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Tsuneo Kume - One of the best experts on this subject based on the ideXlab platform.
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improvement of output voltage control performance for low speed operation of matrix converter
IEEE Transactions on Power Electronics, 2005Co-Authors: Hidenori Hara, Eiji Yamamoto, Junkoo Kang, Tsuneo KumeAbstract:The matrix converter (MxC) is an ac-to-ac conversion device that can generate variable frequency and variable voltage output. The nine bidirectional switches of an MxC allow pulse-width modulation (PWM) control of input currents and output voltages. PWM switches need "switch Commutations" from one switch to another. During these switch Commutations, however, unwanted voltage error occurs like a dead time effect in a voltage source inverter (VSI). When PWM pulse-widths are narrower than the time for completing a Commutation sequence, voltage error rapidly increases. In the low-speed range, PWM pulses become narrower and voltage distortions become larger due to incomplete Commutations. Moreover, these errors are critical in the low-speed operation because the system is sensitive to the smallest voltage error. In this paper, a new PWM strategy is proposed for improving voltage control performance in the low-speed range. Based on the input and output voltage information, PWM pulse-widths are controlled to avoid incomplete Commutation. The feasibility of the proposed method is proved through simulation and experimental results.
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improvement of output voltage control performance for low speed operation of matrix converter
Power Electronics Specialists Conference, 2004Co-Authors: Hidenori Hara, Eiji Yamamoto, Junkoo Kang, Tsuneo KumeAbstract:The matrix converter (MxC) is an ac-to-ac conversion device that can generate variable frequency, variable voltage output. Nine bidirectional switches of MxC allow PWM control of input currents and output voltages. PWM switching needs "switch Commutations" from one switch to another. During the switch Commutations, however, unwanted voltage error occurs like a dead time effect in voltage source inverter (VSI). When PWM pulse widths are narrower than the time for completing a Commutation sequence, voltage error rapidly increases. In the low speed range, PWM pulses become narrower and voltage distortions become larger due to incomplete Commutations. Moreover these errors are critical in the low speed operation because system is sensitive to even a small voltage error. In this paper, a new PWM strategy is proposed for improving voltage control performance in the low speed range. Based on the input and output voltage information, PWM pulse widths are controlled to avoid incomplete Commutation. The feasibility of the proposed method is proved through simulation and experimental results.
Laurent Aubard - One of the best experts on this subject based on the ideXlab platform.
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Modélisation des Transistors MOS de puissance pour l'électronique de Commutation
1999Co-Authors: Laurent AubardAbstract:Le rendement théorique unitaire des convertisseurs à découpage rend ceux-ci attrayants dès qu'il s'agit de traiter l'énergie électrique. Mais les èontraintes de coût et d'encombrement imposent des fréquences de Commutation toujours plus élevées (ce qui entraîne des contraintes CEM) et l'utilisation de supports modernes permettant la miniaturisation (SMI, Hybride, Silicium). Dans ce contexte, la simulation est devenue une étape indispensable à la conception de convertisseurs et la modélisation fine des éléments qui les constitue (dont les transistors MOS de puissance font souvent partie à faible tension) une nécessité. Ce travail traite de la modélisation du transistor VDMOS et se partage en trois parties. La première aborde le cas de son comportement statique en intégrant la particularité de son canal réalisé par double diffusion. Le modèle simplifié qui en découle se limite à 5 paramètres dont les méthodes d'extraction utilisées sont décrites. La seconde partie de ce travail est une étude fine du comportement dynamique du VDMOS dans sa cellule de Commutation. Elle complète le modèle statique et permet un modèle fiable rendant Gompte de l'influence du niveau de courant sur les Commutations moyelmant 6 paramètres supplémentaires. Les différentes méthodes de mesure pelmettant de déterminer les valeurs de ces paramètres sont détaillées. Enfin, la troisième et dernière partie valide le modèle à l'aide de l'outil de simulation Pspice. Une comparaison est faite avec d'autres modèles proposés dans la littérature.
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Modélisation des Transistors MOS de puissance pour l'électronique de Commutation
1999Co-Authors: Laurent AubardAbstract:Le rendement théorique unitaire des convertisseurs à découpage rend ceux-ci attrayants dès qu'il s'agit de traiter l'énergie électrique. Mais les èontraintes de coût et d'encombrement imposent des fréquences de Commutation toujours plus élevées (ce qui entraîne des contraintes CEM) et l'utilisation de supports modernes permettant la miniaturisation (SMI, Hybride, Silicium). Dans ce contexte, la simulation est devenue une étape indispensable à la conception de convertisseurs et la modélisation fine des éléments qui les constitue (dont les transistors MOS de puissance font souvent partie à faible tension) une nécessité. Ce travail traite de la modélisation du transistor VDMOS et se partage en trois parties. La première aborde le cas de son comportement statique en intégrant la particularité de son canal réalisé par double diffusion. Le modèle simplifié qui en découle se limite à 5 paramètres dont les méthodes d'extraction utilisées sont décrites. La seconde partie de ce travail est une étude fine du comportement dynamique du VDMOS dans sa cellule de Commutation. Elle complète le modèle statique et permet un modèle fiable rendant Gompte de l'influence du niveau de courant sur les Commutations moyelmant 6 paramètres supplémentaires. Les différentes méthodes de mesure pelmettant de déterminer les valeurs de ces paramètres sont détaillées. Enfin, la troisième et dernière partie valide le modèle à l'aide de l'outil de simulation Pspice. Une comparaison est faite avec d'autres modèles proposés dans la littérature.
