the root cause identification. The basic idea is to develop the waveform templates for describing each power disturbances of concern and then use the templates to fit the disturbances measured at the substation. Three common power system energization events including capacitor energization, no-load transformer energization, and motor starting, are investigated. All these events induce large currents to the system, thus are very likely to cause power quality issues. The effectiveness of the proposed method has been verified thoroughly using PSCAD/EMTDC simulations, lab experiment and field data.