scholarly journals Optimization of Air Gap Length and Capacitive Auxiliary Winding in Three-Phase Induction Motors Based on a Genetic Algorithm

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.

2014 ◽  
Vol 651-653 ◽  
pp. 808-811
Author(s):  
Hao Ming Zhang ◽  
Hong Li ◽  
Lian Soon Peh

The present motors are required to high speed, high efficiency, high power density but low pulsating torque. Traditonal rare-earth permanent magnet motor shows its defect; Halbach Array is a new type of permanent magnet structure: magnet field presents unilateral with the sinusoidal distribution. The structure makes the magnetic density of motor’s air gap larger relatively while the magnetic density of rotor’s yoke smaller. And it can help to reduce the motor’s pulsating torque and its size, as well as to raise the power density of motor. The result of finite element analysis based on ANSYS shows that the above structure is able to decrease the mass of motor, to widen the width of air gap and obviously to improve the multi properties of motors.


Author(s):  
Saidah Saidah ◽  
Hari Sutiksno ◽  
Bambang Purwahyudi ◽  
Taufik Taufik

This paper introduces the modelling of a novel three phase AC-AC converter with indirect use of a capacitor as DC voltage link. The proposed converter has high efficiency because it uses Space Vector PWM (SVPWM) technique at both rectificier and inverter stages to operate the pulse width modulation in IGBT switches. The novel converter is equipped with a power factor control to shape the rectifier input current waveform to be sinusoidal and to be in phase with the input voltage. To keep the DC voltage stable, the converter utilizes PI controllers. Simulations are conducted for output voltage from 120 to 300 Volts with output frequency ranging from 30 Hz to 60 Hz. The simulation results show that the converter is able to maintain stable the DC voltage and current. Furthermore, the model demonstrates the benefits of proposed converter in terms of acquiring high input power factor and sinusoidal current waveform at the output side of the inverter.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ying Fan ◽  
Lingling Gu ◽  
Yong Luo ◽  
Xuedong Han ◽  
Ming Cheng

This paper presents a flux-modulated direct drive (FMDD) motor. The key is to integrate the magnetic gear with the PM motor while removing the gear inner-rotor. Hence, the proposed FMDD motor can achieve the low-speed high-torque output and high-speed compact design requirements as well as high-torque density with a simple structure. The output power equation is analytically derived. By using finite element analysis (FEA), the static characteristics of the proposed motor are obtained. Based on these characteristics, the system mathematical model can be established. Hence, the evaluation of system performances is conducted by computer simulation using the Matlab/Simulink. A prototype is designed and built for experimentation. Experimental results are given to verify the theoretical analysis and simulation.


Author(s):  
Maheswari C Krishnakumar ◽  
Rani Thottungal ◽  
Divya A.C

<p>Single Phase Switched Reluctance Motor is more popular in many industrial purposes for high speed applications because of its robust and rugged construction. For low cost and variable speed drive applications SRM are widely used.Due to doubly salient structure of motor, the torque pulsations are high when compared to other sinusoidal machines. The major drawback in using SRM drive is torque pulsations and increased number of switching components. In order to overcome these drawbacks, a bridgeless Single Ended Primary Inductor Converter (SEPIC) is proposed. The major advantages of this converter are continuous output current,smaller voltage ripple and reduced semiconductor current stress when compared to the conventional SEPIC converter. The ripple free input current is obtained by using additional winding of input inductor and auxiliary capacitors. To achieve high efficiency, active power factor correction circuits (PFC) are employed to precise the power factor. Further, the unity power factor can be obtained by making the input current during switching period proportional to the input voltage is proposed. The proposed system consists of reduced components and it is also capable of reducing the conduction losses. The working principles and the waveforms of proposed converter are analyzed. To analyze the circuit operation, theoretical analysis and simulation results are provided. Finally, the  comparison between the waveforms of conventional SEPIC and proposed system is presented by using MATLAB/Simulink tools.</p>


Author(s):  
Tomas A. Gonzalez ◽  
Daniel O. Mercuri ◽  
Hernan E. Tacca ◽  
Maximo E. Pupareli

Modern dc power supplies provide power factor correction but the classical two-stage approach, using hard-switched preregulators, has detrimental effects on efficiency and reliability, particularly for high power applications. With some circuit modifications and the addition of a few magnetic components, diodes and capacitors, we have turned a classical boost power factor corrector into a high efficiency soft-switched version. The proposed converter turns on its single switch with zero current and turns it off with zero voltage. In this paper we explain the proposed changes, we study the waveforms and equations and we verify them with an experimental prototype. We also show how the converter can be used for modular single- and three-phase high power applications.<br /><br />


Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1739
Author(s):  
Syed Sabir Hussain Bukhari ◽  
Ali Asghar Memon ◽  
Sadjad Madanzadeh ◽  
Ghulam Jawad Sirewal ◽  
Jesús Doval-Gandoy ◽  
...  

This paper proposes a novel brushless excitation topology for a three-phase synchronous machine based on a customary current-controlled voltage source inverter (VSI). The inverter employs a simple hysteresis-controller-based current control scheme that enables it to inject a three-phase armature current to the stator winding which contains a dc offset. This dc offset generates an additional air gap magneto-motive force (MMF). On the rotor side, an additional harmonic winding is mounted to harness the harmonic power from the air gap flux. Since a third harmonic flux is generated in this type of topology, the machine structure is also modified to accommodate the third harmonic rotor winding to have a voltage induced as the rotor rotates at synchronous speed. Specifically, four-pole armature and field winding patterns are used, whereas the harmonic winding is configured for a twelve-pole pattern. A diode rectifier is also mounted on the rotor between the harmonic and field windings. Therefore, the generated voltage on the harmonic winding feeds the current to the field winding for excitation. A 2D-finite element analysis (FEA) in JMAG-Designer was carried out for performance evaluation and verification of the topology. The simulation results are consistent with the proposed theory. The topology could reduce the cost and stator winding volume compared to a conventional brushless machine, with good potential for various applications.


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