共查询到20条相似文献,搜索用时 31 毫秒
1.
This paper presents a nine‐switch inverter that can drive two AC motors independently. Recently, as an inverter that can drive them independently, a five‐leg inverter has been proposed. Ten switching devices are used for the five‐leg inverter, whereas only nine are used for the nine‐switch inverter. So, the nine‐switch inverter has the merit that one switching device can be reduced compared to the five‐leg inverter. Moreover, the maximum output voltage of the nine‐switch inverter equals that of the five‐leg inverter. In this work, we propose the structure of the nine‐switch inverter and a modulation method for the same, and validate the nine‐switch inverter by showing simulation results. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
2.
Hombu Mitsuyuki Ueda Shigeta Ueda Akiteru Matsuda Yasuo 《Industry Applications, IEEE Transactions on》1985,(5):1192-1198
A new current source inverter with sinusoidal output voltage and current is presented. Gate turn-off thyristors (GTO's) and pulsewidth modulation (PWM) control techniques are used in the current source inverter to produce the sinusoidal output voltage and current. Three capacitors are connected to the ac output terminals to absorb overvoltages which occur when the GTO current is cut off and to provide a filter function for reducing harmonics in the output current. Voltage spikes, which have been a serious problem in the practical application of this inverter, are suppressed by adding gate pulses which force the inverter into a state of shoot-through. Moreover, this inverter permits the capacitance of an ac output terminal capacitor for absorbing overvoltages to be reduced to one-tenth or less of that of a commutating capacitor in a conventional thyristor type current source inverter. A 3.7-kW induction motor is driven by the inverter. The motor efficiency and noise level are measured and compared with those obtained when the motor is driven by a conventional voltage source PWM inverter. An operating efficiency five or six percent higher and noise level 10 dB lower are obtained for the former. Therefore, this current source GTO inverter is very suitable for ac motor variable speed drives. 相似文献
3.
新型三相混合不对称九电平逆变器研究 总被引:7,自引:2,他引:7
该文提出了一种混合不对称三相九电平逆变器,这种新型的多电平逆变器将不对称五电平逆变器与传统的两电平全桥逆变器级联在一起而获得的。该文对这种逆变器进行了分析,提出了一种新型混合不对称调制方法,并对单相中每个模块的输出电压的频谱和不对称五电平模块的直流母线电容电压不平衡问题进行了分析。文中进行了瞬时反馈数字控制器的设计,最后给出仿真分析和实验验证结果。 相似文献
4.
The operation, analysis, and optimization of a complementary impulse commutated inverter using current impulse instead of voltage impulse for commutation is presented. The operation of the inverter is described, and its salient features are discussed in relation to other commonly used inverters. The trapped energy in the commutation circuit is studied, and methods of feeding back or dissipating this energy are discussed. The optimum operating parameters are derived analytically. This inverter combines the good features of auxiliary commutation with the simplicity of complementary commutation. The advantages of this inverter in pulsewidth modulated (PWNM) inverter applications are examined. A three-phase PWM inverter with a novel switching strategy to minimize losses is designed, tested, and experimental results are presented. 相似文献
5.
6.
A programmed pulsewidth modulation (PWM) technique for selectively eliminating several lower-order harmonics at the output of a neutral point clamped (NPC) inverter topology is investigated. The switching function approach is utilized to derive relevant analytical expressions for input/output variables. A thorough evaluation of the NPC inverter topology based on the switching function approach is described. Optimal power control strategies for an NPC inverter employing programmed PWM patterns are proposed. For a constant-frequency variable-voltage NPC inverter power supply, the proposed strategy is to maintain a minimum specified total harmonic distortion employing a low-output impedance filter. In the case of an NPC inverter powering an AC motor drive, the proposed strategy is to maintain a minimum specified harmonic current factor. The proposed power control strategies are achieved without substantial increase in inverter switching frequency and are therefore suitable for high-power applications employing gate-turn-off-thyristor (GTO) type devices 相似文献
7.
8.
9.
10.
11.
介绍了IGCT的性能特点及使用中应注意的事项,给出了IGCT在两电平逆变器及中点箝位三电平逆变器应用中箝位电路的参数设计方法,分析了IGCT在中点箝位三电平逆变器应用中需要施加外触发的原因,给出了IGCT在6 kV高压变频调速中的应用情况。 相似文献
12.
一种混合级联型多电平逆变器拓扑结构 总被引:6,自引:0,他引:6
在交流电动机调速领域,大容量多电平变换器的应用越来越广泛,为了改善系统性能,各种各样的多电平拓扑结构被提出.本文提出了一种新颖的混合级联式多电平拓扑结构,该结构将传统的H桥逆变器(主逆变器)和二极管钳位型三电平逆变器(从逆变器)结合起来,串联为电动机供电,而这其中仅仅只有主逆变器需要电压源.这种新型的拓扑结构由于增加了从逆变器作为辅助单元用于能量存储,可以提高系统的效率,一定程度上实现电动机的四象限运行.相比传统的H桥逆变器,该拓扑可以减少输入电压源的数目;当电动机以稳定速度运行时,从逆变器可以为负载提供无功能量.该拓扑结构在电力机车和大型舰船推进系统等领域有着广泛的应用前景. 相似文献
13.
