The Research Of Vibration Monitoring And Fault Diagnosis Method For Wind Turbine Gearbox

Wind is regard as the key of national development strategy,because its advantage is a clean and renewable energy used to generate electricity at home and abroad.Gearbox located in remote areas around with extreme environment is easy to get out of order,which has a direct impact on generating capacity and economic benefits.Therefore,it is of great significance to design and study the monitoring and fault diagnosis method for wind turbine gearbox.Gearbox in doubly fed wind turbine is study object in this paper,and the method of condition monitoring and fault diagnosis is mainly analyzed.The following is the main work of this paper:(1)Structure and fault signal model of gearbox is mainly studied,and the structure contains two-stage planetary one-stage parallel-shaft and one-stage planetary two-stage parallel-shaft gearbox.Fault characteristic frequency is calculated though gearbox physical parameters,which is criterion of fault diagnosis later.(2)When gearbox is monitored by RMS,normal distribution pretreatment method,which removes the impact noise in the vibration signal to calculate RMS,is to solve problem of RMS error cause by high energy instantaneous impact noise under sudden change of wind speed and load.This method can effectively reduce the impact on RMS,and processed RMS accurately reflects the vibration state of the gearbox.(3)According to the principle that gearbox fault vibration is a modulating signal and fault characteristic frequency is modulated to engagement frequency or natural frequency,extract fault characteristic frequency through amplitude demodulation and frequency demodulation to locate fault accurately.(4)Waterfall is used to achieve the goal of condition monitoring and fault diagnosis,which solves the problem that spectrum and envelope spectrum do not contain time information.Determine fault position and time successfully through changes of frequency band in waterfall.