共查询到19条相似文献,搜索用时 125 毫秒
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传统二极管不控整流或晶闸管相控整流,对电网注入大量谐波及无功功率,造成电源污染.PWM整流器采用全控型开关器件取代二极管或半控型器件,并将PWM控制技术引入整流器,在稳定直流电压输出同时,使交流侧电源电流接近正弦波,实现能量的双向流动.通过介绍单相PWM整流器的控制方法,利用Matlab/Simulink搭建仿真模型,比较分析不同控制方式下PWM整流器运行时电压波形及输入电流的谐波频谱. 相似文献
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通过分析三相电压型PWM整流器的数学模型,建立了PWM整流器在两相旋转坐标系下的数学模型。研究了电压电流双闭环控制策略。基于空间矢量的思想,设计了三相电压型PWM整流器在Matlab/Simulink中的仿真模型。仿真结果表明,此控制方法有效可行。 相似文献
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通过分析三相脉宽调制(PWM)整流器在a-b-c及d-q旋转坐标系下的数学模型,设计了具有前馈解耦控制的PWM整流器双闭环控制系统。根据系统对电流内环及电压外环的控制要求设计了电流比例积分(PI)调节器及电压PI调节器。最后对整个PWM整流器双闭环控制系统进行仿真,并采用以DSP为核心构建PWM整流器控制系统,仿真和实验结果验证了PI调节器设计的正确性。 相似文献
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介绍了单相PWM整流器的工作原理,并在此基础上推导出单相PWM整流器的数学模型。然后通过此数学模型搭建了仿真框架,最后用MA丁LAB/Simulink进行了仿真研究,结果表明瞬时直接电流控制使得单相PWM整流器具备很好的稳态和瞬态性能,实现交流侧功率因数接近于1。 相似文献
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文章对直接电流控制的PWM整流电路开展研究,主要内容如下:(1)设计BOOST型三相桥式PWM整流器的主电路。(2)设计基于直接电流控制的PWM整流电路的控制系统。(3)建立直接电流控制系统Simulink仿真模型,进行仿真分析。仿真结果证明直接电流控制方案使得PWM整流器功率因数接近于1,流入电网的电流基本接近正弦波,对电网的谐波污染小。 相似文献
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A three-phase pulse-width-modulated (PWM) half-controlled rectifier using a novel PWM control strategy whereby the low-order harmonic content in both the input current and the output voltage is reduced is presented. The circuit operates with a unity displacement factor at its input and uses minimum power components. The PWM strategy developed can be implemented on a three-phase half-controlled rectifier bridge with only three controlled switches to obtain PWM controlled rectification. Although the circuit operation is explained with force-commutated SCR switches, the basic controlled PWM operation is valid for any type of switch control. The circuit has wide applications ranging from rectifiers to battery chargers to motor drives. Even if an input current filter is desired, its size will be small due to the PWM pattern used 相似文献
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Techniques for minimizing the input current distortion of current-controlled single-phase boost rectifiers are described. The switching patterns of several boost rectifiers are examined to identify the nature of their input current waveforms. This analysis is used to examine the low-frequency current distortion levels, and hence the power quality, associated with the rectifiers. A PWM (pulse width modulation) strategy that selectively switches between positive unipolar PWM and negative unipolar PWM, called phase-adjusted unipolar PWM, is shown to produce the lowest current distortion levels. A novel two-switch asymmetrical half-bridge rectifier is presented that draws an input current at a unity fundamental power factor and with the same low distortion as obtained with the four-switch H-bridge rectifier. The operation of the various rectifiers is examined with reference to theoretical predictions, circuit simulations, and experimental results. This analysis is used to compare the performances of the various rectifier switching patterns 相似文献
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相对于传统的电压型PWM整流器而言,电流型PWM整流器用于电机驱动具有动态响应快,便于实现再生制动和四象限运行,限流能力强,短路保护可靠性高,能在宽范围内精确控制转矩和速度等优点,在小、中等功率得到广泛的应用。利用三相电压型整流器(VSR)的电压空间矢量调制技术(SVM)实现三相电流型整流器(CSR)的三逻辑空间矢量调制,对其数学模型进行了推导,并利用Matlab建立了系统的仿真模型。仿真结果证明了该方法的有效性,实现了电流型整流器交流侧的单位功率因数和直流侧电流的平稳运行,对电力无功补偿和谐波抑制具有很好的效果。 相似文献
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基于前馈解耦控制策略,研究了三相电压型PWM整流器的建模与控制问题。首先,在d-q旋转坐标系下建立了三相电压型PWM整流器的数学模型,给出了三相电压型PWM整流器的双闭环控制结构,按此方法确定了电压、电流PI调节器的设计方法。仿真结果表明该方法能使所设计的PWM整流器运行于单位功率因数,输出的直流电压稳定在期望值且具有快速的动态响应,满足了设计要求。 相似文献
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Dae-Woong Chung Seung-Ki Sul 《Industrial Electronics, IEEE Transactions on》1999,46(3):517-526
In this paper, the conduction and switching losses of a voltage-fed three-phase pulsewidth modulation (PWM) rectifier are analyzed for various PWM schemes. On the basis of this result, a novel PWM strategy which minimizes the loss of a three-phase PWM rectifier is developed. This minimization result is derived from the following two factors: (1) less switching frequency ratio; and (2) the absence of switching in the vicinity of peak input current. As a result, it is anticipated that the switching loss of the rectifier is reduced by 46%, compared with continuous space-vector PWM rectifiers, and 20% compared with conventional discontinuous space-vector PWM rectifiers. Moreover, the proposed PWM scheme can produce the highest available output voltage because it is based on the concept of the voltage space vector. The effectiveness of the proposed PWM strategy is verified by experiments 相似文献
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基于三相电压型PWM整流器的原理与结构组成,采用电压定向的不定频直接功率控制(VO-DPC),通过对其控制结构的分析,建立其MATLAB/SIMULINK仿真模型.根据仿真结果可以看出,直接功率控制的控制算法简单,而且可以提高整流器的功率因数,有效降低谐波含量. 相似文献
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无论是不控整流电路,还是相控整流电路,功率因数低都是难以克服的缺点.PWM整流电路是采用PWM控制方式和全控型器件组成的整流电路,本文以《电力电子技术》教材为基础,详细分析了单相电压型桥式PWM整流电路的工作原理和四种工作模式.通过对PWM整流电路进行控制,选择适当的工作模式和工作时间间隔,交流侧的电流可以按规定目标变化,使得能量在交流侧和直流侧实现双向流动,且交流侧电流非常接近正弦波,和交流侧电压同相位,可使变流装置获得较高的功率因数. 相似文献