The Experts below are selected from a list of 1587 Experts worldwide ranked by ideXlab platform

Abdallah Saad - One of the best experts on this subject based on the ideXlab platform.

Dan Valentin Nicolae - One of the best experts on this subject based on the ideXlab platform.

  • IECON - Influence of Air-Gap Length on the Performance of a Three-Phase Induction Motor with a Capacitive Auxiliary Stator Winding
    IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society, 2018
    Co-Authors: Mbika Muteba, Dan Valentin Nicolae
    Abstract:

    In order to avoid lower efficiency, poor power factor and lower torque density, the airgap length of a three-phase squirrel cage induction motor (SCIM)should not be designed very large. On other hand, the distortion of airgap flux density distribution can be minimized by enlarging the airgap length. This has informed machine designers to choose very carefully the airgap length while designing a three-phase SCIM. This paper deals with the influence that the airgap length has on the performance of a three-phase SCIM having a capacitive Auxiliary three-phase stator Winding. The three-phase Auxiliary Winding is only magnetically coupled to the stator main Winding. A conventional 5.5 kW, 50-Hz, and 4-pole three-phase SCIM is modified to accommodate both main and Auxiliary Windings in the same stator slots, while maintaining the rated power to 5.5 kW. The results obtained from practical measurements evidenced that for a large airgap it is possible to obtain high efficiency and good power factor with the presence of a capacitive Auxiliary stator Winding. The high efficiency is mainly due the decrease in iron and stator copper losses. The iron losses decrease with increase in airgap length for the SCIM with or without a capacitive Auxiliary Winding, while the stator copper loss is obtained by reactively exciting the three-phase Auxiliary stator Winding.

  • Torque per Ampere Enhancement of a Three-Phase Induction Motor by Means of a Capacitive Auxiliary Winding
    2018 IEEE Transportation Electrification Conference and Expo (ITEC), 2018
    Co-Authors: Mbika Muteba, Dan Valentin Nicolae
    Abstract:

    This paper presents the use of a capacitive three-phase Auxiliary Winding to enhance the torque per ampere of a three-phase Squirrel Cage Induction Motor (SCIM) for electric traction, which generally requires high torque density, a high power factor and high efficiency. The three-phase Auxiliary Winding is only magnetically coupled to the stator's main Winding. A conventional 5.5-kW, 50-Hz, and 4-pole three-phase SCIM is modified to accommodate the main and Auxiliary Windings in the stator slots. The electromagnetic conditions of the machine are studied by means of Finite Element Analysis (FEA). The results obtained from FEA are validated by means of practical results. The results from both FEA and experimental measurements evidence that the torque per ampere is tremendously enhanced when a capacitive excitation is applied to the Auxiliary Winding of the SCIM.

  • Influence of Air-Gap Length on the Performance of a Three-Phase Induction Motor with a Capacitive Auxiliary Stator Winding
    IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society, 2018
    Co-Authors: Mbika Muteba, Dan Valentin Nicolae
    Abstract:

    In order to avoid lower efficiency, poor power factor and lower torque density, the airgap length of a three-phase squirrel cage induction motor (SCIM)should not be designed very large. On other hand, the distortion of airgap flux density distribution can be minimized by enlarging the airgap length. This has informed machine designers to choose very carefully the airgap length while designing a three-phase SCIM. This paper deals with the influence that the airgap length has on the performance of a three-phase SCIM having a capacitive Auxiliary three-phase stator Winding. The three-phase Auxiliary Winding is only magnetically coupled to the stator main Winding. A conventional 5.5 kW, 50-Hz, and 4-pole three-phase SCIM is modified to accommodate both main and Auxiliary Windings in the same stator slots, while maintaining the rated power to 5.5 kW. The results obtained from practical measurements evidenced that for a large airgap it is possible to obtain high efficiency and good power factor with the presence of a capacitive Auxiliary stator Winding. The high efficiency is mainly due the decrease in iron and stator copper losses. The iron losses decrease with increase in airgap length for the SCIM with or without a capacitive Auxiliary Winding, while the stator copper loss is obtained by reactively exciting the three-phase Auxiliary stator Winding.

