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六相电压源逆变器PWM算法 总被引:1,自引:0,他引:1
针对相移30°双Y联结六相电机,建立了一种基于邻近最大四矢量的六相电压源逆变器空间矢量脉宽调制(SVPWM)算法。根据基波电压调制系数的大小,将调制范围分为正弦调制区和非正弦调制区。在正弦调制区内,逆变器输出正弦相电压;在非正弦调制区内,提出了两种调制策略,通过注入适量的6k±1(k=1,3,5,…)次谐波电压来提高基波电压的幅值。其中的第二种调制算法同时考虑到了参考电压矢量幅值和相角的变化,所以得到了更少的谐波含量。针对算法中PWM波形不对称难以硬件实现的问题,根据电压平均值相等的原则对PWM波形进行了中心化处理,转变成易于硬件实现的形式。实验结果验证了算法的有效性。 相似文献
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Oguchi K. Kawaguchi A. Kubota T. Hoshi N. 《Industry Applications, IEEE Transactions on》1999,35(5):1141-1149
A novel six-phase voltage-fed inverter system is proposed. The system consists of two main three-phase inverters, coupling reactors, and an additional single-phase inverter. The ripple voltage injected into the DC link by the additional inverter results in 60-step load voltages with the help of the coupling reactors. The main inverters operate at the same frequency as the output, and the additional inverter operates at a frequency six times higher. The advantages and disadvantages of the system are quantitatively discussed 相似文献
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The performance of a novel multilevel six-switch (SS) three-phase inverter drive is examined for low-voltage high-speed motor applications. The switching losses of hard-switched voltage-source-inverter topologies place limits on the maximum feasible switching frequency. When operating at higher fundamental frequencies, this results in low-frequency modulation ratios and either high load harmonic currents that cause excessive rotor heating or larger than desired output reactors with a large fundamental voltage drop. The multilevel inverter structure examined offers an increased number of output pulsewidth-modulated (PWM) voltage levels, higher frequency PWM output waveforms, reduced dead-time effects, and a significant reduction in harmonic content. These features reduce the total losses in the motor load when compared to the standard SS three-phase inverter. The harmonic reduction provided by the multilevel topology relative to the standard inverter is experimentally demonstrated with a 15-hp 18 000-r/min induction machine. 相似文献
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Bojoi R. Lazzari M. Profumo F. Tenconi A. 《Industry Applications, IEEE Transactions on》2003,39(3):752-760
A direct rotor-field-oriented control of a dual-three phase induction motor drive is described in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees. The stator windings are fed by a current-controlled pulsewidth-modulation (PWM) six-phase voltage-source inverter. Three key issues are discussed: (1) the machine dynamic model is based on the vector space decomposition theory; (2) the PWM strategy uses the double zero-sequence injection modulation technique which gives good results with low computational and hardware requirements; and (3) to eliminate the inherent asymmetries of the drive power section, a new current control scheme is proposed. Experimental results are presented for a 10-kW dual three-phase induction motor drive prototype. 相似文献
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Farshad Khosravi Amin Mirzaei Mahdi Rezvanyvardom 《International Journal of Circuit Theory and Applications》2019,47(11):1837-1855
