Validation of a Time-Harmonic Numerical Model for Solving Magnetic Field in End Region of a Radial-Flux Machine

We present an analysis of the magnetic field in the end region of a radial-flux rotating machine. In numerical simulations, we used three familiar boundary conditions to replace the modeling of the end shields and frame. We made measurements for comparison, and the simulation results were quite consistent with the measurements. Our analysis shows that the eddy current in the end shields and frame influences the magnetic field in the end region slightly and that the use of a homogeneous Neumann boundary condition or a standard impedance boundary condition (SIBC) to replace the end shields and frame can solve the magnetic field in the end region more accurately than a homogeneous Dirichlet boundary condition. Validation by the measurements demonstrates that 3-D current-driven time-harmonic model with suitable boundary conditions can be used to solve the magnetic field in the end region quite accurately.