Nonlinear finite element solution of electrical machines under no-load and full-load conditions

The magnetic field distribution in saturable iron parts of electrical machines is defined by a quasi-Poisson equation. The solution to this equation is obtained by minimizing an energy functional by means of trial functions defined in triangular subregions of the two-dimensional field region. This method is applied to an electrical machine for predicting its no-load and on-load performance. Good agreement is obtained between estimated values and test results. Under load conditions, since the pole axis is not an axis of symmetry, a new boundary condition is introduced. Graphical plots of the flux distribution for the machine under different operating conditions are shown.