This paper proposes a novel cost-effective feature as a three-phase four-switch inverter utilizing a modified quasi Z-source (MQZs) network. This inverter exploits a pulse-width modulation (PWM) control strategy based on developed space vectors to provide balanced three-phase output voltages and currents. It also has many applications such as the three-phase induction motor (IM) with adjustable speed drive (ASD) fed by a DC and/or rectified AC supply. Unlike some other similar four-switch inverters or converters, which can only work in step down (buck) mode or step up (boost) mode, this inverter can operate in both modes that depend on switching signals and due to adjusting the zero shoot-through (Zsh-th) duty cycle. It also decreases the total harmonic distortions (THD) of output voltages and currents. The MQZs inverter reduces the switching losses and the cost of topology in comparison with the conventional six-switch topologies. The utilized control strategy can work well without any extra filtering circuit in DC side to eliminate the effect of the DC-bus voltage ripples on the inverter output currents and voltages. The experimental results are found closely analogous and confirm the aforementioned features of the proposed topology compared with other traditional topologies, although the inverter output filter is a conventional LC filter. 相似文献
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一种新的分相控制式三相电流型五电平逆变器 总被引:1,自引:3,他引:1
在一个三相直接式多电平电流型逆变器(CSI)中利用PWM技术来消除输出电流谐波是非常困难的。文中提出了一类新的三相分相控制式电流型5电平逆变器拓扑。这类拓扑通过三相星形负载的中性线进行解耦,逆变器的每相都可以独立控制,因此可以将多电平PWM技术应用到该类逆变器以减小输出电流谐波。文中给出了一种多载波PWM技术的数字化实现方案。文中以单相逆变器单元为例介绍了三相5电平逆变器的工作原理。最后建立了一个三相分相式5电平CSI的实验系统,验证了文中的结论。随着超导储能系统技术的发展及其应用,电流型多电平变流器将具有广泛的应用前景。 相似文献
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This paper proposes a new PWM rectifier/inverter system that is capable of suppressing not only supply harmonic currents but also electromagnetic interference (EMI). The conversion system consists of a PWM rectifier and inverter, and an active common‐noise canceler (ACC) which has been proposed by the authors. The ACC developed for this system is characterized by the sophisticated connection of a common mode transformer which can compensate for common mode voltages produced by both the PWM rectifier and inverter. As a result, the size of the common mode transformer can be reduced to one‐third, compared with the previously proposed ACC. A prototype PWM rectifier/inverter system (2.2 kW) has been implemented and tested. Some experimental results show reduction characteristics of the supply harmonic current and EMI. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 59–68, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10062 相似文献
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Takayuki Ouchi Hiroyuki Fujikawa Shigeo Masukawa Shoji Iida 《Electrical Engineering in Japan》2001,135(1):43-55
A novel PWM control scheme for a three‐phase current source inverter of a photovoltaic (PV) generation system connected to a utility is proposed. The PV‐array output power can be adjusted by controlling the modulation factor in the proposed PWM pattern. The harmonic components of the output currents can be decreased sufficiently to satisfy the requirements of the Interactive Guidelines. Furthermore, a new Maximum Power Point Tracking control is proposed. The inverter output current should be detected, and the modulation factor may be controlled so as to obtain the maximum effective current. The inverter output power can be maintained at the maximum power point despite fluctuations of panel temperatures, insolation levels, and system voltages. © 2001 Scripta Technica, Electr Eng Jpn, 135(1): 43–55, 2001 相似文献
