Research Of Fault Diagnosis Technology Of Wind Turbine Gearbox Based On Spectral Curtosis And Resonance Demodulation

The development of renewable energy is an important measure of China's economic development strategy,and the investment of wind turbines is also increasing.But so far,China's major wind turbine manufacturers still lagging behind the developed countries,and the operation conditions of wind turbines are worse which result in a higher failure rate.The application of the condition monitoring and fault diagnosis system in the wind turbine can realize the fault prediction,fault type screening and fault location,thus greatly reducing the losses caused by the fault,therefore,the fault diagnosis and analysis of wind turbine has great significance to the rapid development of wind turbine.Gear box has the highest fault rate in wind turbine,as the fault diagnosis object,the difficulty of the gear box includes the complicated working condition,the complex structure of the transmission system,the difficulty of signal acquisition and so on,fault diagnosis of wind gear box has become a new research hotspot in the field of fault diagnosis.In view of this hot issue,the following aspects have been studied in depth:In this paper,the influence of wind power on the fault of wind turbine is analyzed from the view of dynamics,the influence of the power input to the wind turbine on the special condition is studied,the inner cause of the hight fault rate of wind turbine gearbox is studied,the effect of the buffer structure on the reduction of failure rate is analyzed.After defining the particularity of the operation environment of the wind turbine.The natural frequency of the gear which is the core transmission part of the wind turbine is analyzed,the influence of wind force on the natural frequency of the key components of the transmission system is analyzed,the natural frequency and its variation of the wind turbine under the dynamic condition are obtained.The main purpose is to study the inherent properties of wind generator change in special conditions,to differ the change of inherent properties of rotating mechanical parts under normal conditions,what important is it provides the basis for the accuracy of vibration diagnosis.The vibration signal of wind turbine is acquisited,based on the immune algorithm,the optimization of wind turbine's gearbox vibration sensor placement is studied.The gear box vibration coordinate system is constructed,optimal path of vibration transmission was calculated to determine the optimum measuring point,the optimal placement of sensors is realized.The optimum position of the vibration sensor of the wind turbine gear box is obtained,which ensures the best quality to the vibration signal.The vibration of the signal is analysised based on the resonance demodulation algorithm with Fast Kurtogram,solves the problem that the resonance frequency and the bandwidth of the filter need to be selected manually when the signal is demodulated,by using kurtosis automatic filter parameter maximization principle,to make up for the lack of manual intervention brought.From the above analysis,the driving rotating prestress change will lead to offset the inherent frequency of the system,the frequency shift in the process of diagnosis is corrected,the effects of operation conditions on the intrinsic properties of the components of the wind turbine drive is eliminated,and the more accurate diagnosis is realized.Matlab and VB are combined to develop a fault diagnosis system for wind turbines,The communication module is connected with the lower computer by RS-232 standard serial communication,and the system integration of the wind turbine fault diagnosis is realized.At the same time,developed the panoramic monitoring system of wind generator with the streaming media technology,with the fault diagnosis system,the problem of large amount of monitoring system of data storage and data analysis is solved,the fault diagnosis of fan to achieve a more intuitive effect.According to the operation characteristics and fault characteristics of the wind turbine,to fit the combined wind speed by the Weibull distribution,the wind speed model established by MATLAB and the transmission system established by UG are coupled,virtual joint simulation test system is built,The wind speed model established by MATLAB is converted to the speed and torque,then input them to the transmission system model established by UG,considering the contact parameters of transmission system.Virtual simulation platform realizes the simulation of wind turbine power input,transmission system,and the fault signal output,through the comparison of data of the real test,to prove the accuracy of the virtual test platform,provide important support for the research of fault diagnosis and test set.For the above research,the theoretical basis of fault diagnosis,the diagnosis algorithm,the signal acquisition and diagnosis system,and the virtual test system of the fault diagnosis of wind turbine are reaserched,which provides a systematic method for fault diagnosis of wind turbine.