There is a strong demand for the research of electric vehicles (EVs) in automotive industry, because of an increased concern of the energy depletion and environmental pollution problems caused by oil-fueled automotive. The traction motor drive system is one of the core components of EVs, and a motor with superior dynamic performance and high efficiency could significantly reduce energy consumption and improve riding comfort of EVs. Therefore, in order to achieve high dynamic performance and high efficiency of permanent magnet synchronous motor (PMSM), a multi-objective optimization design method for PMSM based on the artificial bee colony algorithm was proposed in this paper. First, based on the magnetic field analytical model of PMSM, the analytical expressions of the key parameters were deduced, namely, mechanical time constant and electrical time constant. Second, the efficiency and electrical and mechanical time constant were defined as optimization objectives. Third, the efficiency and dynamic performance of the original motor and optimized motor were compared applying the finite-element analysis. Furthermore, one prototype machine was manufactured according to the results of optimization. The dynamic performance and efficiency of the prototype had been tested. The experiments show confident results that the efficiency increased about 1% and the mechanical time constant reduced to 31.4% of initial value.

This article proposes a novel dual-three-phase high-power high-speed permanent magnet assisted synchronous reluctance starter generator (PMaSynR SG) for aviation application, which has the characteristics of high efficiency, high power density, high reliability, and excellent antishort-circuit ability. The proposed PMaSynR SG can obtain higher efficiency and power density by embedding permanent magnet in the rotor topology compared with the synchronous reluctance generator, and has better antishort-circuit ability compared with the permanent magnet synchronous starter-generator. Moreover, design of dual-three-phase winding is adopted, which not only reduces the phase current, but also improves the reliability. In this article, the topological structure, characteristics and principle of PMaSynR SG are systematically studied at first. Second, a simplified dq -axis equivalent magnetic circuit model is established, and the expressions of dq -axis inductance and permanent magnet flux linkage are derived on the basis of the basic parameter selection. Then, combined with parameter sensitivity analysis, the influence law of rotor structural parameters on antishort-circuit ability and electromagnetic performance is revealed. Finally, a 40 kW 24 000 r/min PMaSynR SG is designed and manufactured. The simulation and experimental results show that the proposed PMaSynR SG has excellent electromagnetic performance with the power density of 3.1 kW/kg and the efficiency of 94%, while the short-circuit current is only 59% of its rated value.

With the rapid development of technology, motors have drawn increasing attention in aviation applications, especially in the more electrical aircraft and all electrical aircraft concepts. Power weight ratio and reliability are key parameters for evaluating the performance of equipment applied in aircraft. The temperature rise of the motor is closely related to the reliability of the motor. Therefore, based on Taguchi, a novel multi-objective optimization method for the heat dissipation structural design of an electro-hydrostatic actuator (EHA) drive motor was proposed in this paper. First, the thermal network model of the EHA drive motor was established. Second, a sensitivity analysis of the key parameters affecting the cooling performance of the motor was conducted, such as the thickness of fins, the height of fins, the space of fins, the potting materials and the slot fill factor. Third, taking the average temperature of the windings and the power weight ratio as the optimization goal, the multi-objective optimal design of the heat dissipation structure of the motor was carried out by applying Taguchi. Then, a 3-D finite element model of the motor was established and the steady state thermal analysis was carried out. Furthermore, a prototype of the optimal motor was manufactured, and the temperature rise under full load condition tested. The result indicated that the motor with the optimized heat dissipating structure presented a low temperature rise and high power weight ratio, therefore validating the proposed optimization method.

Zero-sequence current (ZSC) exists in five-phase open-winding permanent magnet synchronous motors (FPOW-PMSMs) with a common dc bus, resulting in harmonic current and system losses. Besides, the use of the dual-inverter increases inverter losses and induces a high-frequency common-mode voltage (CMV), damaging the bearing. This article proposes a novel ZSC suppression method for the FPOW-PMSM, which can reduce the inverter losses while decreasing the CMV. First, the average zero-sequence voltage equal to zero is considered a restriction to calculate the duration time of basis vectors. Five active vectors are selected to synthesize the reference voltage vector in each sector. Then, benefiting from abundant switching states redundancy, a novel switching states combination with minimum switching actions is proposed to reduce the CMV and inverter losses. Furthermore, the modulation range of the proposed modulation method is analyzed, indicating that the proposed method achieves considerable dc-bus voltage utilization. Finally, the experimental results verify the effectiveness of the proposed method.

In this paper, a new method is proposed to suppress the vibration caused by the modulation effect of high-order electromagnetic forces in permanent magnet (PM) motors. Firstly, the modulation effect of the radial force was investigated, which indicated that the higher-order electromagnetic force could cause modulated vibrations through the modulation effect. Then, auxiliary slots on the magnet surface and their effect on vibration reduction were investigated. The optimal shape of the auxiliary slot was found to minimize the noise of motor vibration. Finally, the method was verified experimentally.