常规的Z源逆变器具有任意升降压的功能,同时其所需要的开关器件数量比普通升降压电路少,其单级式结构体积小效率高,而从传统Z源逆变器发展出来的quasi-Z源逆变器,不仅具有所有传统Z源逆变器的优点,同时可以降低器件的应力并减小开关纹波。本文提出的开关电感型quasi-Z源逆变器利用电感和二极管的组合取代了传统quasi-Z源电路中的电感,既保留了传统quasi-Z源电路的优点,同时提高了逆变器的升压倍数和电路的可靠性,而电容电压应力及电感电流应力比开关电感型Z源逆变器低,特别适合于光伏发电等新能源发电领域。通过利用改进的SVPWM控制算法对开关电感型quasi-Z源光伏逆变器进行仿真及实验,验证了该电路及算法的可靠性、稳定性及有效性,适合于光伏发电并网系统。 相似文献
14.
15.
介绍了逆变电路的几种控制方法,通过对电压型逆变电路全桥和半桥结构进行对比,分析了两种逆变电路的原理和特点,为逆变电路的实际应用提供了理论依据。 相似文献
16.
Poh Chiang Loh Feng Gao Blaabjerg F. Shi Yun Charmaine Feng Kong Ngai Jamies Soon 《Industry Applications, IEEE Transactions on》2007,43(5):1295-1308
This paper presents the careful integration of a newly proposed Z-source topological concept to the basic neutral-point-clamped (NPC) inverter topology for designing a three-level inverter with both voltage-buck and voltage-boost capabilities. The designed Z-source NPC inverter uses two unique X-shaped inductance-capacitance (LC) impedance networks that are connected between two isolated dc input power sources and its inverter circuitry for boosting its AC output voltage. Through the design of an appropriate pulsewidth-modulation (PWM) algorithm, the two impedance networks can be short-circuited sequentially (without shooting through the inverter full DC link) for implementing the ldquonearest-three-vectorrdquo modulation principle with minimized harmonic distortion and device commutations per half carrier cycle while performing voltage boosting. With only a slight modification to the inverter PWM algorithm and by short-circuiting the two impedance networks simultaneously, the designed NPC inverter, with no requirement for deadtime delay, can also be operated with a completely eliminated common-mode voltage. Implementation wise, a detailed vectorial analysis interestingly shows that the same generic set of carrier-based modulation expressions can be used for controlling the -source two-level inverter and NPC inverter with and without reduced common-mode switching. All findings presented in this paper have been confirmed in simulation and experimentally using an implemented laboratory prototype. 相似文献
17.
A voltage-source inverter without dc-link components is an ac-to-ac converter having dual bridges of a pulsewidth-modulated (PWM) rectifier and a PWM inverter that can be controlled independently. While conventional matrix converters have disadvantages, such as a complicated commutation scheme and necessity of a large-sized clamp circuit, commutation, and protection of our inverter can be implemented easily. In order to control the PWM rectifier and the PWM inverter independently, snubber circuits for the PWM rectifier are required to assure the path of load current during dead time. In this paper, analytical method of a snubber circuit and operating characteristics of a snubber circuit are described when a 0.75-kW induction motor is driven by our inverter. 相似文献
18.
Hashii Makoto Kousaka Kenji Kaimoto Masahiro 《Industry Applications, IEEE Transactions on》1987,(2):263-269
A control method for GTO PWM inverter parallel-set operation and a new protection system for prevention of short-circuit faults caused by turn-off failure, both to realize a high-power drive system are described. Timing control of GTO gate pulse command provided by a feedback loop, and a reactor at the output of the inverter can minimize the cross current flowing between inverters and can balance the output current of each inverter in inverter parallel-set operation. This method eliminates the necessity of selecting GTO's of equal characteristics, and can apply to parallel-set operation of three or more inverters. The new protection system judges the on and off states of the GTO from the GTO gate-cathode voltage and detects turn-off failure of the GTO. This method positively stops the inverter system safely and reliably upon turn-off failure of the GTO. Experiments are carried out on a 30-kVA inverter and two sets of 450-kVA GTO inverters. 相似文献
19.
20.
This article proposes a novel pulse-width modulation strategy to minimize switching losses of the Z-source inverter. The Z-source inverter has different pulse-width modulation patterns unlike the conventional voltage source inverter. Shoot-through states have been inserted within the zero states of the traditional pulse-width modulation patterns of a voltage source inverter to boost DC input voltage. Thus, the Z-source inverter has six active states, two zero states, and additional shoot-through states differentiating the Z-source and conventional voltage source inverters. The currents flowing through the switches of the Z-source inverter are larger than those of the conventional voltage source inverter, because Z-network currents must flow through the switches during the shoot-through states. Therefore, shoot-through currents increase the total switching losses of the Z-source inverter. In this article, switching losses of the Z-source inverter with the existing pulse-width modulation strategy are analyzed in detail. Then, new modulation signals of the Z-source inverter are introduced to produce unique pulse-width modulation patterns that minimize the switching losses of the Z-source inverter. The switching losses of the Z-source inverter with both pulse-width modulation strategies are simulated and compared. In addition, an experimental system has been built and tested to verify the effectiveness of the proposed strategy. 相似文献