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斜桥变电所铁磁谐振过电压的仿真研究 总被引:1,自引:0,他引:1
为提高嘉兴电力局配电网面对铁磁谐振过电压的安全性,以斜桥变电所10kV配电网为模型,利用EMTP程序仿真分析了在TV高压侧中性点接非线性电阻、串单相TV(4TV方式)及TV开口三角绕组接阻尼电阻或分频消谐装置等多种消谐措施。结果表明非线性电阻能保持相电压稳定及抑制涌流,正温度系数热敏电阻和3次谐波滤波器可较好解决零序电压的偏高;4TV方式一次侧电流和零序电流过大等问题。还分析了分频消谐装置在实际运行中不能很好消谐的原因。仿真分析结果对提高配电网的供电安全可靠性具有很好的实用价值。 相似文献
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设计了一种新型单相与三相输入兼容的特定消谐式变频器.提出了一种单相与三相输入兼容的变频器主电路,深入研究了离线计算与在线计算相结合实现特定消谐的方法.实验结果表明,该变频器具有消除谐波次数多,残余谐波含量小,电压利用率高,直流母线电压高,输出稳压特性好,开关角数据存储空间小的特点,有很好的应用前景. 相似文献
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This paper proposes space vector pulse width modulation (SVPWM) technique to control a two-phase full bridge voltage source inverter (VSI) having reduced number of static switches with higher phase voltage output. SVPWM gives higher fundamental component amplitude, provides more efficient use of DC supply voltage and generates less harmonic distortion in the output voltages and currents than other pulse width modulation (PWM) techniques. Between asymmetric and symmetric SVPWM only symmetric one is considered so that the harmonic contents are minimized and two different timing sequences and corresponding switching states are proposed. For the implementation three level switching patterns are determined by using software. For real time application these theoretically determined switching signals for the six power transistors are generated by a digital signal processor (DSP) kit and finally the two-phase output voltages are applied to load. The experimental results are found good and in agreement with the theoretical results. Mathematical analysis along with theoretical and experimental performance of the proposed inverter are presented. Total harmonic distortion (THD) and distortion factor (DF) show that the output voltage quality is good enough to apply in any type of practical two-phase load. 相似文献
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高性能五相逆变器PWM算法研究 总被引:1,自引:1,他引:1
多相逆变器的PWM控制技术是船舶电力推进中的关键技术,其性能对推进系统的特性会产生重要的影响.传统的五相电压空间矢量脉宽调制(SVPWM)由相邻的两个大矢量和零矢量合成,只是三相SVPWM控制方法的一种简单应用,逆变器输出目标线电压中含有较大的3次谐波成分.在详细分析五相系统电压空间矢量的基础上,提出了一种低输出谐波和低开关损耗(Less Harmonic Less Loss简称LHLL)的SVPWM法,即LHLLSVPWM控制方法.对提出的控制方法的性能进行了详细的理论分析,并与传统控制方法进行了对比分析,通过实验进行了验证. 相似文献
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为了使电网电压尽可能接近正弦波形,提出了一种通过校正网侧电压波形来减小电网中的谐波电流的智能控制有源滤波技术.智能芯片检测电网电压波形,再与标准正弦电压波形比较求得误差电压,该误差电压中含有电网中谐波电流的波形信息.用这个误差电压形成PWM整流器的指示电流,有源滤波器在智能芯片的控制下从电网吸收谐波电流并向电网输出基波... 相似文献
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基于NPC三电平九相磁通切换永磁电机的控制 总被引:1,自引:0,他引:1
多电平逆变技术是大容量变频调速的首选方案,结合多相电机技术可以进一步提升调速系统的容量。本文对中点钳位(neutral point clamped,NPC)型三电平逆变器供电的10 k W、九相磁通切换永磁(flux-switching permanent magnet,FSPM)电机调速系统进行了仿真和实验研究,探索结合多电平逆变技术和多相电机技术的调速方案。在三相FSPM电机矢量控制的基础上扩展建立了九相FSPM电机的定子磁场定向矢量控制方法,分析了调速系统采用两种载波PWM方式下产生的电压和电流波形。另外,3、5、7次谐波电流的解耦闭环控制成功消除了直流侧中点电位偏移。最后仿真和实验结果证明了理论分析的正确性和有效性。 相似文献
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在转子磁链坐标系下,以电流控制电压源逆变器供电驱动电机运行.通过在电流内环采用高增益控制器,感应电机模型中的2个定子电流分量可近似为定子参考电流,从而可忽略定子电流动态特性的影响,将以定子电压为控制量的感应电机四阶模型降阶成以定子电流为控制量的二阶模型.采用状态反馈线性化方法求得感应电机的逆系统,将多变量、非线性、强耦合的感应电机动态解耦成转速与转子磁链2个一阶子系统.在此基础上,设计一种积分比例(IP)控制器对解耦子系统进行闭环控制.电流内环采用滞环比较器,直接获得PWM信号,控制逆变器实现电流跟踪,从而使调速系统具有快速的动态响应性能.仿真结果验证所提控制方案的有效性和优越性. 相似文献