Flux-barrier design technique for improving torque performance of interior permanent magnet synchronous motor for driving compressor in HEV

This paper presents flexible flux-barrier designs in an interior permanent magnet synchronous motor (IPMSM) for driving compressor in hybrid electrical vehicle. A conventional single-layer IPMSM model, a popular double-layer IPMSM model and a proposed novel double-barrier IPMSM model are built and optimized for improving torque performance by reducing cogging torque and torque ripple. The novel double-barrier IPMSM has beneficial attributes of simplest single-layer PM and flexible double pairs of flux-barriers in IPM rotor design. The optimal geometries of flux-barriers in each IPMSM designs are determined by response surface methodology (RSM). The cogging torque and torque ripple of IPMSM model are calculated using finite element analysis (FEA), and confirmed by test. Finally, the effectivity of the novel double-barrier IPMSM design on torque performance improvement is well proved, and its advantages are emphasized.