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Wei Hua - One of the best experts on this subject based on the ideXlab platform.
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Analytical Approach for Cogging Torque Reduction in Flux-Switching Permanent Magnet Machines Based on Magnetomotive Force-Permeance Model
IEEE Transactions on Industrial Electronics, 2018Co-Authors: Xiaofeng Zhu, Wei Hua, Wentao Huang, Hengliang Zhang, Ming ChengAbstract:Flux-switching permanent magnet machine typically suffers from relatively high cogging torque due to its special doubly salient structure and high air-gap flux density, causing undesired torque ripples, as well as acoustic noise and vibration, especially at low speeds. In this paper, an analytical expression of cogging torque is derived based on a Magnetomotive Force-permeance model, through which the optimal design parameters and dimensions, such as combinations of stator slots and rotor poles, skewing angle, stator tooth width, rotor tooth width, and magnet thickness, can be determined. Based on the derived analytical model, two novel approaches for cogging torque reduction are proposed, i.e., asymmetric Magnetomotive Force and asymmetric permeance, respectively, and consequently, the optimal designs are also acquired analytically. However, it is also found that the optimal choice of the proposed techniques depends on the combinations of stator slots and rotor poles of the machines. Finally, the effectiveness of the proposed approaches is verified by both finite element analytical predictions and experimental results.
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General Airgap Field Modulation Theory for Electrical Machines
IEEE Transactions on Industrial Electronics, 2017Co-Authors: Ming Cheng, Peng Han, Wei HuaAbstract:This paper proposes a general field modulation theory for electrical machines by introducing Magnetomotive Force modulation operator to characterize the influence of short-circuited coil, variable reluctance, and flux guide on the primitive magnetizing Magnetomotive Force distribution established by field winding function multiplied by field current along the airgap peripheral. Magnetically anisotropic stator and rotor behave like modulators to produce a spectrum of field harmonics and the armature winding plays the role of a spatial filter to extract effective field harmonics to contribute the corresponding flux linkage and induce the electromotive Force. The developed field modulation theory not only unifies the principle analysis of a large variety of electrical machines, including conventional dc machine, induction machine, and synchronous machine which are just special cases of the general field modulated machines, thus eliminating the problem of the machine theory fragmentation, but also provides a powerful guidance for inventing new machine topologies.
Ming Cheng - One of the best experts on this subject based on the ideXlab platform.
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Analytical Approach for Cogging Torque Reduction in Flux-Switching Permanent Magnet Machines Based on Magnetomotive Force-Permeance Model
IEEE Transactions on Industrial Electronics, 2018Co-Authors: Xiaofeng Zhu, Wei Hua, Wentao Huang, Hengliang Zhang, Ming ChengAbstract:Flux-switching permanent magnet machine typically suffers from relatively high cogging torque due to its special doubly salient structure and high air-gap flux density, causing undesired torque ripples, as well as acoustic noise and vibration, especially at low speeds. In this paper, an analytical expression of cogging torque is derived based on a Magnetomotive Force-permeance model, through which the optimal design parameters and dimensions, such as combinations of stator slots and rotor poles, skewing angle, stator tooth width, rotor tooth width, and magnet thickness, can be determined. Based on the derived analytical model, two novel approaches for cogging torque reduction are proposed, i.e., asymmetric Magnetomotive Force and asymmetric permeance, respectively, and consequently, the optimal designs are also acquired analytically. However, it is also found that the optimal choice of the proposed techniques depends on the combinations of stator slots and rotor poles of the machines. Finally, the effectiveness of the proposed approaches is verified by both finite element analytical predictions and experimental results.
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General Airgap Field Modulation Theory for Electrical Machines
IEEE Transactions on Industrial Electronics, 2017Co-Authors: Ming Cheng, Peng Han, Wei HuaAbstract:This paper proposes a general field modulation theory for electrical machines by introducing Magnetomotive Force modulation operator to characterize the influence of short-circuited coil, variable reluctance, and flux guide on the primitive magnetizing Magnetomotive Force distribution established by field winding function multiplied by field current along the airgap peripheral. Magnetically anisotropic stator and rotor behave like modulators to produce a spectrum of field harmonics and the armature winding plays the role of a spatial filter to extract effective field harmonics to contribute the corresponding flux linkage and induce the electromotive Force. The developed field modulation theory not only unifies the principle analysis of a large variety of electrical machines, including conventional dc machine, induction machine, and synchronous machine which are just special cases of the general field modulated machines, thus eliminating the problem of the machine theory fragmentation, but also provides a powerful guidance for inventing new machine topologies.