  • AFRICON - Effect of capacitive Auxiliary Winding on a three-phase induction motor performance behaviour
    2017 IEEE AFRICON, 2017
    Co-Authors: Mbika Muteba, Dan Valentin Nicolae
    Abstract:

    This paper investigates the effect of a capacitive three-phase Auxiliary Winding on the target variables of a three-phase squirrel cage induction motor (SCIM). The three-phase Auxiliary Winding is only magnetically coupled to the stator main Winding. The three-phase SCIM is modelled using 2D Finite Element Method (FEM). The flux density distribution is numerically computed through the magnetostactic solver, and the other target variables of interst such as the efficiency, power factor and torque are obtained through ac magnetic-transient solver. A conventional 4 kW, 50-Hz, and 4-pole three-phase SCIM is modified to accommodate both main and Auxiliary Windings in the stator slots. The results obtained from Finite Element Analysis (FEA) are compared with results from practical measurement (PM). From both simulation and experimental results, it is noted that the capacitive Auxiliary Winding has not only enhanced the power factor, but it also has a significant impact on the efficiency, torque and other electromagnetic parameters of the three-phase SCIM.

  • Effect of capacitive Auxiliary Winding on a three-phase induction motor performance behaviour
    2017 IEEE AFRICON, 2017
    Co-Authors: Mbika Muteba, Dan Valentin Nicolae
    Abstract:

    This paper investigates the effect of a capacitive three-phase Auxiliary Winding on the target variables of a three-phase squirrel cage induction motor (SCIM). The three-phase Auxiliary Winding is only magnetically coupled to the stator main Winding. The three-phase SCIM is modelled using 2D Finite Element Method (FEM). The flux density distribution is numerically computed through the magnetostactic solver, and the other target variables of interst such as the efficiency, power factor and torque are obtained through ac magnetic-transient solver. A conventional 4 kW, 50-Hz, and 4-pole three-phase SCIM is modified to accommodate both main and Auxiliary Windings in the stator slots. The results obtained from Finite Element Analysis (FEA) are compared with results from practical measurement (PM). From both simulation and experimental results, it is noted that the capacitive Auxiliary Winding has not only enhanced the power factor, but it also has a significant impact on the efficiency, torque and other electromagnetic parameters of the three-phase SCIM.

Lamiaâ El Menzhi - One of the best experts on this subject based on the ideXlab platform.

A.a Jimoh - One of the best experts on this subject based on the ideXlab platform.

  • Controlled Capacitance Injection into aThree-Phase Induction Motorthrough aSingle-Phase Auxiliary Stator Winding
    2020
    Co-Authors: A.a Jimoh, V. Nicolae
    Abstract:

    Inthis paper acontrolled static switched capacitor three-phase Auxiliary Winding fedbya three-phase PWM withsingle-phase Auxiliary Winding, whichisonlymagnetically inverter isproposed withsomepositive results. Thissolution coupled tothestator mainWinding, isexplored forimproving the is,however, complexandtherearesomedoubts aboutthe starting andoperating powerfactor ofathree-phase induction controller presented. Othersolution presented in(7, 8)is motor.Theschemeimproves thepowerfactor ofthemotor applicable onlytoa woundrotormachine, astherotoris without compromising significantly on otherperformances. Important advantages of the schemeincludepreventing required tobeconnected toanexternal circuit. harmonics inthelinecurrent, andeliminating regeneration Inthis paperasingle-phase stator Auxiliary Winding thatis possibility aswell aspreventing high inrush currents atstarting. connected toa simple switching schemeisusedtoinject IndexTerms- Three-phase machines, Induction motors,leading reactive powerintoa three-phase squirrel cage Reactive compensation, Powerfactor correction.

  • Analysis of synchronous reluctance machine with magnetically coupled three-phase Windings and reactive power compensation
    IET Electric Power Applications, 2010
    Co-Authors: A.s.o Ogunjuyigbe, A.a Jimoh, D.v Nicolae
    Abstract:

    Synchronous reluctance machine with simple salient rotor is known to have poor power factor because of its poor reactance ratio. This study presents the use of an Auxiliary Winding attached to a balanced capacitor to improve the effective reactance ratio as well as the performance characteristics of synchronous reluctance machine. A unique feature of this configuration is that although the machine runs at synchronous speed, the effective reactance ratio of the machine can be improved by appropriate sizing of the capacitor attached to the Auxiliary Winding, with the constraint of the ampere turn rating of the Auxiliary Winding. The operational characteristics of a simple salient rotor synchronous reluctance machine equipped with this configuration were investigated and shown to have a desirable performance. How the effective reactance ratio, power factor and airgap flux distribution depend on the size of capacitor attached to the Auxiliary Winding is determined using a simplified mathematical model of the system. Analytical results and experimental measurements are in good agreement, and demonstrate the effectiveness and benefits of the configuration.

