Finite-Element Field Analysis of an Inhomogeneous, Anisotropic, Reluctance Machine Rotor

The appropriate form of the Poisson equation, for a region that is anisotropic and continuously inhomogeneous, is derived. A practical example is furnished by the axially laminated anisotropic rotor of a reluctance machine. A functional is presented which is made stationary by the solution of the Poisson equation under natural Dirichlet, mixed, and Neumann boundary conditions. Because of anisotropy, the latter two boundary conditions involve B rather than ∂ϕ/∂n . The finite element scheme caters for curves along which the boundary condition may vary continuously. Results presented include air gap flux and magnetic potential plots for both the direct and quadrature-axis positions.