Research Of Aircraft IDG Fault Detecting Method Based On Short-time Fourier Transform

With the great development of aviation industry, aircraft as an efficient and convenient transportation become more and more important in modern life. At the same time, the safety of aircraft becomes essential. The main module of the Integrated Drive Generator(IDG) in main power system of the aircraft concludes the Constant Speed Drive(CSD) and exciting systems. The interference may exist and be caused by fault, harmonic, noises and the change of the loads to affect the quality of the supporting power. Therefore, aircraft IDG performance testing of the main power system has a very important significance for ensuring the safe operation of aircraft.The following six branches of fault catalogs has been researched in this paper: the fault of over/under the frequency caused by CSD faults, the interference of harmonic by alternating exciting equipment, internal short/cut circuit, low or high voltage fault by the lack of certain phase, high level current by the loads hurry change. And on this basis, the detection by widely used FFT(Fast-Fourier Transform) or WT(Wavelet Transform), can not identify the fault source effectively or accurate the quality of aircraft electricity supporting accurately, to aircraft power system. Moreover, the direct result of detection is hard to understand and thus needed to be dealt with by further disposal, which reduces the efficiency and the cost of the detection.As a result, STFT(Short-Time Fourier Transform) is used as a tool of time-phase transformer in this paper. STFT may achieve the effective intelligent diagnosis of IDG fault in aircraft electricity source, because of the combination of the information between time-phase and frequency-phase and the overcoming the deficiency of FFT and WT. Finally, the simulation result which proves that the diagnosis method based on STFT can diagnose the fault of aircraft IDG effectiveness.