共查询到20条相似文献,搜索用时 15 毫秒
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Bo Yin Oruganti R. Panda S.K. Bhat A.K.S. 《Power Electronics, IEEE Transactions on》2009,24(3):620-631
The challenge in controlling a three-phase pulsewidth modulation (PWM) rectifier under balanced conditions arises from the fact that the state-space averaged model reported in literature has a multi-input-multi-output nonlinear structure and furthermore exhibits a nonminimum phase feature. In this paper, a simple single-input-single-output model is constructed by separating the d -axis and the q-axis dynamics through appropriate nonlinear feedforward decoupling while maintaining nearly unity power factor operation. With the proposed model, the nonminimum phase feature inherent in an AC-to-DC rectifier becomes a simple right-half-plane zero appearing in the small-signal control-to-output transfer function. In addition, the model exhibits a close similarity to a DC-DC boost converter under both large-signal and small-signal operating conditions. This makes it possible to extend the system analysis and control design techniques of DC-DC converters to the three-phase PWM rectifier also. The validity of the proposed model has been verified experimentally in the frequency domain under open-loop operation of the PWM rectifier. The usefulness of the model is further demonstrated through closed-loop operation of the rectifier with both voltage mode and inner-current-loop-based schemes. 相似文献
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Huliehel F.A. Wei Tang Lee F.C. Cho B.H. 《Power Electronics, IEEE Transactions on》1995,10(5):597-604
A current-mode control technique, quasi-charge control (QCC), is studied. A small-signal model is developed for QCC. The model is derived for converters operating in the continuous conduction mode. The model is accurate up to half of the switching frequency. The proposed small-signal model is used to assess the dynamics of pulse-width-modulated (PWM) power converters with QCC, and to compare their performance to the current-injected control (CIC) and charge control (CC) schemes. As in CC, the QCC converges to CIC at light loads close to the boundary between continuous and discontinuous conduction modes. The dynamics of power converters with QCC or CC are more sensitive to load change and less sensitive to line change than those of power converters with CIC, especially the current loop dynamics. However, unlike in the case of CC, the dependency on the load/line can be controlled when the QCC is designed. Control design guidelines for DC-DC power converters and power factor correction rectifiers are presented, and experimental measurements are performed to verify the proposed model 相似文献
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A method for systematic synthesis of quasi-resonant (QR) topologies by addition of resonant elements to a parent pulse-width modulation (PWM) converter network is proposed. It is found that there are six QR classes with two resonant elements, including two novel classes. More complex QR converters can be generated by a recursive application of the synthesis method. Topological definitions of all known and novel QR classes follow directly from the synthesis method and topological properties of PWM parents. The synthesis of QR converters is augmented by a study of possible switch realizations and operating modes. In particular, it is demonstrated that a controllable rectifier can be used to accomplish the constant-frequency control in all QR classes. Links between the QR converters and the underlying PWM networks are extended to general DC and small-signal AC models in which the model of the PWM parent is explicitly exposed. Results of steady-state analyses of selected QR classes and operating modes include boundaries of operating regions, DC characteristics, a comparison of switching transitions and switch stresses, and a discussion of relevant design trade-offs 相似文献
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Juinne-Ching Liao Sheng-Nian Yeh 《Power Electronics, IEEE Transactions on》2000,15(6):996-1006
This paper is concerned with the design and implementation of an integrated pulse width modulation (PWM) rectifier/inverter for three-phase induction motor drives. Two identical PWM converters are used to serve as power regulator with unity power factor and servo motor drive using field-oriented control, respectively. A new input-output instantaneous power balancing approach is proposed to improve the dynamic response of input power regulation during output load change in order to minimize the DC-link capacitance. By using the synchronous rotating-frame current regulators, both the input and output currents of the integrated system are characterized with fast current response and low harmonic distortion. The effects of the dynamic response using different input power control methods are compared and the systematic design and analysis of the proposed method are also presented. Theoretical results of the analysis are verified experimentally 相似文献
