Abstract
A six-phase motor with a high degree of freedom can be converted into a three-phase motor in order to be used in a traction system. In addition, when phase-change technology is applied, it is possible to establish an efficient control strategy tailored to the driving environment of the EVs. Therefore, in this paper, a down-scaled 3 kW permanent-magnet-assisted synchronous motor (PMa-SynRM) capable of phase switching was designed, and its driving states in controlled fault modes were analyzed through experiments. The PMa-SynRM selected for this study was a machine that had good fault-tolerance capabilities and was less expensive than an IPMSM with the same performance; it was designed using the lumped-parameter method (LPM) having a fast calculating speed and a genetic algorithm. In addition, the effectiveness of the optimal design was verified by comparing the analytical results of the FEM and the LPM. Lastly, a phase switching experiment was conducted to analyze the steady-state and transient-state characteristics, and the results are presented.
Highlights
A three-phase induction machine (IM) is a structure that is simple and widely used in industry
A permanent-magnet synchronous machine (PMSM) applied to a hybrid electric vehicle (HEV) has a higher power density-to-volume ratio than an IM, so it is valuable as an alternative electric motor to the IM in terms of the environment and fuel consumption [11]
The back electromotive force (BEMF) is voltage induced when the magnetic flux generated in the permanent magnet is linked to the coil of the stator when the motor rotates under no-load conditions, and can be expressed as the product of the flux linkage and the nents analyzed through FFT did not change, and the relative torque pulsation level could be estimated through the size of the harmonic components
Summary
A three-phase induction machine (IM) is a structure that is simple and widely used in industry. Efficiency can be greatly reduced due to the loss of short-circuit current flowing internally within the rotor, and there is the disadvantage of a low-torque characteristic in the low-speed region [1] These disadvantages have been improved through research on multiphase IMs with higher output power and reliability as power electronics technology developed [2,3,4,5,6], and the use of IMs in electric-vehicle (EV) traction applications such as trains, ships, and automobiles was expanded [7,8,9]. This paper investigated the optimal design of a 3 kW six-phase down-scaled model of a PMa-SynRM type, which could respond flexibly to fault situations, had excellent traction, and reduced PM usage; it was conducted using LPM and the genetic algorithm, and fault-tolerant capability was confirmed by analyzing the load characteristics for six- and three-phase operations. If the magnetic flux, current, and inductance are designed properly in the torque, as shown in Equation (1), output torque can be improved
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
