Combining field and circuit equations for the analysis of permanent magnet AC motor drives

A finite-element formulation for modeling permanent-magnet synchronous machines by combining the field and circuit equations is presented. For an optimized and reliable operation of a machine, an accurate prediction of the magnetic field distribution is required. The field and circuit are coupled, giving a set of nonlinear time-dependent equations, a solution of which gives the magnetic vector potential at every nodal point and the electric field intensity at the conductor nodal points. The model can be used to perform any desired tests and to calculate operational parameters in both steady-state and transient operation, when the machine is fed from any power supply.<>