Detecting and Locating Corona Discharges in Low-Pressure Aircraft Environments Using Optical Sensors

Today, there is a clear trend toward electrification of transportation systems, including aircraft. Due to the enormous power requirements, they must operate at high voltages. However, the combined effect of higher voltage levels and low pressure environments is conducive to the occurrence of electrical discharges in electrical systems. Therefore, there is an urgent need to develop cost-effective systems to detect the discharges in the early stages before major failures can occur. This paper compares two optical sensors for early discharge detection in a simulated aircraft environment. The experimental study is performed in a low pressure chamber using a needle plane electrode. The pressure is changed from that corresponding to ground level to that corresponding to flight altitude, i.e., from 100 kPa to 20 kPa. The effect of the supply frequency is also studied, since modern aircraft operate in a wide range of frequencies up to about 800 Hz. Both variables, especially pressure, have shown significant effects on the CIV value. The results have also shown a similar sensitivity of both sensors for all the experimental conditions analysed, allowing a fast and sensitive detection and localization of incipient electrical discharge activity.