Experimental Investigation of Power Systems Arcing Faults Electromagnetic Source Characteristics
Conventional power systems protection functions mainly deal with over- currents and voltages associated with faults and most protection devices use relays and circuit breakers to monitor current, voltage, or impedance of critical setting values. However, in many arc fault conditions of earlier stage, the arc associated current amount is under the setting of relays, and subsequently the arc continues to burn with devastating effects which may put the entire system under risk. It has been observed that the power arc generates electromagnetic signals. It has been further observed that radiation producing power arcs can originate from different sources and causes: for instance, tree leaned on energized conductors or degradation of insulation materials. Since the advent of radar technology and antenna development, radio frequency (RF) emission sources can easily be detected. However, such radiation-based techniques have been attempted in power systems mainly for detecting partial discharge for insulation condition monitoring and lightning detection. Recently, a few approaches have been developed to detect power arcing faults employing radiation detection techniques; however, they are limited to the detection of radiation sources not their locations. This paper first attempts to investigate the characteristics of the electromagnetic signals radiated from the arcing faults and, second, validate the developed algorithms using laboratory produced arcs and strategically placed antennas which capture the radiation from the arcs. The advantage of the electromagnetic radiation-based detection and location of an earlier stage of arc is enormous in preventing and minimizing power interruptions and outages. By employing wireless sensors or antennas at a remote location for a laboratory staged arcs, this paper describes an experimental investigation for detection of different types of power arcs as they are mainly reported onsite. The characteristics of power arcing EM signals are analyzed and, from the characterization, their detection and location methods are proposed. In addition, practical implementation of the proposed methods for a real time monitoring system is discussed.