This paper investigates and compares the torque-generating capabilities and electromagnetic performance of advanced non-overlapping winding induction machines (AIM), conventional induction machines (CIM), and interior-permanent magnet (IPM) machines for electric vehicle (EV) applications. All investigated machines are designed based on the specifications of the Toyota Prius 2010 IPM machine. The steady-state and flux-weakening performance characteristics are calculated by employing the 2D finite element method and MatLab, and the obtained results are quantitatively compared. Furthermore, the torque-generating capabilities of three machines are investigated for different electric loadings, and the machine having the highest torque-generating capability is determined as AIM. Moreover, the major parameters affecting the torque-generating capability, such as magnetic saturation and magnet demagnetization, are examined in depth.

This paper investigates the influence of magnetic saturation on the rotor bar current waveform and performance characteristics of a squirrel-cage Induction Machine (IM). The levels of iron saturation in different parts, including stator and rotor back iron, tooth body and tooth tips etc., are examined and their influences are investigated, while the dominant part which causes the non-sinusoidal rotor bar current waveform is identified. It has revealed that the magnetic saturation, particularly in the rotor tooth, has a significant effect on the bar current waveform and the phenomenon is explained in depth.

The effect of number of rotor slots on the stator and rotor current waveforms, slot and tooth flux densities and performance characteristics, such as torque, torque ripple, losses, electromagnetic force, power factor, and efficiency are numerically studied in case of a 3-phase, 8-pole squirrel-cage induction machine (IM). The IMs have been designed by using the same winding layout, stator outer diameter, stack length, stator current, and rated speed as the Toyota Prius 2010 interior permanent magnet machine. The designed IMs have 48 stator slots and the number of rotor slots is varied from 30 to 76. The geometry parameters of stator and rotor slots are kept at the same in all calculations. The harmonic content of each curve including the force and flux density curves are studied in detail. It has been revealed that the rotor slot number has a significant effect on the distortion level of the bar current and performance characteristics. It has also been shown that there is an optimal rotor slot number at which the maximum available power factor, torque, efficiency and minimum torque ripple are achieved.

This paper investigates the influence of stator slot/pole number combinations on the rotor bar current waveform and electromagnetic performance of a squirrel-cage induction machines (IMs) designed with a slot number per pole per phase of two. 36-slot/6-pole (36S6P), 48S8P, and 60S10P IMs, all having 52 rotor slots, have been designed by using the same winding layout, stator outer diameter, stack length, stator current, and rated speed as the Toyota Prius 2010 interior permanent magnet machine (IPM). The waveforms of flux density in different parts of stator and rotor, and the leakage flux in the slots are considered and their influences are investigated. It has been revealed that even if the winding layout is the same, the stator slot/pole number combination has a considerable effect on the distortion level of the bar current and the electromagnetic performance, including torque, torque ripple, power factor, and efficiency.

Knowledge of the electromagnetic forces at different winding topology provides a good basis for designers and researchers with which to deal with some of the demands that exist for the next generation transformers. Location of the regulating coil in transformer determines to effect of the electrodynamic forces on the operational behavior of the transformer. This paper presents design principles of the regulating coil in transformers and shows the electrodynamics forces by comparing the analytical results with Finite Element Method (FEM) analysis results. In this paper, electrodynamics and leakage field of magnetic force of the 25 MVA power transformers were analyzed under short-circuit condition of the high voltage windings.