  • controlled capacitance injection into a three phase induction motor through a single phase Auxiliary stator Winding
    International Electric Machines and Drives Conference, 2007
    Co-Authors: A.a Jimoh, D.v Nicolae
    Abstract:

    In this paper a controlled static switched capacitor with single-phase Auxiliary Winding, which is only magnetically coupled to the stator main Winding, is explored for improving the starting and operating power factor of a three-phase induction motor. The scheme improves the power factor of the motor without compromising significantly on other performances. Important advantages of the scheme include preventing harmonics in the line current, and eliminating regeneration possibility as well as preventing high inrush currents at starting.

  • Improving synchronous reluctance machine performance by direct capacitance injection through an Auxiliary Winding
    2007 International Conference on Electrical Machines and Systems (ICEMS), 2007
    Co-Authors: A.s.o Ogunjuyigbe, A.a Jimoh, D.v Nicolae
    Abstract:

    Synchronous reluctance machine with a conventional rotor structure and a 3-phase Auxiliary Winding attached to a balanced capacitance for power factor improvement will find application in high speed , high power drives. This paper presents an understanding of its operation using the electromagnetic as well as the electric circuit concepts. Analytical and simulation results of this machine configuration show that the torque as well as the power factor performance is better compared to conventional reluctance machine.

  • Performance of an autonomous single-phase induction generator with a bidirectional PWM inverter-battery system in the Auxiliary Winding
    IEEE International Symposium on Industrial Electronics. Proceedings. ISIE'98 (Cat. No.98TH8357), 1998
    Co-Authors: O. Omozusi, A.a Jimoh
    Abstract:

    A stand-alone, single-phase induction generator scheme suitable for producing both controllable load voltage and frequency is set forth. This scheme has a potential utility in industrial and commercial applications. A bi-directional, single-phase PWM inverter-battery system connected to the Auxiliary Winding of the generator supplies the generator reactive power, with the battery either absorbing excess power provided by the turbine or supplying deficit power to meet the active power demand of the load connected to the main Winding. Analytical and computer simulation work are undertaken for a generator feeding an impedance load using two different PWM control schemes. Some of these results are correlated with experimental results, confirming the viability of the generator scheme proposed.

Dylan Dah-chuan Lu - One of the best experts on this subject based on the ideXlab platform.

  • A High-Efficiency AC/DC Converter With Quasi-Active Power Factor Correction
    IEEE Transactions on Power Electronics, 2010
    Co-Authors: Hussain S. Athab, Dylan Dah-chuan Lu
    Abstract:

    This letter presents a novel ac/dc converter based on a quasi-active power factor correction (PFC) scheme. In the proposed circuit, the power factor is improved by using an Auxiliary Winding coupled to the transformer of a cascade dc/dc flyback converter. The Auxiliary Winding is placed between the input rectifier and the low-frequency filter capacitor to serve as a magnetic switch to drive an input inductor. Since the dc/dc converter is operated at high-switching frequency, the Auxiliary Windings produce a high frequency pulsating source such that the input current conduction angle is significantly lengthened and the input current harmonics is reduced. It eliminates the use of active switch and control circuit for PFC, which results in lower cost and higher efficiency. In order to achieve low harmonic content, the input inductor is designed to operate in discontinuous current mode. Operating principles, analysis, and experimental results of the proposed method are presented.

  • A single-switch power-factor-corrected converter with reduced repeated power processing
    4th IEEE International Conference on Power Electronics and Drive Systems. IEEE PEDS 2001 - Indonesia. Proceedings (Cat. No.01TH8594), 2001
    Co-Authors: Dylan Dah-chuan Lu, D.k.w. Cheng
    Abstract:

    By adding an Auxiliary Winding in series with the input boost inductor of a discontinuous conduction mode (DCM) boost/flyback single-switch power-factor-corrected converter (SSPC), the storage capacitor voltage and its range of voltage fluctuation under line variations can be reduced while maintaining high power factor. Furthermore, the flyback transformer provides a direct energy transfer path to output to increase the conversion efficiency of the converter. It is also found that the power factor, the storage capacitor voltage and the conversion efficiency are controlled by the inductance ratio between the input boost inductor, the Auxiliary Winding and the output transformer. This paper presents a detailed analysis of the converter operating in DCM. Experimental results for a 15V/60W prototype with wide input voltage range (90-235V/sub rms/) are given to confirm the theoretical analysis of the converter.