scholarly journals Optimal Design of a Novel Three-Phase High-Speed Flux Reversal Machine

2019 ◽  
Vol 9 (18) ◽  
pp. 3822 ◽  
Author(s):  
Vladimir Prakht ◽  
Vladimir Dmitrievskii ◽  
Vadim Kazakbaev ◽  
Safarbek Oshurbekov ◽  
Mohamed N. Ibrahim

A single-phase flux reversal machine (FRM) has many advantages in high-speed applications because of its simple and reliable rotor structure without magnets or winding, simple and cheap concentrated stator windings, high efficiency, and power density. However, the major problem of single-phase motors is the high torque ripple, which shortens their lifetime and causes noise and vibrations, not only in the machine, but also in the mechanisms coupled therewith. This paper presents a novel three-phase machine consisting of three single-phase machines, having a common shaft aiming to reduce the torque ripple and to improve motor behavior. In this paper, the mathematical model of the single-phase flux reversal motor, as well as the conversion procedure of the single-phase motor parameters to the three-phase ones, is considered. Furthermore, an optimization procedure of the motor and choosing the optimization objectives are done. The finite element two-dimensional (2D) method is used to simulate the machine and to show the results.

2022 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Tianran He ◽  
Ziqiang Zhu ◽  
Fred Eastham ◽  
Yu Wang ◽  
Hong Bin ◽  
...  

This paper overviews high-speed permanent magnet (HSPM) machines, accounting for stator structures, winding configurations, rotor constructions, and parasitic effects. Firstly, single-phase and three-phase PM machines are introduced for high-speed applications. Secondly, for three-phase HSPM machines, applications, advantages, and disadvantages of slotted/slotless stator structures, non-overlapping/overlapping winding configurations, different rotor constructions, i.e., interior PM (IPM), surface-mounted PM (SPM), and solid PM, are summarised in detail. Thirdly, parasitic effects due to high-speed operation are presented, including various loss components, rotor dynamic and vibration, and thermal aspects. Overall, three-phase PM machines have no self-starting issues, and exhibit high power density, high efficiency, high critical speed, together with low vibration and noise, which make them a preferred choice for high-performance, high-speed applications.


2020 ◽  
Vol 10 (17) ◽  
pp. 6024
Author(s):  
Vladimir Dmitrievskii ◽  
Vladimir Prakht ◽  
Vadim Kazakbaev ◽  
Dmitry Golovanov

Single-phase motors are used in low-power, cost-effective, variable-speed applications. As a replacement to traditional single-phase synchronous motors with magnets on the rotor, single-phase flux reversal motors (FRMs) with a rugged and reliable toothed rotor are considered for the high-speed applications. However, torque pulsations of single-phase motors are high. The aim of this work is to minimize the torque ripple and increase its minimum instantaneous value, as well as to reduce FRM losses. To solve this problem, an asymmetric rotor is used, and an objective function is proposed, which includes parameters characterizing the pulsations of the torque and the loss of FRM for two load conditions. To optimize the single-phase FRM and minimize the objective function, the Nelder–Mead method was applied. The optimization criterion was selected to maximize the efficiency, to reduce the torque ripple, and to the avoid the negative torque in a wide range of powers at the fan load (quadric dependence of torque on speed). Two operating loading modes are considered. After two stages of optimization, the peak-to-peak torque ripple in the FRM in the rated loading mode decreased by 1.7 times, and in the mode with reduced load by 2.7 times. In addition, in the FRM before optimization, the torque has sections with negative values, and in the FRM after optimization, the torque is positive over the entire period. Although losses in the rated mode increased by 4%, when underloaded, they decreased by 11%, which creates an additional advantage for applications that work most of the time with underload.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4407
Author(s):  
Mbika Muteba

There is a necessity to design a three-phase squirrel cage induction motor (SCIM) for high-speed applications with a larger air gap length in order to limit the distortion of air gap flux density, the thermal expansion of stator and rotor teeth, centrifugal forces, and the magnetic pull. To that effect, a larger air gap length lowers the power factor, efficiency, and torque density of a three-phase SCIM. This should inform motor design engineers to take special care during the design process of a three-phase SCIM by selecting an air gap length that will provide optimal performance. This paper presents an approach that would assist with the selection of an optimal air gap length (OAL) and optimal capacitive auxiliary stator winding (OCASW) configuration for a high torque per ampere (TPA) three-phase SCIM. A genetic algorithm (GA) assisted by finite element analysis (FEA) is used in the design process to determine the OAL and OCASW required to obtain a high torque per ampere without compromising the merit of achieving an excellent power factor and high efficiency for a three-phase SCIM. The performance of the optimized three-phase SCIM is compared to unoptimized machines. The results obtained from FEA are validated through experimental measurements. Owing to the penalty functions related to the value of objective and constraint functions introduced in the genetic algorithm model, both the FEA and experimental results provide evidence that an enhanced torque per ampere three-phase SCIM can be realized for a large OAL and OCASW with high efficiency and an excellent power factor in different working conditions.


2021 ◽  
Vol 297 ◽  
pp. 01017
Author(s):  
Fouad Labchir ◽  
Mhammed Hasoun ◽  
Aziz El Afia ◽  
Karim Benkirane ◽  
Mohamed Khafallah

In this paper a direct torque control strategy for dual three-phase permanent magnet synchronous motor (DTP-PMSM) is presented, the machine has two sets of three-phase stator windings spatially phase shifted by 30 electric degrees. In order to reduce the stator harmonic current, torque and flux are controlled based on regulators and Vector Space Decomposition technique. The proposed approach has the benefits of low stator current distortion and low torque ripple. The validity and the efficiency of the selected technique are confirmed by simulation results.


Author(s):  
Uldis Antonovičs ◽  
Viesturs Bražis ◽  
Jānis Greivulis

The Mechanical Transient Process at Asynchronous Motor Oscillating ModeThe research object is squirrel-cage asynchronous motor connected to single-phase sinusoidal. There are shown, that by connecting to the stator windings a certain sequence of half-period positive and negative voltage, a motor rotor is rotated, but three times slower than in the three-phase mode. Changing the connecting sequence of positive and negative half-period voltage to stator windings, motor can work in various oscillating modes. It is tested experimentally. The mechanical transient processes had been researched in rotation and oscillating modes.


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