Optimized Transient Simulation of Moving and Rotating Electrical Machines Using ANSYS
The simulation of electrical machines is done in several steps. First the construction is to be done using the bottom up or top down method resulting in a model consisting of components, volumes, areas, lines and points with different properties according air, steel, aluminium or copper. Within the second step the meshing is done respecting areas with high magnetic work such as the airgap with very small Finite Elements. After finishing the model with border conditions and loads within the third step the user may analyze his problem. Following this way the user can do static and harmonic calculations in a short time, a user friendly menu is helpful. The problem of those Finite Element simulations is the impossibility to simply change parameters such as airgap distance, machine diameter or yoke thickness. On the other hand motion of machines, that is the moving of the rotor within or towards the stator according, or the changing voltages or currents at the windings is impossible. To do those electromagnetic simulations the engineer needs a Finite Element System with macro language and changeable parameters, electromagnetical elements such as voltage or current sources, resistors, inductances and coils to switch the elements of the Electrical machine together to a complete system, methods for building sliding interfaces between stator and rotor according the motion of the machine and at least the transient analyzation method. ANSYS as a multipurpose and multiphysical Finite Element System includes all features for building moving 2D and 3D models of Electrical machines taking switching and changing of voltages and currents into account. In the following chapters the simulation of two different types of Electrical Machines, one is a synchronous linear induction machine, the other is a rotating DC machine taking the commutating process into account in 2D is explained.