| Aircraft Integrated Drive Generator with constant speed and constant frequency is the core of power in modern large airliner. Due to the adverse high-altitude environment during flight, aircraft generator is prone to failure and then the aviation safety is threatened. So accurate and timely fault diagnosis of aircraft generator is the premise to assure safety.The paper is to be studied by two steps. Firstly, modeling and simulation is made for a single aircraft generator.The mutual influence of each loop in stator and rotor and the electromagnetic transient process are studied in-depth through analysis of the basic equations of synchronous motor, and the simulation model of motor is developed in MATLAB/Simulink software platform. The three-level generator system is built by the simulation models of motor according to the characteristics of aircraft generator. Then on this basis, one of the most important parts of aircraft generator-rotating rectifier is selected as the research object of fault diagnosis. By analyzing the failure mechanism, a classification of common faults of rectifier is made and the fault model is built. The field current of the exciter is extracted as fault-detection signal of rectifier. After Fourier decomposition for this signal, its characteristics are extracted for further analysis, laying the foundation for further fault diagnosis.The steady and dynamic characteristics of aircraft generator during its normal working condition can be simulated on this developed simulation model of system and the failure working condition can also be simulated on it. The simulation model can make a contribution to analysis and design of aircraft power system and also provide a good platform for virous fault diagnosis of aircraft generator and then provide new ideas for improving the maintenance efficiency of aircraft generator. |
