Optimized Pulse Patterns for Anisotropic Synchronous Machines with Improved Current and Torque Properties

Abstract

Accounting for the anisotropy of interior permanent magnet synchronous motors (IPMSMs) during the computation of optimized pulse patterns (OPPs) improves the current quality but at the cost of increased low-order torque harmonics. To address this issue, this paper reformulates the OPP problem such that both the current and torque harmonics are kept as low as possible. To do so, the current harmonics that result in pronounced torque harmonics are constrained in the optimization process. As demonstrated with the presented numerical results, the proposed OPPs manage to simultaneously produce current and torque of high quality over a wide range of operating points.