Numerical modeling of electrical machines and its application

A general approach to directly couple finite element models with arbitrary electric circuits is presented for the application of electrical machine. Both 2D and 3D transient finite element models are described with emphasis on the coupling using the 3D T-/spl Omega/ formulation. In the 3D model, the derivation of the induced voltage is an integral part of the coupling approach and links the magnetic field and the electrical circuit together. The system of electric circuits is created automatically and graph theory is used to deduce circuit using tree/cotree and loop analysis. The resulting field equations and circuit equations are coupled together and solved simultaneously at each time step in the time domain. A brushless DC motor drive, a permanent magnet synchronous motor drive, and a three-phase power transformer with rectifier and load circuit are provided as application examples.