Research On Fault Diagnosis Of Wind Turbine Based On Stator Current Signal Analysis

Wind energy has always been a kind of energy with great potential.Because of its clean,green and pollution-free advantages,it is becoming a new energy that countries all over the world compete to develop.With the rapid development of the wind power industry,the fault diagnosis technology of wind turbines is more concerned in the field of power generation.Because wind turbine often works in remote mountain areas,it is difficult to extract fault signals by traditional contact fault diagnosis methods.In contrast,the stator current analysis method,a non-contact fault diagnosis method,has the advantages of easy signal acquisition,less external interference and online monitoring.Therefore,it is of great engineering significance to study the stator current analysis method.The main contents of this paper are as follows:(1)Through the knowledge of electrical machinery,the common faults of wind turbine generator are theoretically deduced,and the application of stator current analysis method in fault diagnosis is deeply studied.The relationship between stator current and fault frequency of stator interturn short circuit fault,rotor broken bar fault,rolling bearing fault and transmission system misalignment fault is analyzed.(2)Based on the basic structure and working principle of the doubly fed wind generator,the mathematical model and equivalent circuit of the doubly fed wind generator are created,and the simulation model of the doubly fed wind generator is built on Matlab software.(3)The current signals of stator interturn short circuit fault,rotor bar breaking fault,rolling bearing fault and transmission system misalignment fault are simulated in the simulation model through series and parallel resistance and square wave method.(4)Through Fourier transform,Park vector method,Hilbert Huang transform,Hilbert envelope demodulation analysis and other signal processing methods in relevant fault diagnosis,the fault signal is processed and analyzed,the fault frequency is highlighted,compared with theoretical derivation,and the feasibility of generator fault diagnosis based on stator current analysis is verified.