Bukšnaitis Jonas - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Magnetomotive Force of single-phase and three-phase windings of rotating electric machines
2020Co-Authors: Bukšnaitis Jonas, Gečys SteponasAbstract:Analysis of Magnetomotive Force of concentrated and distributed single-phase and three-phase windings was performed using momentary graphical images of Magnetomotive Force functions of considered windings, which vary in time and in space, which are formed at most acceptable moment of time, when maximal current flows in single-phase windings, and phase U current in three-phase windings equals zero. These images, as periodical functions, are described by Fourier sequences. General analytical expressions of pulsating and rotating magnetic fields were received, which can be applied when investigating Magnetomotive Force created by single-phase and three-phase windingsVytauto Didžiojo universitetasŽemės ūkio akademij
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Research of Electromagnetic Parameters of Single-layer Three-phase and Six-phase Chain Windings
2020Co-Authors: Bukšnaitis JonasAbstract:The research of electromagnetic parameters of single-layer three-phase and six-phase chain windings was accomplished. It was determined that the instantaneous space distributions of rotating Magnetomotive Force in the three-phase chain winding are asymmetrical in respect of coordinate axes and symmetrical in respect of the origin of these axes. Instantaneous space distributions of rotating Magnetomotive Force generated by six-phase chain winding, contrary to the three-phase windings, are symmetrical in respect of coordinate axes. After accomplishing harmonic analysis of spatial rotating Magnetomotive Forces, it was obtained, that odd and even harmonics exist in the harmonic Magnetomotive Force spectrum generated by three-phase winding, and only odd harmonics in the spectrum generated by six-phase winding. The electromag-netic efficiency factors were calculated for both types of windings, and it was determined that for six-phase winding this factor is 23,7 % higher compared to three-phase winding. Furthermore, it was estimated, that the conditional amplitude of fundamental Magnetomotive Force harmonic in the analyzed six-phase winding is 2,13 times larger compared to the same amplitude value in the analogous three-phase windingVytauto Didžiojo universitetasŽemės ūkio akademij
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Sinusinių trifazių apvijų elektromagnetinių parametrų tyrimas
2020Co-Authors: Bukšnaitis JonasAbstract:Nagrinėjamas didžiausio ir sutrumpinto vidutinio žingsnio sinusinių trifazių apvijų, kurių gali būti optimizuojamos pulsuojamosios arba sukamosios magnetovaros, vijų paskirstymas sekcijoms jų grupėse. Gautos analizinės išraiškos visų keturių šių apvijų tipų vijų skaičiui sekcijose nustatyti. Pagal šias išraiškas Šių išraiškų pagrindu apskaičiuoti sekcijų, sudarančių sekcijų grupę nuo dviejų iki keturių sekcijų, vijų skaičiai santykiniais dydžiais, susieti su sutelktąja trifaze apvija. Sudaryta nagrinėjamųjų sinusinių trifazių apvijų magnetovaros pokyčių grioveliuose santykiniais dydžiais laiko momentu t=0 lentelė ir pagal jos duomenis gautos akimirkinės sukamosios magnetovaros erdvinės laiptinės funkcijos. Iš šių sukamosios magnetovaros grafinių vaizdų nustatyti realūs ir sąlyginiai pakopų formos pusperiodžių parametrai, kurių pagrindu analiziškai apskaičiuotos erdvinių harmonikų sukamosios magnetovaros sąlyginės amplitudinės vertės. Pagal šių sąlyginių amplitudinių verčių duomenis surasti sukamųjų magnetovarų erdvinių harmonikų santykiniai dydžiai ir jais remiantis apskaičiuoti nagrinėjamųjų sinusinių trifazių apvijų magnetovaros iškreipiu ir elektromagnetinio efektyvumo koeficientai. Pagal gautą išraišką taip pat nustatyti šioms apvijoms pagrindinės ir aukštesniųjų harmonikų apvijos koeficientai. Remiantis gautais sinusinių trifazių apvijų elektromagnetinių parametrų tyrimo rezultatais, padarytos išvadosThe distribution of the turns within section groups of the sinusoidal three-phase windings with maximum and average short-pisch are analyzed, for which pulsating or rotational Magnetomotive Forces can be optimized. Analytical expressions for evaluation of number of turns in the sections of windings of all four types were derived. On the basis of these expressions, there were calculated numbersof turns in relative quantities for sections, which form groups from two to four sections. These relative quantities are related to concentrated three-phase winding. Data table of Magnetomotive Force changes in the slots of considered sinusoidal