Dynamics modelling and vibration response of wind turbine gearbox under varying loading and MPPT control

Vibration response of wind turbine gearbox is unsteady and nonlinear due to the variable wind speed and MPPT control actions. Varying load and nonlinear vibration bring challenges for wind turbine gearbox vibration control and fault diagnosis. In this paper, a wind turbine gearbox dynamics model is developed to analyse vibration response of gearbox under varying load and MPPT control. Vibration of gearbox under the varying load and faulty gear conditions is achieved via numerical simulation. By incorporating the mathematical derivation and dynamics simulation, the results show the vibration signal of wind turbine gearbox under varying load and MPPT control can be linearised and normalised by processing the root mean square (RMS) of vibration signal. We suggest the slope of the RMS1/4 value against wind speed as a useful indication for fault diagnosis of wind turbine gearbox.