Detection and Location of Arcing Faults in Distribution Networks Using a Non-Contact Approach

The task of accurately locating the origin of a fault on the distribution network is currently an arduous one, often requiring repair teams to engage in a time consuming search on foot or in vehicles. It cannot be solved by reusing the methods successfully applied to the location of faults on the electrical transmission network. Methods which require monitoring equipment to be physically connected to the distribution network are undesirable due to cost and the risks to personnel and supply associated with fitting and operating such equipment. A novel wide-area, non-contact approach is presented here. When a network fault induces an electrical arc it is accompanied by the radiation of electromagnetic transients which can be captured as a signal which radiates in the radio spectrum. By capturing these emissions at geographically separate locations it is possible to determine their common origin by using their time-difference-of-arrival at each monitoring location. A monitoring network comprising 4 stations was commissioned and installed at locations to the north-east of Glasgow, Scotland in order to monitor a section of the distribution network. Using this monitoring network it was demonstrated that it is possible to capture the radiometric emissions from fault-induced arcs and lightning strikes. The range for detecting network faults with the present system was found to be in the region of several km, but needs to be increased further to make this approach viable for fault location.