Exact analytical prediction of magnetic field in a hybrid and wound excitation synchronous machine

This paper presents an analytical method for computation of magnetic field distribution and electromagnetic performances in salient pole synchronous generators. A 2D exact analytical solution of magnetic field distribution is established. It involves solution of Laplace´s and Poisson´s equations in stator slots, airgap and rotor excitation slots. Obtained exact analytical results of open circuit, armature reaction, on load magnetic field distribution, flux linkage, back-emf and self inductance are verified with those issued from finite element method (FEM). Assist effects by additional permanent magnets in salient-pole synchronous generators are also investigated analytically, even if these effects are present only for deep saturated machines.