Aircraft electric system intermittent arc fault detection and location

Abstract

Intermittent arc faults appear in aircraft power systems in unpredictable ways when the degraded wires are wet, vibrating against metal structures, or under mechanical stresses. They could evolve into serious faults that may cause onboard fires, power interruptions, system damage and catastrophic incidents, and thus have raised concern. Recent trends in solid state power controllers (SSPCs) motivated the development of nondestructive diagnostic methods for health monitoring of aircraft wiring. In this paper, the ABCD matrix (or transmission matrix) modeling method is introduced to derive normal and faulty load circuit models with better accuracy and reduced complexity compared to the differential equation approach, and an intermittent arc fault detection method is proposed based on temporary deviations of load circuit model coefficients and wiring parameters. Furthermore, based on the faulty wiring model, a genetic algorithm is proposed to estimate the fault-related wiring parameters such as intermittent arc location and average intermittent arc resistance. The proposed method can be applied to both the alternating current power distribution system (PDS) and the direct current (DC) PDS. Experiments using a DC power source have been conducted, and the experimental results have demonstrated effectiveness of the proposed method.