A new rotor structure for line start permanent magnet synchronous motor

This work presents a new interior rotor type permanent magnet synchronous motor with direct on line starting ability, which employs both circumferentially magnetized as well as radially magnetized magnets, and consequent pole concept resulting into better steady state performance. Two dimentional (2D) time-stepping finite element analysis (FEA) has been employed in prediction of transient and steady state performance. The experimental prototypes of line start permanent magnet synchronous motor (LSPMSM) using proposed magnet arrangement in the rotor, have been developed, tested and validated in the laboratory. Simulation and experimental results indicate that the proposed magnet arrangement gives improved performance, than other magnet arrangements previously used for this machine, for a given magnet volume.