RF detection of electrical discharges in aerospace applications

Abstract? High voltage power electronic systems are increasingly being used in aerospace applications with a target of increasing the power density of such packages, minimizing weight and/or volume. The use of high voltages in an aerospace environment is creating additional challenges for the equipment supplier who must warrant that their equipment is free of electrical discharges (this term encompassing partial discharge, tracking and disruptive discharges. At present there are no clear standards that relate to how aerospace equipment should be shown to be free of electrical discharges. While individual components of a system can be tested using existing laboratory techniques, the test of the complete system is more challenging. Of increasing interest is the use of radio frequency (RF) techniques which rely on monitoring the electromagnetic emissions associated with the electrical discharges. This experimental work reports the applicability of RF techniques in detecting electrical tracking in systems working at sea level and/or at high altitude (pressures between 11.6-101.3 kPa). The measurements that have been carried out have been undertaken in a controlled electromagnetic noise-free environment with different antennas. Preliminary recommendations are made as to the applicability of RF measurements in detecting electrical discharges within aerospace power electronic systems.