Classification of Composite Power Quality Disturbance Signals Based on HHT and S-Transform

The correct classification of single and composite power quality disturbances is the premise and basis of governance and control of power quality problems. This article extracts the high-frequency and low-frequency characteristics by S-transform of the disturbance signals, combining HHT to extract the instantaneous amplitude of the signal before and after the disturbance. Some characteristic functions is defined as the classification criterions by analyzing the characteristics of the disturbance signals, as to achieve the classification of power quality disturbances. Experimental results show that the fusion of the two methods can accurately detect the categories and characteristics of power quality disturbance signals, the starting and ending time of transient disturbance signals.