Design Optimization for Segmented Dual Three-Phase Electrical Machines with Magnetic Asymmetry

Dual three-phase electrical machines (DTEM) offer additional degrees of freedom in the design optimization process. In this paper, segmented asymmetrical machines (SAM) as a type of DTEM are investigated. A surrogate model approach to optimize the magnetic design of permanent magnet synchronous machines is discussed. The two machine systems are regarded separately and fed by independent inverters with the benefit of optimizing each three-phase system independently. A resulting DTEM is characterized by an asymmetric geometry and operation. Surrogate models are trained, several multi objective optimizations are performed resulting in Pareto optimal solutions. For different proposed objectives the advantages and disadvantages of asymmetrical segmentation in dual three-phase electrical machines are discussed. The magnetic coupling between the systems is analyzed in detail and effects on efficiency, torque and harmonic components are investigated and optimized.