Hidenori Hara - One of the best experts on this subject based on the ideXlab platform.
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improvement of output voltage control performance for low speed operation of matrix converter
IEEE Transactions on Power Electronics, 2005Co-Authors: Hidenori Hara, Eiji Yamamoto, Junkoo Kang, Tsuneo KumeAbstract:The matrix converter (MxC) is an ac-to-ac conversion device that can generate variable frequency and variable voltage output. The nine bidirectional switches of an MxC allow pulse-width modulation (PWM) control of input currents and output voltages. PWM switches need "switch Commutations" from one switch to another. During these switch Commutations, however, unwanted voltage error occurs like a dead time effect in a voltage source inverter (VSI). When PWM pulse-widths are narrower than the time for completing a Commutation sequence, voltage error rapidly increases. In the low-speed range, PWM pulses become narrower and voltage distortions become larger due to incomplete Commutations. Moreover, these errors are critical in the low-speed operation because the system is sensitive to the smallest voltage error. In this paper, a new PWM strategy is proposed for improving voltage control performance in the low-speed range. Based on the input and output voltage information, PWM pulse-widths are controlled to avoid incomplete Commutation. The feasibility of the proposed method is proved through simulation and experimental results.
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improvement of output voltage control performance for low speed operation of matrix converter
Power Electronics Specialists Conference, 2004Co-Authors: Hidenori Hara, Eiji Yamamoto, Junkoo Kang, Tsuneo KumeAbstract:The matrix converter (MxC) is an ac-to-ac conversion device that can generate variable frequency, variable voltage output. Nine bidirectional switches of MxC allow PWM control of input currents and output voltages. PWM switching needs "switch Commutations" from one switch to another. During the switch Commutations, however, unwanted voltage error occurs like a dead time effect in voltage source inverter (VSI). When PWM pulse widths are narrower than the time for completing a Commutation sequence, voltage error rapidly increases. In the low speed range, PWM pulses become narrower and voltage distortions become larger due to incomplete Commutations. Moreover these errors are critical in the low speed operation because system is sensitive to even a small voltage error. In this paper, a new PWM strategy is proposed for improving voltage control performance in the low speed range. Based on the input and output voltage information, PWM pulse widths are controlled to avoid incomplete Commutation. The feasibility of the proposed method is proved through simulation and experimental results.
He Chao-rong - One of the best experts on this subject based on the ideXlab platform.
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Simulation Analysis on Commutation Failure Criteria for HVDC Transmission Systems
Power system technology, 2007Co-Authors: He Chao-rongAbstract:A detailed electromagnetic transient model for AC/DC hybrid power transmission system of China Southern Power Grid in the year of 2008 is established.By means of the simulation on commutaton failures occurred in converter stations,which belong to four DC transmission lines respectively,i.e.,three DC transmission lines from Guizhou province to Guangdong province and one DC transmission line from Three Gorges power station to Guangdong province,it is found that the Commutation failure will not always occur while the voltage drops to 75% of its rated value.Thus the authors propose a criteria for Commutation failure:the Commutation failure will not always occur while the voltage drops to 70% of its rated value,the crux of the matter depends on that whether the margin angle of valve is smaller than the minimum angle corresponding to the free time of the valve,the voltage of valve is continuously zero and the current of the valve is continuous. When these conditions are ture,the Commutation failure occurs; when these conditiona are false,the Commutation failure will not occur.
H L Hey - One of the best experts on this subject based on the ideXlab platform.
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a true zczvt Commutation cell for pwm converters
IEEE Transactions on Power Electronics, 2000Co-Authors: C M De Oliveira Stein, H L HeyAbstract:This paper introduces a true zero-current and zero-voltage transition (ZCZVT) Commutation cell for DC-DC pulsewidth modulation (PWM) converters operating with an input voltage less than half the output voltage. It provides zero-current switching (ZCS) and zero-voltage switching (ZVS) simultaneously, at both turn on and turn off of the main switch and ZVS for the main diode. The proposed soft-switching technique is suitable for both minority and majority carrier semiconductor devices and can be implemented in several DC-DC PWM converters. The ZCZVT Commutation cell is placed out of the power path, and, therefore, there are no voltage stresses on power semiconductor devices. The Commutation cell consists of a few auxiliary devices, rated at low power, and it is only activated during the main switch Commutations. The ZCZVT Commutation cell, applied to a boost converter, has been analyzed theoretically and verified experimentally. A 1 kW boost converter operating at 40 kHz with an efficiency of 97.9% demonstrates the feasibility of the proposed Commutation cell.