three-phase windings in the moments of time t = Q was formed and momentary dimensional stair-shape functions of rotational Magnetomotive Force were obtained according to this data. Real and conditional parameters of stair-shape half-periods were determined from the graphical representations of rotational Magnetomotive Force. On their basis the conditional amplitude values of dimensional harmonics of rotational magntomotive Force were found, which were used to evaluate analytically the conditional amplitude values of dimensional harmonics of rotating Magnetomotive Force. According to the data of conditional amplitude values the relative quantities of rotational Magnetomotive Force dimensional harmonics were found, which were later used to calculate Magnetomotive Force distortion and electromagnetic effiaenc factors of considered three-phase windings. Winding factors of fundamental and higher harmonics were also determined according to the derived expression. Conclusions are offered on the basis of research of electromagnetic parameters of sinusoidal three-phase windingsVytauto Didžiojo universitetasŽemės ūkio akademij
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Electromagnetic investigation of multi-phase windings of alternating current machines
2020Co-Authors: Bukšnaitis Jonas, Kulikauskas TadasAbstract:The research electromagnetic efficiency of a concentrated six-phase winding has been accomplished. The phase change sequence of sixphase winding was determined at first, and the electric circuit layout of the analyzed winding was created on the base of theory of three-phase windings. Instantaneous space functions of rotating Magnetomotive Force were created using developed layout and instantaneous values of phase currents at time moments t = 0 and t = T / 12 with aim to determine the harmonic spectrum of rotating Magnetomotive Force induced by six-phase winding. Harmonic analysis of these functions was accomplished and the electromagnetic efficiency factor of the considered six-phase winding was calculated on the basis of obtained results. Calculated factor was compared with electromagnetic efficiency factor of concentrated three-phase winding, and it was determined that it was 20,0% higher compared to the latter. Additionally, it was determined that the amplitude value of rotating Magnetomotive Force fundamental harmonic of analyzed six-phase winding was 1.983 higher than the same amplitude value of analogous three-phase winding. This means that the energy factors of alternating current electrical motor designed and manufactured using concentrated six-phase winding would be considerably higher compared to motor with concentrated three-phase windingVytauto Didžiojo universitetasŽemės ūkio akademij
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Šešiafazės apvijos elektromagnetinis efektyvumas
'Kaunas University of Technology (KTU)', 2020Co-Authors: Bukšnaitis JonasAbstract:Atliktas dvisluoksnės forminės šešiafazės apvijos elektromagnetinio efektyvumo tyrimas. Pirmiausia nustatyta šešiafazių apvijų fazių kaita ir, remiantis trifazių apvijų teorija, sudaryta nagrinėjamos apvijos elektrinės schemos išklotinė. Šešiafazės apvijos kuriamos sukamosios magnetovaros harmoniniam spektrui nustatyti, pasinaudojus sudaryta schema ir fazinių srovių laiko momentu t = 0 akimirkinėmis vertėmis, sudaryta sukamosios magnetovaros akimirkinė erdvinė funkcija. Atlikta šios funkcijos harmoninė analizė ir pagal jos rezultatus apskaičiuotas nagrinėjamos šešiafazės apvijos elektromagnetinio efektyvumo koeficientas. Gautas koeficientas palygintas su analogiškų parametrų dvisluoksnės forminės trifazės apvijos elektromagnetinio efektyvumo koeficientu ir nustatyta, kad jis 8,64 % didesnis už pastarąjį. Be to, gauta, kad išnagrinėtos šešiafazės apvijos pagrindinės magnetovaros harmonikos amplitudinė vertė 1,983 karto didesnė už analogiškos trifazės apvijos šią amplitudinę vertę. Tai reiškia, kad kintamosios srovės elektros mašinų su šešiafazėmis apvijomis energiniai rodikliai turėtų būti pastebimai didesni nei trifazių mašinų. II. 2, bibl. 8, lent. 5 (anglų kalba; santraukos anglų ir lietuvių k.)The investigation of electromagnetical efficiency of the two-layer preformed six-phase winding is presented. At first the variation of phases of the six-phase windings was determined and, on the basis of the theory of three-phase windings, the development of the electrical circuit of the analyzed winding was formed. In order to determine the harmonic spectrum of rotating Magnetomotive Force created by the six-phase winding the instantaneous space function of rotating Magnetomotive Force was formed by using