Topology Optimization Framework for Simultaneously Determining the Optimal Structural Design and Current Phase Angle of the IPMSMs for the MTPA Control

Abstract

Although it is crucial to design the magnetic flux path and the maximum torque per ampere (MTPA) current reference under the current limitation, it is challenging to simultaneously consider these features in developing an interior permanent magnet synchronous motors (IPMSM) due to complicated coupling effects. In this study, to overcome the above issue, the motor-design parameters are estimated by conducting electromagnetic finite element (FE) analysis two-times at every iteration of topology optimization. Then, the MTPA current phase angle can be analytically expressed in terms of an element-wise relative density (i.e., design variable in topology optimization). In addition, the structural safety is assessed by conducting the structural FE analysis under design-dependent loads to reflect a high-speed rotating condition. The proposed two-stage topology optimization enables to simultaneously optimize both a structural design and current phase angle to achieve the maximum electromagnetic performance. The structural safety and manufacturability are also considered to obtain a practically meaningful design. With two different types of permanent magnet, the optimized IPMSMs are obtained and manufactured to validate the proposed method. Simulation and experimental results demonstrate the validaty and potential of this work.