Design of a spoke-type permanent-magnet motor with optimal winding configuration for electric vehicle applications

Abstract

The spoke-type motor has higher torque density than the conventional one resulting from its structure for concentrating flux from permanent magnets (PMs). However, this motor suffers from the serious distortion of back electromotive force (EMF). This paper proposes a cost-effective approach to design a spoke-type motor with lower harmonics of back-EMF for electric vehicle. The key is to superimpose the coil-EMF of one phase in such a way that the harmonics of the phase-EMF can be canceled, resulting in essentially sinusoidal waveforms. By using finite element method (FEM), an optimal coil-EMF vectors distribution for minimum harmonics of the phase-EMF is obtained and verified. In addition, the co-simulation technology is adopted to verify that the torque ripple under the optimal winding configuration can be significantly suppressed.

Decoupling control for five-phase fault-tolerant permanent-magnet motor by using SVM inverse system method

“…After using the lagrange function, duality principle and kernel function theory, the problem transforms into a quadratic programming problem. It can be rewritten as: 1 1…”

“…However, in some high performance applications like electric vehicles and aerospace applications, high reliability and continued operation are required. So, fault-tolerant permanent-magnet (FTPM) motor has been investigated and used [1]. FTPM motors has not only the common features of permanent magnet motor, but also the characteristic of physical isolation, thermal isolation, magnetic separation, electrical isolation and inhibition of short circuit current.…”

Comparison between a spoke-type PMSM and a PMASynRM using ferrite magnets

“…Figure By doing this, the magnet faces are large and able to push great levels of flux density towards the machine's airgap [10]. This concentration of the flux allows the machine to achieve an airgap flux density that is as high as that of a rare earth magnet motor [11] which helps it to achieve a higher torque density [12]. Thus, these machines are suited for both rare earth magnets, such as NdFeB, and also for ferrite magnets.…”

“…This machine design is used by Honda in Electric Vehicle applications [10]. Some drawbacks found in this type of machine design include a restricted Field Weakening operation at high speeds, risk of irreversible demagnetization of the permanent magnets [11] and distortion of the Back EMF waveform [12]. Figure 1 shows the location of the d and q axes in a spoketype PMSM and the direction magnetic flux lines in a spoketype PMSM..…”

Characteristic Analysis and Experimental Verification of Electromagnetic and Vibration/Noise Aspects of Fractional-Slot Concentrated Winding IPMSMs of e-Bike

“…Moreover, the spatial distribution of the radial force is affected by the stator and rotor, and its magnitude changes with time; thus, the radial force generates a vibration frequency that affects the vibration. This makes it possible to predict the electromagnetic noise/vibration characteristics generated by the motor [20][21][22][23][24]. If the noise and vibration characteristics of the motor are predicted through this method, not only the noise and vibration characteristics of the motor can be identified in the design stage, but also a more mechanically robust design can be made.…”