Dynamic modelling and dynamic characteristics of wind turbine transmission gearbox-generator system electromechanical-rigid-flexible coupling

The design of large wind turbine drivetrain systems is trending towards light weight and integration. To ensure the safe operation of the drivetrain system, investigating the electromechanical–rigid–flexible interaction of wind turbine transmission systems is necessary. This study proposed an electromechanical–rigid–flexible coupling dynamic model that can be used for variable speed and load operating conditions. The model considered the time-varying mesh stiffness, structural flexibility, magnetic saturation characteristics, and electromagnetic radial force. The effects of the flexibility of the housing and high-speed shaft on the electromechanical interaction of the system under steady and unsteady conditions are discussed. There is a strong coupling between the gear system and the generator system. The resonance speed at the generator is affected by the gear excitation, and the vibration signal of the gear system is affected by electromagnetic excitation. The flexibility of the high-speed shaft and housing has apparent effects on the vibration characteristics of the integrated systems. It directly affects the stability and safety of the system particularly under gust conditions. Thus, studying the electromechanical–rigid–flexible coupling characteristics is significant for wind turbine drivetrain design.