the created circuit and instantaneous values of the phase currents in the moment of time t = 0. The harmonic analysis of this function was performed and according to its results the electromagnetical efficiency factor of the analyzed six-phase winding was calculated. The obtained factor was compared to the electromagnetical efficiency factor of the two-layer preformed three-phase winding of analogous parameters and it was determined that it is 8,64 % higher than in the three-phase winding case. Additionally it was obtained that the amplitude value of the fundamental harmonic of rotating Magnetomotive Force of the analyzed six-phase winding is 1,983 times higher that the amplitude value of rotating Magnetomotive Force of the analogous three-phase winding. This means that the power factors of the alternating current electrical machines with the six-phase windings should be notably higher compared to the three-phase machines. 111. 2, bibl. 8, tabl. 5 (in English; abstracts in English and Lithuanian)Vytauto Didžiojo universitetasŽemės ūkio akademij
Zhao Yao - One of the best experts on this subject based on the ideXlab platform.
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position sensorless starting method of bldc motor based on svpwm and stator Magnetomotive Force control
Conference of the Industrial Electronics Society, 2013Co-Authors: Ma Xiaohan, Wang Xiaolin, Deng Zhiquan, Zhou Pengfei, Zhao YaoAbstract:In open-loop starting process of Brushless DC motor without position sensors, pulsations of torque and speed are large and motor cannot even start successfully. In order to solve those problems, Space Vector Pulse Width Modulation control schema of three-phase inverter employing 180° switch-on mode is analyzed. Moreover, relationship between the composed stator Magnetomotive Force and current maximum phase's Magnetomotive Force is derived with windings in Y connection. Hence, this paper proposes a new starting control strategy combing stator Magnetomotive Force regulation with SVPWM. Furthermore, calculation of the composed stator Magnetomotive Force is simplified. The proposed starting algorithm is independent of saliency or initial position of rotor. It can also effectively suppress ripples of speed and torque, so its starting performance is greatly improved compared with conventional variable-frequency open-loop start. Finally, validity of the presented algorithm is verified by simulation and experiment.
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IECON - Position sensorless starting method of BLDC motor based on SVPWM and stator Magnetomotive Force control
IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society, 2013Co-Authors: Ma Xiaohan, Wang Xiaolin, Deng Zhiquan, Zhou Pengfei, Zhao YaoAbstract:In open-loop starting process of Brushless DC motor without position sensors, pulsations of torque and speed are large and motor cannot even start successfully. In order to solve those problems, Space Vector Pulse Width Modulation control schema of three-phase inverter employing 180° switch-on mode is analyzed. Moreover, relationship between the composed stator Magnetomotive Force and current maximum phase's Magnetomotive Force is derived with windings in Y connection. Hence, this paper proposes a new starting control strategy combing stator Magnetomotive Force regulation with SVPWM. Furthermore, calculation of the composed stator Magnetomotive Force is simplified. The proposed starting algorithm is independent of saliency or initial position of rotor. It can also effectively suppress ripples of speed and torque, so its starting performance is greatly improved compared with conventional variable-frequency open-loop start. Finally, validity of the presented algorithm is verified by simulation and experiment.
Hisao Kubota - One of the best experts on this subject based on the ideXlab platform.
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study of the magnetization method suitable for fractional slot concentrated winding variable Magnetomotive Force memory motor
IEEE Transactions on Power Electronics, 2014Co-Authors: Sari Maekawa, Kazuaki Yuki, Makoto Matsushita, Isamu Nitta, Yukihisa Hasegawa, Tsuyoshi Shiga, Tsuyoshi Hosoito, Kazunobu Nagai, Hisao KubotaAbstract:This paper describes a variable Magnetomotive-Force memory motor with a fractional-slot concentrated winding. We propose a method for optimal control of magnetization suitable for a fractional-slot concentrated winding. Our result shows that variable magnetized magnets are more highly magnetized when a fractional-slot concentrated winding is used than those using the conventional method.