Research On Feature Extraction Method For Rotating Rectifier Of Aircraft Generator

As the rotating rectifier is the core component of a synchronous AC generator,its diodes are affected by the generator vibration acceleration,centrifugal acceleration and mechanical stress because the rotor rotates in high speed.So the rotating rectifier is easy to fail.Synchronous AC generators are widely used in aerospace,national defense,industry and agriculture and other important areas,so the fault diagnosis of the rotating rectifier in synchronous AC generator is of great significance.In this paper,the fault diagnosis method of the rotating rectifier based on Fractional Fourier Transform is studied.The main contents are as follows:Firstly,the basic structure and working principle of the synchronous AC generator are introduced,and the simulation model of the synchronous AC generator is established by using Matlab/Simulink.We preform simulation experiments and analyze the simulation results under different fault modes.Secondly,we use Fractional Fourier Transform to analyze three-phase output voltage signals of synchronous AC generator and extract two key features which are important for highlighting the fault modes of rotating rectifier.In this paper,we present a fault diagnosis method for synchronous AC generator rotating rectifier and the proposed method is verified by simulation experiments.The results show the effectiveness of the proposed methods.Finally,we build a physical experiment platform of synchronous AC generator and its three-phase output voltage signals under different kinds of failure modes are verified.The experiment results demonstrate the feasibility of the presented method.This fault diagnosis has advantages of fast speed and high diagnosis accuracy.In addition,we compare the proposed diagnosis method in this article with the diagnosis method based on Fourier Transform and the diagnosis method based on Wavelet Transform.The result demonstrates the validity of the presented diagnosis method.