The Fault Diagnosis Of Gear Box For Wind Turbine Generator System

Wind energy is a clean renewable energy. Gear box is the core part of transmission gear of wind turbine generator system. Its operation status will affect the efficiency of the whole wind turbine generator system. As a result, the research of the fault diagnosis of gearbox is very necessary. The influence of oil temperature is analyzed. The basic theory of the wavelet packet analysis and the principle of the wavelet packet fault diagnosis are discussed. The wavelet packet analysis and spectral analysis are introduced. The theory of fault diagnosis based on the wavelet packet analysis is put forward too. A new fault diagnosis method is bringed forward. It is applicated in the fault diagnosis of gear box based on the software of Matlab,and its feasibility is approved.Firstly the significance and status of gear box of wind turbine generator system is introdused in this paper. Then, the fault types,fault causes and fault diagnosis are introduced too. In this paper, Application development of fault diagnosis is given. The fault characteristics of gear box are analyzed.Secondly, to obtain the characteristic of the fault of vibration for the gear box of wind turbine generator system, the models of gear and double gears are established in the sofaware of Ansys.We obtain the frequency and stress of the gear by simulation using the software Ansys.Thirdly, the characteristic of the fault of high oil temperature is studied. Gear fault is one of the common faults, which may cause the mechanical equipment not functioning properly. If the gear goes wrong and has failure such as high oil temperature, it will impact the performance and reliability of other components of wind turbine generator system. When cylindrical gear is working, if the oil temperature is much higher, some failures such as scuffing and tooth surface damage will occur. This paper uses the analysis software (ANSYS) to make transient thermal and model analysis of the cylinder gear and to determine the temperature distribution, the thermal deformation under normal and abnormal condition, which is beneficial to found the fault characteristics and diagnostic way of the gear box.The wavelet packet is advocated in these days,which is used in mechanical fault diagnosis. The wavelet packet has a better signal resolution than the wavelet transformation and it is much better than wavelet transformation in analyzing signals of high frequencies. Wavelet packet can obtain different fault information from different frequency signals respectively. In this paper, one fault diagnosis method which is based on wavelet packet arithmetic and spectral analysis is presented. The software Matlab is used to diagnosize faults of the gear box and the simulation analysis of several faults with the Matlab is carried out. The result shows that this method is very effective.Wind generation is the most developed energy technique,and it would become an important replacement energy of the conventional energy. In all the parts of wind turbine goes wrong most easily. Diagnose gear faults accurately is very critical. The study of the fault diagnosis is important in theory and valuable in application. The simulation experiments presented in the paper verified that this method has excellent performance.