Dynamic modeling and vibration analysis of offshore wind turbine rotor system with insulated bearing under inclined shaft current damage

Abstract

The offshore wind turbine is a device that uses the wind energy on the ocean to generate electricity. The voltage generated by offshore wind turbine can break down the insulated bearing and cause inclined shaft current damage. To explore the dynamic characteristics and influencing factors of offshore wind turbine rotor system, a dynamic model of offshore wind turbine rotor system is proposed. The insulating coating, inclined shaft current damage and contact characteristics are considered in the model. Through numerical simulation, the mapping relationship between vibration response and damage length is studied, the influence of the interaction between inclination angle and radial clearance on vibration response is analyzed, and the influence of the mass of insulating coating and speed on vibration response is discussed. The practicability of the model is proved by the experiment of physical prototype. The results show that, as the length of the shaft current damage increases from 10 × 10−5 m to 50 × 10−5 m, the strength of the vibration response increases. The coupling of the inclination angle of the shaft current damage and the radial clearance jointly promotes the enhancement of the vibration response. The enhancement effect of radial clearance is more significant than that of inclination angle. The increase of speed worsens the state of operation, and the state transitions from stable quasi-period to chaos.