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基于SG1525的PFM-PWM控制谐振DC/DC变换器 总被引:1,自引:0,他引:1
设计了基于SG1525宽温度工作范围的340 W LLC谐振DC/DC变换器。介绍了一种利用集成控制芯片SG1525来实现脉冲频率调制(PFM)-脉宽调制(PWM)控制的方法。为解决轻载或空载时LLC谐振变换器工作频率太高、损耗大的问题,提出了在轻载或空载时采用PWM控制的策略,并提出了实现电路。最后在340 W样机上进行了实验验证,证明了利用SG1525可以实现PFM控制和轻载时的PWM控制。该电路结构简单,参数设计灵活,且可以实现变频控制和PWM控制的无缝切换,很好地满足了宽温度要求。 相似文献
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针对一种双管正激DC/DC直流变换器,研究了其电路工作原理,对电路工作时的功率损耗及其分布进行了分析。并给出了不同电路参数条件下的损耗及效率计算结果,在此基础上优化设计了150W的原理样机。试验与测量结果表明对变换器损耗计算的准确性和优化设计的可行性。 相似文献
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在软开关Boost变换器基础上,通过引入Flyback单元,提出了一种高升压增益软开关DC-DC变换器,进一步提高了变换器的电压增益,避免了高占空比,减小了开关管电压应力。因此,可选取低电压等级低导通电阻MOSFET以降低变换器的成本,提高变换器的效率。在开关管关断期间,漏感能量向负载传递,有效利用了漏感能量,且无需额外的吸收电路。此外,变换器实现了开关管的零电压(ZVS)导通和二极管的零电流(ZCS)关断,进而消除了开关管的开通损耗和二极管的反向恢复损耗。研究了高升压增益软开关DC-DC变换器电路的工作特性和占空比丢失的主要原因,分析了该变换器的元器件应力及电路损耗。设计了一台160W的实验样机,实验结果验证了理论分析的正确性。 相似文献
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一类新的辅助开关零电流关断的零电压过渡PWM软开关拓扑 总被引:2,自引:1,他引:1
分析了零电压过渡PWM软开关电路存在的辅助开关硬关断的问题,提出了一类新的辅助开关零电流关断的拓扑,并介绍了其工作原理。在功率为290W的升压型电路和功率为100W的正激型电路装置上进行的实验,证明了拓扑的可行性,电路效率比传统的零电压过渡PWM电路高。 相似文献
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单级PFC结构简单,成本低,详细地介绍了一种基于不对称半桥的单级不对称半桥变换器,分析了它的工作原理及主要参数选择,并用实验验证了其实现PFC和ZVS的特性。 相似文献
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近年来,软开关技术得到广泛的发展与应用,出现不少高效率的电路拓扑,其中不对称半桥就是典型的适用于中低功率的直流变换电路。它充分利用电路本身的分布特性,利用变压器漏感和开关寄生电容的谐振来实现零电压开关,减少了开关的导通损耗。介绍了一种在变压器原边带箝位电路的不对称半桥零电压开关电路。该箝位电路能明显减少输出二板管的反向恢复效应,提高变换器的效率。并对该软开关电路的工作原理和实现方法做了详细的分析,通过一台300W,100kHz的实验样机,证实了该方法的有效性。 相似文献
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一种多路输入高升压Boost变换器 总被引:9,自引:0,他引:9
针对光伏发电系统模块多、输出电压低等问题,提出了一种多路输入高升压Boost变换器。首先分析了2路输入高升压Boost变换器的工作原理及性能特点,然后通过拓扑推演,得到了n路输入高升压Boost变换器。在此基础上搭建了输出功率为100 W的实验样机,实验结果表明:n路输入电压平衡时,输出电压与输入电压之比是Boost变换器的n倍;控制简单,无论各个输入电压源电压相等与否,均可以通过一套控制系统实现输出电压恒定;开关器件电压应力低,可以选择额定电压低的器件,有利于提高变换器效率。 相似文献
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一种新型结合的软开关电路研究 总被引:1,自引:0,他引:1
简要分析了一种新型BoostPFC与Flyback结合的软开关电路。采用简单方法和常用元器件对其进行了有效的控制。研制了一台148kHz样机,其Boost变换器的输出为400V/175W,Flyback的输出为12V/36W,整机功率为212W,最高效率达93.7%,并对其进行了综合性能评价。证实了所提控制方法简单有效,说明了该软开关电路可实现所有开关的软开关,具有一定的应用价值。 相似文献
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GAKU YAMAMOTO DAISUKE GUNJI TAKEHIRO IMURA HIROSHI FUJIMOTO 《Electrical Engineering in Japan》2017,199(4):44-54
The authors have developed a wireless power transfer (WPT) system for an in‐wheel motor (IWM). It is called a wireless in‐wheel motor (W‐IWM). This paper presents a method that enhances the WPT efficiency in this system. Some methods that maximize the power transfer efficiency by power converter control have been proposed in the past WPT research. In this research, a dc‐dc converter is inserted on the receiver side to vary the load state. However, the space on the receiver side is very small for the W‐IWM; therefore, it is preferable to make the secondary circuit small. Therefore, a full bridge converter is used instead of a dc‐dc converter in the W‐IWM. In this paper, the authors propose a theoretical formula for the transfer efficiency of the IW‐IWM. From an analysis of this formula, there is a combination of a primary voltage and load voltage that maximize the efficiency. The feasibility is validated by an experiment using a motor bench set. 相似文献
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Pham Phu Hieu Yao‐Ching Hsieh Jing‐Yuan Lin Bing‐Siang Huang Huang‐Jen Chiu 《International Journal of Circuit Theory and Applications》2018,46(4):868-881
An active‐clamp zero‐voltage‐switching (ZVS) buck‐boost converter is proposed in this paper to improve the performance of converter in light load condition. By employing a small resonant inductor, the ZVS range of switches could be adjusted to very light load condition. Moreover, 2 clamping capacitors are added in the converter to eliminate the voltage spike on the switches during transition. The operating principle of the proposed converter is analyzed, and the optimal design guide for full range ZVS is also provided. A 60‐W output prototype is experimentally built and tested in laboratory to verify the feasibility of proposed converter. The measured results show the critical ZVS operation of power switches at 1 and 0.7‐W output power for buck and boost mode, respectively. The peak conversion efficiency is up to 92.3%. 相似文献
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An interleaved pulse‐width modulation (PWM) converter with less power switches is presented in this paper. The buck type of active clamp circuit is used to recycle the energy stored in the leakage inductor of a transformer. The zero voltage switching (ZVS) turn‐on of power switches is realized by the resonance during the transition interval of power switches. At the secondary side of transformers, two full‐wave rectifiers with dual‐output configuration are connected in parallel to reduce the current stresses of the secondary windings of transformers. In the proposed converter, power switches can accomplish two functions of the interleaved PWM modulation and active clamp feature at the same time. Therefore, the circuit components in the proposed converter are less than that of the conventional interleaved ZVS forward converter. The operation principle and system analysis of the proposed converter are provided in detail. Experimental results for a 280 W prototype operated at 100 kHz are provided to demonstrate the effectiveness of the proposed converter. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献