Fast Driving Cycle Efficiency Optimization of Interior Permanent Magnet Synchronous Machines Considering PWM-Induced Harmonic Losses

A multi-objective optimization framework is developed in this work to improve the driving cycle efficiency of IPMSMs, into which a fast-computational approach for PWM-induced harmonic losses is embedded. At a set of characteristic operating points, iron losses are first evaluated under sinusoidal current source (SCS) excitation using Computationally Efficient Finite Element Analysis (CE-FEA), while a Time-Stepping Finite Element Analysis (TS-FEA) spanning one quarter of the electrical period provides the copper losses. For scenarios where the machine is driven by a pulse-width modulation (PWM) voltage source inverter, the harmonic losses arising from modulation are quickly assessed through a small-signal time-harmonic finite element method (THFEA)-based model. The resulting optimization procedure seeks a trade-off between two conflicting goals: minimizing overall losses and reducing material cost. Given an equal cost level, incorporating PWM-related harmonic losses into the design loop cuts down the total loss by 3.11% relative to a baseline that only considers SCS-supply losses. The extra computational burden amounts to 17 h, representing a time rise of roughly 22.65%.