Simulation and Methodologies

  Numerical calculation with in-house built solvers Copyright: IEM

The workgroup Simulation and Methodologies deals with the analytical computation and the numerical simulation of electrical machines and applications in electromagnetic energy conversion. Within the workgroup all fields of interest, that are necessary in relation with the design, construction and optimization of electromagnetic energy conversion, are considered. Apart from electromagnetics, structural dynamics and acoustics as well as the thermal behavior of energy converters, the focus of the investigations is in particular the combination of different domains in the form of multi-physical system simulations. For these investigations, methods in the field of analytical modeling, numerical finite element methods and rapid solver prototyping are used, developed and advanced.

The IEM can rely on a well-founded experience in the development of its own calculation tools. For example, iMOOSE provides an innovative, modern and object-oriented software library based on the finite element method for numerical field calculations. When solving static, harmonic and transient effects, this library enables on the one hand the consideration of ferromagnetic effects, anisotropy effects, eddy current effects and linear and rotating movements and on the other hand the calculation of electromagnetic quantities such as torques, fluxes, inductivities and magnetic forces. Parameterized models enable the simulation in the two- and three-dimensional range under consideration of geometric variations, eccentricities, mis-magnetizations and other influences such as skewing or deformation. The great advantage of this solver environment, which was developed at the IEM, compared to commercial software is the very detailed knowledge of the implemented methods, the access to all functions of the solver and the possibility to integrate newly developed methods efficiently.

To reduce the model orders of the used finite element models, which enables real-time simulations, methods of model order reduction like Proper Orthogonal Decomposition or Proper Generalized Decomposition are developed and applied.

Within the framework of multiphysical system simulation, the models and calculation methods of different physical domains are combined. In this context, for example, a time-transient system model of the drive train was developed, which, in addition to the electrical machine, also considers power electronics, control, sensor technology and mechanics. In addition to saturation effects, stator and rotor slotting as well as the temperature, the modeling of the machine also considers manufacturing influences. With this model, questions in the field of acoustics can also be answered by analyzing the electromagnetic force excitation and combining it with a structural-dynamic model.

In addition to the simulation and calculation of problems in electromagnetic energy conversion, the focus of the workgroup is also on the representation and visualization of global and local quantities, such as electromagnetic potentials, fluxes, forces and losses.

Due to the close cooperation with the other workgroups, the development of flexible simulation tools and methods as well as sophisticated calculation models is one of the core competences of the IEM.