The requirements of high efficiency, power density, and low price for the motor of electric vehicles (EVs) make the design of the driving motor become a process of multi-objective optimisation. For purpose of the permanent magnet synchronous motor (PMSM) used for EVs has the higher efficiency, wider range of speed regulation with flux-weakening and better cost superiority, a multi-objective optimisation design approach based on finite element analysis (FEA) and modified particle swarm optimisation (MPSO) algorithm which takes efficiency, flux-weakening rate, and price as optimisation objectives is proposed in this study. Five PMSMs with different rotor topologies (V-shape, U-shape, double V-shape, delta-shape, and double tangential-shape) are optimised by the proposed optimisation method and their performance characteristics, including flux-weakening ability, efficiency, price, and anti-demagnetisation ability, are compared. The results suggest that double V-shape rotor topology has the wider constant power range and double-layer PMs topology has stronger anti-demagnetisation ability and wider high efficiency interval, whereas single-layer topology has lower cost price. Furthermore, a PMSM prototype with V-shape PMs is manufactured, so that the feasibility of multi-objective optimisation design approach and accuracy of FEA are verified by prototype experiments.

This paper presented the design and performance analysis of a 60kW interior permanent-magnet (IPM) synchronous motor used as traction drive in a medium commercial electric vehicle (EV), according to the traction requirements of the electric vehicle under the rated operating conditions and overload conditions. The key dimensions were calculated on the basis of the permanent-magnet (PM) motor theory, and the 2D finite element method (FEM) simulation model of the IPM motor was built by using 2D Maxwell software. The influence geometric structures of the IPM motor including the PM dimensions and skewed PMs on electromagnetic torque were investigated, and the temperature distribution of the motor under rated operating condition and the condition of maximum speed were calculated. Finally, the simulation results of the IPM motor running in various operating modes were compared with the experimental results, which demonstrated that the designed IPM motor can match all requirements of the medium commercial electric vehicle driving applications.

Abstract. This paper presents the design and performance analysis of a 60kW Interior PM (IPM) synchronous motor used as traction drive in a medium commercial electric vehicle (EV). The 2D time-stepping finite element method (TS-FEM) simulation model of the IPM motor is built by using 2D Maxwell software. The geometric structures of the IPM motor are optimized, and the operational performances of the IPM motor running at full speed range are investigated. Finally, the experimental platform of the prototype motor and its controlling system are set up. The performance comparison of the experimental results and simulation results of the IPM motor running in various operating mode are reported. All the results show that the designed IPM motor can match all requirements of the medium commercial electric vehicle driving applications.

In order to improve the utilization of PM in electric machine, this paper focus on the performance analysis of a coreless axial-flux PM machine with four types of Halbach PM arrangement. A 3-D FEM model is built and the flux distribution, electromotive force waveforms, output torque, core losses, and efficiency of the four types of Halbach PM arrangement machines have been investigated.

This paper presents flux modulation permanent magnet machines with four topologies, which have incorporated the magnetic gear structure and a stator within one machine. Four types of flux modulation permanent magnet machines are compared quantitatively. According to the location of the four structures, the four proposed machines are referred as motor I, motor II, motor III, and motor IV. This paper focuses on the performance comparative analysis of the four proposed machines by using finite element method (FEM). The output electromagnetic torque, induced voltage, cogging torque and efficiency of the four proposed machines have been investigated.