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开关电容变换器研究主要集中在对单桥臂试验波形、效率和等效电阻的分析。随着交流场合应用需求的增加,双桥臂ACAC开关电容变换器逐渐发展。由于双桥臂的电路结构、工作过程较复杂,目前对其暂态工作过程的研究甚少。为了提升电路性能,对AC-AC开关电容变换器在低频、高频的工作过程和换向过程进行了深入研究。给出了该变换器的控制驱动方式,并对高频工作过程进行了理论分析。最后通过仿真对该变换器进行了验证。该变换器各功率开关管以及电容的电压应力研究,对于开关电容变换器在双桥臂领域的电路参数选择具有重要的参考价值。开关电容变换器的工作过程和换向规律,为双桥臂开关电容变换器的进一步研究奠定了基础。 相似文献
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为了解决Boost变换器在极限占空比情况下才能获得高电压增益这一缺点,在传统的Sepic变换器基础上提出一种新型的高增益变换器。该变换器保留了Sepic变换器输入电流连续等优点,通过引入无源钳位电路,降低了开关管的电压应力,同时由于耦合电感的漏感与电容发生谐振,有效减弱了二极管反向恢复问题的影响。详细分析了变换器在每个开关模态的工作过程,推导出变换器的电压增益表达式和开关器件的电压应力。制作一台100 W的实验样机,通过实验验证了理论分析的正确性。 相似文献
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摘要:开关电容变换器一直是一个重要的研究领域。近年来,随着交流场合应用的需要,AC-AC开关电容变换器在逐渐发展,主要集中在单桥臂的研究,对于双桥臂的研究较少,尤其在高频工作过程方面还有待发展。通过对各种直流、单相交流开关电容变换器的研究,发现所研究的开关电容变换器主要集中在对单桥臂实验波形、效率和等效电阻的分析,由于双桥臂的电路结构、工作过程比单桥臂要复杂,对其暂态工作过程的研究很少,而开关电容变换器的工作过程和等效电阻的研究对设计双桥臂开关电容变换器以及提高电路的稳态特性有着重要作用。为了更好的提升电路的性能和稳态特性,对1-2升压型双桥臂开关电容变换器在低频、高频的工作过程和换向过程进行了深入研究,给出了开关电容变换器的控制驱动方式,并通过高频分析进行暂态建模得到了等效内阻的表达式。最后通过仿真对分析结果进行了验证。 相似文献
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摘要:开关电容变换器一直是一个重要的研究领域。近年来,随着交流场合应用的需要,AC-AC开关电容变换器在逐渐发展,主要集中在单桥臂的研究,对于双桥臂的研究较少,尤其在高频工作过程方面还有待发展。通过对各种直流、单相交流开关电容变换器的研究,发现所研究的开关电容变换器主要集中在单桥臂实验波形、效率和等效电阻的分析,由于双桥臂的电路结构、工作过程比单桥臂要复杂,对其暂态工作过程的研究很少,而开关电容变换器的工作过程和等效电阻的研究对设计双桥臂开关电容变换器以及提高电路的稳态特性有着重要作用。为了更好的提升电路的性能和稳态特性,对1-2型双桥臂开关电容变换器在低频、高频的工作过程和换向过程进行了深入研究,给出了开关电容变换器的控制驱动方式,并通过高频分析进行暂态建模得到了等效内阻的表达式。最后通过仿真对分析结果进行了验证。 相似文献
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准谐振变换器可以实现功率器件的零电压或零电流开关,但要得到稳定输出电压需采用脉冲频率调制(PFM),这给功率电路参数设计和系统稳定性带来困难,本文研究一种PFM结合PWM的控制模式来调节准谐振变换器输出电压,并实现其开关管的软开关,该控制方案与电压调节器协调工作,调节功率管驱动信号的脉宽和频率,保证了软开关条件和降低导通损耗,实现高频高效的功率变换。建立了100W升压准谐振变换器样机,实验结果验证了该控制方案的可行性。 相似文献
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Antônio de Pádua Finazzi Gustavo Brito de Lima Luiz Carlos de Freitas Ernane A.A. Coelho Valdeir José Farias Luiz C.G. Freitas 《Microprocessors and Microsystems》2014
The development of front-end converters for power factor correction and DC link voltage control of power electronics converters such as, UPS, Inverters, and Switched Power Supplies, has been attracting great interest from the scientific community that works toward the achievements of cost reduction, high efficiency, and reliability. In this context, this paper proposes a microprocessed control technique for sinusoidal input line current imposition in front-end ac–dc converters. This gave rise to an innovative sensorless boost converter, named in this work as PFC-Boost-CSL. The proposed method is based on experimental acquisition of gate-drive signal sequences for different load conditions. These signals correspond to a complete cycle of the AC input voltage and are recorded in the microcontroller memory in order to be reproduced when used in a boost converter without current sensor. In the operation of PFC-Boost-CSL, a suitable switching sequence is sent to drive the power switch in order to minimize output voltage error and maintain a sinusoidal input current. Aiming to prove the proposed control concept, a 600 W PFC-Boost-CSL prototype was built and analyzed in laboratory and the main experimental results are presented herein. 相似文献
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Decentralized output voltage tracking of cascaded DC–DC converters is an interesting topic to obtain a high voltage conversion ratio. The control purpose is challenging due to the load resistance changes, renewable energy supply voltage variations and interaction of the individual converters. In this paper, four novel decentralized adaptive neural network controllers are designed on the cascaded DC–DC buck and boost converters under load and DC supply voltage uncertainties. In the beginning, individual buck and boost converter average models that can operate in both continuous and discontinuous conduction modes are derived. Then, the interconnected and decentralized state-space models of cascaded buck and boost converters are extracted. These models are highly nonlinear with unknown uncertainties which can be estimated by neural networks. Further, two decentralized adaptive backstepping neural network voltage controllers are proposed on cascaded buck converters to deal with uncertainties and interactions. However, these control strategies are not applicable to a boost converter due to its non-minimum phase nature. Then, two novel decentralized adaptive neural network with a conventional proportional–integral reference current generator are developed on the cascaded boost converters. Practical stability of the overall system is guaranteed for the proposed controllers using Lyapunov stability theorem. Finally, four control strategies provide good quality of output voltage in the presence of uncertainties and interactions. Comparative simulations are carried out on cascaded buck and boost converters to validate the effectiveness and performance of the designed methods. 相似文献
