Bridge-Selective Saturation-Guided Topology Optimization Within a Hierarchical Framework for IPMSM Rotors

Abstract

This article proposes a novel bridge-selective saturation-guided topology optimization (TO) method for interior permanent magnet synchronous motor (IPMSM) rotors within a hierarchical optimization framework. First, the outer-loop parameter optimization provides a baseline rotor configuration, and the nonlinear magnetic behavior of the rotor core is incorporated into the TO framework through a saturation-consistent material interpolation model. Then, the effects of element variation on the saturation states of both the main flux path and the flux-barrier bridge region are simultaneously considered. Next, a region-dependent saturation indicator is embedded into the sensitivity analysis and design updating scheme, such that excessive saturation in the main flux path is suppressed while a higher saturation level in the flux-barrier bridge region is promoted to increase local magnetic reluctance and reduce leakage flux. Finally, a 3-kW IPMSM prototype is built to validate the proposed method, demonstrating its effectiveness and accuracy.