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Chung-Chieh Fang 《Power Electronics, IEEE Transactions on》2001,16(3):345-350
Sampled-data modeling and analysis are applied to PWM DC-DC converters under one-cycle control or its special case, charge control. These two control schemes are analyzed in a unified framework. Large-signal analysis, steady-state analysis and small-signal analysis are addressed analytically. The orbital nature of the nominal periodic solution is preserved. Various transfer functions are derived. Compared with the averaging approach, the sampled-data approach is more accurate and systematic 相似文献
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Equivalent circuit models for resonant and PWM switches 总被引:4,自引:0,他引:4
The nonlinear switching mechanism in pulsewidth-modulated (PWM) and quasi-resonant converters is that of a three-terminal switching device which consists only of an active and a passive switch. An equivalent circuit model of this switching device describing the perturbations in the average terminal voltages and current is obtained. Through the use of this circuit model the analysis of pulsewidth modulated and quasiresonant converters becomes analogous to transistor circuit analysis where the transistor is replaced by its equivalent circuit model. The conversion ratio characteristics of various resonant converters and their relationship to a single function, called the quasi-resonant function, is easily obtained using the circuit model for the three-terminal switching device. The small-signal response of quasi-resonant converters to perturbations in the switching frequency and input voltage is determined by replacing the three-terminal switching device by its small-signal equivalent circuit model 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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建立了电压型PWM整流器模型,提出一种实用的电流解耦方案,给出一种由dsPIC30F4012型微处理器控制的三相电压型PWM整流器控制系统,详细介绍其系统组成、控制原理及硬件结构,论述其软件流程,给出实验结果. 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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Ning-Yi Dai Man-Chung Wong Yuan-Hua Chen Ying-Duo Han 《Power Electronics Letters, IEEE》2005,3(3):85-88
A three-dimensional (3-D) generalized direct pulse width modulation (PWM) algorithm is proposed for multilevel converters in a three-phase, four-wire system. It is proved to be equivalent to the newly proposed generalized 3-D space vector modulation (SVM). However, the direct PWM greatly simplifies the calculation process and is much easier to implement in digital controllers. The direct PWM can be used in all applications needing a 3-D control vector, such as active filters, uninterruptible power supplies, etc. Simulation and experimental results are given to show the validity of the proposed control strategy. 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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开关电容DC-DC变换器的最佳控制方法 总被引:4,自引:3,他引:1
在采用等效电量关系法对开关电容DC-DC变换器进行分析的基础上,研究了脉冲宽度调制(PWM)和频率调制(FM)的关系.得出开关电容DC-DC变换器的统一等效电路并指出:对开关电容DC-DC变换器,无论采取什么控制方法,都是能耗控制,因此级联低压差线性稳压器是一种最佳的控制方式. 相似文献
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This paper describes the conception and analysis of a unidirectional hybrid three-phase rectifier suitable for medium- and high-power applications. The rectifier is composed of a single-switch diode bridge boost-type rectifier in parallel with a pulsewidth modulation (PWM) three-phase unidirectional boost rectifier. The objective is to obtain a structure capable of providing sinusoidal input currents with low harmonic distortion and dc output voltage regulation. The diode rectifier operates at low frequency and has a higher output power rating. Therefore, the PWM unidirectional rectifier is designed to operate with a small power rating and at a high switching frequency. The total harmonic distortion of the proposed structure varies between 0% and 32%, depending only on the amount of power processed by the PWM three-phase unidirectional rectifier. The rectifier topology conception, principle of operation, control scheme, and simulation and experimental results of a 20-kW laboratory prototype are also presented in this paper. 相似文献
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三电平PWM整流器多采用电压控制外环和电流控制内环组成的双闲环控制系统。电压外环的作用是根据直流电压Udc的大小决定三电平PWM整流器输出功率的大小和方向以及三相电流的给定信号。电流内环的作用是使整流器的实际输入电流能够跟踪电流给定,实现单位功率因数或功率因数可变。文中主要研究了三电平PWM整流器的系统设计,并进行了仿真。结果表明,所设计的双闭环系统具有良好的抗扰动性能,动态响应也得到了明显的改善。 相似文献