Optimization of a 12-Slot/10-Pole, Asymmetrical, Six-Phase IPM Considering Healthy and Open-Phase Fault Post Operation in EV Applications

Permanent magnet (PM) machines equipped with fractional slot concentrated windings (FSCW) offer a compelling solution for electric vehicles (EVs), boasting high torque and power density, high efficiency, a wide operational range, and several other advantageous features. However, faults can impair the magnets' performance, leading to significant issues that negatively affect the EVs' performance and worsen motor reliability. Although fault tolerance can be maintained through innovative control schemes to meet specific performance criteria, these solutions often introduce side issues, such as torque ripple. While extensive studies have focused on mitigating these side issues through control techniques, incorporating solutions at the design stage remains underexplored. This paper presents the design and optimization of a 12-slot / 10-pole permanent magnet synchronous motor (PMSM) aimed at achieving high-quality operation in both healthy conditions and post fault operation under an open-phase fault. A finite element-based multi-objective optimization using a genetic algorithm is proposed to optimize the machine by maximizing average torque and minimizing torque ripple during both healthy operation and in the case of an open phase fault. Embarking on an exploration of diverse rotor topologies and their implications, this study engages in comprehensive theoretical and simulation analyses. The research initiative involves the design and simulation of a 15-kW Interior Permanent Magnet (IPM) motor, crafted to emulate the characteristics of a practical light-duty Electric Vehicle (EV). To validate the conceptual framework, empirical testing is conducted using a 2-kW laboratory-scale Surface-Mounted Permanent Magnet (SPM) motor.