Magnet Synchronous Motor For Electric Vehicle Research Articles

Comparison and Experimental Verification of Different Approaches to Suppress Torque Ripple and Vibrations of Interior Permanent Magnet Synchronous Motor for EV

Interior permanentmagnet (IPM) motors have been the most promising solutions for electric vehicles (EV) drives in terms of torque/power density, compactness, and efficiency. However, IPM motors are vulnerable to large torque ripple and high-level electromagnetic vibrations due to the differences of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d-&amp;q</i> -axis inductance and abundant spectrum of exciting forces. This article presents an intensive comparison of IPM motors with three design approaches to reduce cogging torque, torque ripple, and electromagnetic vibration. The design approaches compared cover skewing slot and segmented rotor approaches commonly used in industry, as well as a new asymmetric pole approach. A commercial 10 kW 8-pole/ 48-slots V-shaped IPM motor for EV traction is taken as the reference base. Extensive performance comparisons, including cogging torque, back-EMF, load current, load torque profiles, PM reliability, and torsional force were carried out. Besides, vibration aspects in terms of exciting force, modal property, and electromagnetic vibration response were also analyzed and compared. Finally, the prototypes with the mentioned three design approaches are produced, respectively, and intensive experimental tests were done to verify the analysis and comparison.

Design Consideration of Fractional Slot Concentrated Winding Interior Permanent Magnet Synchronous Motor for EV and HEV Applications

This paper presents a comprehensive study on the fractional slot concentrated winding (FSCW) interior permanent magnet synchronous motors (IPMSMs) with different pole slot combination for the application of electric vehicle (EV) and hybrid electric vehicle (HEV). Three motors with the same dimension constraint and rated parameters are designed and optimized. With the optimized motors, winding factors and magnetomotive force (MMF), inductances, torque capacity, constant power speed range (CPSR), the losses, the efficiency, demagnetization capability and vibration are investigated and compared. The comparison results show that 12/8 motor and 12/10 motor have their respective unique advantages while 12/14 motor is not as good as the others.

Multi‐objective optimisation design and performance comparison of permanent magnet synchronous motor for EVs based on FEA

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.

Improved Direct Torque Control of Permanent Magnet Synchronous Electrical Vehicle Motor with Proportional-Integral Resistance Estimator

Electric vehicles (EVs) require fast torque response and high drive efficiency. This paper describes a control scheme of fuzzy direct torque control of permanent magnet synchronous motor for EVs. This control strategy is extensively used in EV application. With direct torque control (DTC), the electromagnetic torque and stator flux can be estimated using the measured stator voltages and currents. The estimation depends on motor parameters, except for the stator resistance. The variation of stator resistance due to changes in temperature or frequency downgrades the performance of DTC, which is controlled by introducing errors in the estimated flux linkage vector and the electromagnetic torque. Thus, compensation for the effect of stator resistance variation becomes necessary. This work proposes the estimation of the stator resistance and its compensation using a proportional-integral estimation method. An electronic differential has been also used, which has the advantage of replacing loose, heavy, and inefficient mechanical transmission and mechanical differential with a more efficient, light, and small electric motors that are directly coupled to the wheels through a single gear or an in-wheel motor.