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DC–DC power converters are switched devices whose averaged dynamics are described by a bilinear second-order system with saturated input. In some cases (e.g., boost and buck–boost converters), the input output dynamics can be of nonminimum-phase nature. Current-mode control is the standard strategy for output voltage regulation in high dynamic performance industrial DC–DC power converters. It is basically composed by a saturated linear state feedback (inductor current and output voltage) plus an output voltage integral feedback to remove steady-state offset. Despite its widespread usage, there is a lack of rigorous results to back up its stabilization capability and to systematize its design. In this paper, we prove that current-mode control yields semiglobal stability with asymptotic regulation of the output voltage. 相似文献
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提高矩阵变换器电压传输比的新型调制策略 总被引:2,自引:0,他引:2
电压传输比一直是制约矩阵变换器工业化的一个关键因素.目前还没有具体的调制策略使电压传输比突破0.866.本文提出了一种调制策略,可以使电压传输比超过0.866,最大达到0.955.首先把矩阵变换器的变换过程虚拟为整流和逆变两个环节.整流阶段,采用输入电流空间矢量调制;逆变阶段,采用输出电压空间矢量过调制模式Ⅱ.接着消除中间直流环节,得到直接的交-交变换器.着重对逆变阶段进行了分析,给出了具体的控制算法,并推导出电压传输比的公式.最后进行了实验.结果表明:这种调制策略可以有效地提高电压传输比,具有一定的理论研究价值和应用前景,但增加了谐波,必须采取滤波措施. 相似文献
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以商用小型DC-DC变换器模块作为高压发生器,研制了一种微型程控高压电源。以数字电位器MCP42010和AT89S52为核心设计了输入电压调节、输出电流检测和故障监测及保护电路。应用程序采用汇编语言和图形化编程语言Labview编写。体积小、重量轻的优点使得该电源非常适用于芯片电泳电导检测等微型检测仪器中。 相似文献
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Anbukumar Kavitha Govindarajan Uma 《International Journal of Control, Automation and Systems》2010,8(6):1320-1329
DC-DC converters are widely used in power electronic systems where there is a need for stabilizing a given dc voltage to a
desired value. It has been reported that DC-DC converters exhibit different non-linear phenomena including bifurcations, quasi-periodicity
and chaos under both voltage mode and current mode control schemes. In this work, current mode controlled SEPIC converter
operating in continuous conduction mode is considered and by varying the reference current Iref, the converter exhibits chaos. It has been observed that the system changes from a stable buck-like operation to an unstable
boost-like operation by varying Iref. Bifurcation diagram is plotted for control signal and capacitor voltage with Iref as bifurcation parameter. Resonant parametric perturbation control technique has been applied to suppress chaos. Effects
of phase shift and frequency mismatch are also analyzed. With phase shift, control power required for suppressing chaos has
been reduced. Also intermittent chaotic stages are suppressed with the effect of frequency mismatch at the expense of increasing
control power. The stability analysis in SEPIC converter is performed by means of discrete model and is validated through
the simulated and experimental results. 相似文献
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One of the key components in the current mode control of power converters is the sensing of inductor current. Traditional low cost implementation is to add a sensing resistor in series with the inductor to sense the inductor current. This will reduce the overall efficiency of the power converter. An alternative is to apply a current transformer to the inductor to sense its current. This however will significantly increase the cost of power converters. One low cost implementation is to add a resistor–capacitor network in parallel with the inductor so that the inductor current can be derived from the capacitor voltage. The problem of this implementation is that the capacitor voltage is very sensitive to temperature variations. In this paper, a simple feedback loop is applied to the sensed capacitor voltage based on the steady state duty ratio of power converters such that the sensed inductor current will be independent of temperature variations. The sensing element with feedback compensation can be applied to inductors fitted to power converters such as buck converters and boost converters. Although experimental studies based on a buck converter were carried out to illustrate the correctness of the new sensing technique, the proposed technique is applicable to other converter topologies. 相似文献