共查询到19条相似文献,搜索用时 154 毫秒
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针对LED照明驱动电源小体积、低成本的要求,将原边反馈技术应用到反激式LED驱动电源中.开展了原边反馈电路工作原理分析,建立了驱动输出电流与原边MOS管电流、反馈绕组电压波形之间的关系;讨论了电路PFC部分的工作原理,副边二极管导通时间精确测量的方法,以及电路的各种保护;提出了通过调整变压器原边电感量使MOS管工作于准谐振状态,以提高整机工作效率的方法;推导了原边反馈反激电路变压器通用的设计方法,并以18W的LED日光灯驱动电源为例给出了设计步骤;最后,将原型机和同样规格的副边反馈的反激驱动电源进行了对比实验.实验及研究结果表明:采用原边反馈结构以后,LED照明驱动电源电路板面积明显缩小,元器件总数减少了1/3,效率提高了2%,其他电气性能相当,具有较高的实用价值. 相似文献
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《机械工程与自动化》2020,(5)
反激变压器是点火装置的核心部件,起到能量储存及传递的作用。详细论述了气隙与漏感对变压器性能的影响,并结合Saber软件,仿真分析了不同漏感变压器对电路的影响,最后结合实例进行了对比验证,仿真与实验结果吻合。研究结果为后续点火装置反激变换电路设计提供了理论依据,从而可提高产品工作的可靠性。 相似文献
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针对电力机车用高漏感变压器在运行中常出现的三相输出电压不平衡问题,以新型集成电抗器于一体的电力机车辅助电源逆变输出变压器为研究对象,通过建立电压闭环PWM调制以达到平衡三相输出电压和提高变压器供电质量的目的。建立了变压器与电抗器的高漏感磁集成模型,通过能量法计算得到高漏感变压器的漏感参数,并与低通滤波器的电抗器参数相匹配;基于Simulink进行高漏感变压器的工况模拟,得到在实际运行过程中三相负载不稳定的情况下产生的三相输出电压不平衡问题;建立输出电压波形闭环控制回路,对逆变器的PWM开关信号输入进行调制。结果表明:利用能量法计算的变压器漏感值与实测值误差在10%以内,通过PWM调制瞬时电压闭环控制能有效抑制三相输出电压不平衡问题,提高逆变输出变压器的供电质量。 相似文献
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设计并实现了一种简单易行且适用于连续电流和断续电流两种模式的变压器设计方法,并利用此方法对基于TOPSwitch-GX的多输出反激式开关电源变压器进行了设计研究。对电源的实验波形进行分析,结果表明,开关电源交流电压输入在86V~265V的范围内都能够稳定输出直流电压,说明此变压器设计方法可行,降低了计算难度,为反激式变压器的快速设计提供了便利。 相似文献
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设计了一台用于电力系统操作电源模块的辅助电源,采用了一种适合于较高电压输入的双管反激变换器的拓扑,分析了其工作原理,介绍了峰值电流控制模式的特点,并给出了变压器的主要参数及其设计步骤.给出了设计,并调试成功了1台约60 W三相输入、8路隔离输出的直流开关电源.实验结果证明:该电路既保留了反激变换器的结构简单、易于多路输出等优点,又解决了其在高压场合的开关应力大和安全性问题,非常适合于较高电压输入、中小功率、多路输出的直流电源应用场合. 相似文献
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准谐振(QR)开关电源应用谐振原理实现开关管零电压导通,从而减小开关损耗.由于电路工作在临界导通模式,电源工作频率会随输入电压及负载的变化而变化,给设计工作造成一些困难.为确定变换器的工作频率,首先从准谐振零电压反激式软开关电源的原理入手,分析了开关周期中开关管漏、源级电压的变化,建立了各阶段时间与电路参数之间的关系,... 相似文献
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通过对单端正激逆变式孤焊电源的研究,提出其输出功率的数学表达式。研究表明,输入电路的型式和脉冲变压器的磁芯尺寸影响和限制逆变式弧焊电源的输出功率。同时,脉冲变压器漏感和输出整流二极管反向恢复时间的存在会导致输出脉宽的减小,也影响逆变电源的输出功率。 相似文献
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The static voltage distribution between winding turns has great impact on output characteristics and lifetime of the air-core spiral strip pulse transformer (ACSSPT). In this paper, winding inductance was calculated by electromagnetic theory, so that the static voltage distribution between turns of secondary winding of ACSSPT was analyzed conveniently. According to theoretical analysis, a voltage gradient because of the turn-to-turn capacitance was clearly noticeable across the ground turns. Simulation results of Pspice and CST EM Studio codes showed that the voltage distribution between turns of secondary winding had linear increments from the output turn to the ground turn. In experiment, the difference in increased voltage between the ground turns and the output turns of a 20-turns secondary winding is almost 50%, which is believed to be responsible for premature breakdown of the insulation, particularly between the ground turns. The experimental results demonstrated the theoretical analysis and simulation results, which had important value for stable and long lifetime ACSSPT design. A new ACSSPT with improved structure has been used successfully in intense electron beam accelerators steadily. 相似文献
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为了提高开关电源的功率密度,减小开关电源的体积和电磁干扰(EMI),降低功率开关器件的导通损耗,介绍了一种基于16565的准谐振反激式变换器.利用功率开关管自身的输出电容与变压器原边电感产生谐振,通过适当的控制实现了开关管的零电压导通.与传统的反激式硬开关变换器相比,它能有效地减小开关损耗,提高变换器的效率. 相似文献
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针对能馈式电子负载中的直流模块特殊要求—低压大电流输入、高增益、高效率,在分析传统拓扑和手段的基础上,介绍了一种新颖输入并联、输出串联拓扑,利用耦合电感提高电路的增益,采用新颖有源箝位实现了软开关.在该电路的基础上设计了一个交错并联变换器以满足这些大功率等级,并进一步减小了输入电流纹波.阐述了在此应用下该变流器中死区时... 相似文献
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Liu Z Winands GJ Yan K Pemen AJ Van Heesch EJ 《The Review of scientific instruments》2008,79(1):015104
A high ratio (winding ratio of 1:80) pulse transformer with a modular ferrite core was developed for a repetitive resonant charging system. The magnetic core is constructed from 68 small blocks of ferrites, glued together by epoxy resin. This allows a high degree of freedom in choosing core shape and size. Critical issues related to this modular design are the size tolerance of the individual ferrite blocks, the unavoidable air gap between the blocks, and the saturation of the core. To evaluate the swing of the flux density inside the core during the charging process, an equivalent circuit model was introduced. It was found that when a transformer is used in a resonant charging circuit, the minimal required volume of the magnetic material to keep the core unsaturated depends on the coupling coefficient of the transformer and is independent of the number of turns of the primary winding. Along the flux path, 17 small air gaps are present due to the inevitable joints between the ferrite blocks. The total air gap distance is about 0.67 mm. The primary and secondary windings have 16 turns and 1280 turns, respectively, and the actually obtained ratio is about 1:75.4. A coupling coefficient of 99.6% was obtained. Experimental results are in good agreement with the model, and the modular ferrite core works well. Using this transformer, the high-voltage capacitors can be charged up to more than 70 kV from a low-voltage capacitor with an initial charging voltage of about 965 V. With 26.9 J energy transfer, the increased flux density inside the core was about 0.23 T, and the core remains unsaturated. The energy transfer efficiency from the primary to the secondary was around 92%. 相似文献