A comparative study of methods for modelling the structural stiffness of generator components

Abstract

Direct-drive generators are low speed electrical machines requiring robust and large supporting structures designed to resist the significant loads present during assembly and operation. Generator structures have to be stiff, especially in the radial direction for radial-flux machines. This paper presents three different structural modelling approaches: finite element, analytical and hybrid (a combination of the results obtained from dimensional studies and finite element analyses). These are used along with models of electromagnetic active material, to parametrically calculate the minimum structural stiffness and mass of the components forming the machine.

An Efficient Computational Analysis and Modelling of Transferred Aerodynamic Loading on Direct-Drive System of 5 MW Wind Turbine and Results Driven Optimisation for a Sustainable Generator Structure

“…Rigid fixtures were taken into consideration and later compared tothe flexible fixtures, although it was assumed that flexible bearing fixtures will better portray the behaviour of the system under loading conditions. For the purpose of constraining the model and calculating the radial stiffness for individual bearings, the same approach was made as in [18], corresponding to the parallel spring theory by using Equation (1). It was necessary to specify the material properties of the created CAD models to produce accurate simulations.…”