Research and Application of Fault Diagnosis in Maintenance of Civil Aviation Aircraft AC Power System

AC power system is like the “lifeblood” of civil aviation aircraft, silently delivering energy to every corner of the aircraft and maintaining its normal operation. Regarding the two main components of AC power system: IDG and APU, during their entire life-cycle, in addition to the operational status, it also includes the maintenance/repair process. When IDG and APU enters the engineering repair works for fault inspection and analysis, its maintenance procedures usually involve first a visual inspection, followed by a more detailed disassembly inspection. In order to minimize the disassembly inspection, various fault diagnosis methods were studied, the existing fault diagnosis methods mostly rely on signal processing technology and the steps are tedious. In order to provide guidance for the disassembly inspection of the equipment before the disassembly check of IDG and APU, a fault diagnosis method based on StressWave analysis technology was studied, which could directly extract the fault features from the original time-domain data and frequency-domain data. Through actual test cases, the simplicity and effectiveness of this method have been verified.