共查询到19条相似文献,搜索用时 156 毫秒
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研究了行波管高压电源中变压器的铁芯损耗、绕组损耗(铜损)和工作频率,主要通过理论推导和仿真对磁性元件的设计进行了优化分析,并用PC95材质PQ40/40磁芯设计了一种输出电压10kV、输出功率450 W的行波管高压电源变压器。变压器设计结果满足电源要求,实验结果验证了理论分析。 相似文献
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摘要:针对推挽DC/DC变换器,功率超过1kw时,随输出功率增加,开关管关断时次级漏感引起MOSFET尖峰增加,同时MOSFET开通损耗加大。提出一种双变压器LC串联谐振软开关电路,两个变压器采用初级绕组并联,次级绕组串联,实现LC串联谐振软开关,实现MOSFET在零电压下开通或零电流下关断,从而降低开关管开通与关断漏感引起的尖峰。给出了电路结构图和软开关原理,并分析电路工作过程,根据原理,电路采用两个EE65B高频磁芯变压器,制作48V输入、380V直流输出的3kw的DC/DC LC串联谐振变换器。实验证明,通过对比MOSFET的漏源极电压实验数据,串联谐振电路可以大幅度减小MOSFET开通损耗与关闭时漏感引起的尖峰值。 相似文献
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介绍了一种小型新颖的叠片式高压脉冲变压器。采用PCB工艺制作变压器绕组,使绕组和磁芯结合紧密。这种变压器具有体积小、重量轻、低漏感以及交流电阻小的特性,为小型化平面化高压变压器设计提供了技术和经验。 相似文献
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<正> 在自己绕制变压器时,常因吃不准次级绕组究竟绕多少才能使变压器在加载时输出的电压正好是我们要求的电压,因为变压器空载时输出的电压都要比加载时输出的电压高一些,甚至高出很多,例如一种电子琴使用的9V电源,空载时其输出电压竟高达14.5V,但接入电子琴之后却接近9V。造成变压器空载时输出电压高于有载时输出电压的原因是变压器自身存在一定的内阻。在没有动手绕制变压器之前,如果能预先估算出变压器的内阻,这个问题就会迎刃而解。下面介绍一种预先估算变压器内阻的方法,供广大电子爱好者参考。首先根据铁芯截面积、输出电流、输出电压V2、输入电压V1计算出变压器初级绕组的匝数N1和线径d1,次级绕组的匝数N2和线径d2。第二步是根据变压器线圈骨架的尺寸(如附图所示)、匝数和线径,计算出初级绕组及次级绕组线圈的总长度。假如初级绕组绕在里面,次级绕组绕在外面,对初级绕组来说,每层漆包线可绕的匝数C1=L/d1,需要绕的层数为e1=N1/ 相似文献
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本机电路由电源板、功放板、DVD解码板、机心、卡拉OK板几大块组成。下面分别介绍其开关电源、解码电路和功放电路,同时提供维修实例以供参考。 一、电源部分 1.工作原理 本机开关电源采用脉宽调制方式,选用脉宽调制器方式的UC3845,产生的驱动信号直接控制功率开关管SSH11N90。其原理电路如图1所示。 高频变压器BT在电路中起能量储存、隔离输出和电压变换的作用,该高频变压器采用反激式绕法,初级绕组NP与次级绕组NS、反馈绕组NF的极性相反。当初级导通时, 相似文献
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Susanne Nell 《电子设计技术》2006,13(4):92-92,94
本设计实例是对以往设计实例的扩展(参考文献1)。原版采用一个电流变压器,它的次级绕组构成一个振荡器振荡回路的一部分。正常条件下,流经电流变压器单匝初级绕组的直流电流不会使电路保持振荡,直到初级电流停止流动。虽然这个电路起到一个断电检测器的作用, 相似文献
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A new type of sliding transformer with long magnetic core and movable secondary winding is presented. The basic transformer configurations and wiring are described. The magnetic flux distribution along the magnetic circuit and its influence on transformer parameters are discussed and examined. Also, the leakage inductance of the transformer primary winding, as the main cause of voltage drop and energy losses, has been discussed. The main experimental results of transformer model investigation are presented in this paper 相似文献
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《Power Electronics, IEEE Transactions on》2006,21(5):1167-1175
The frequency dependent characteristics of a gapped toroidal structure are extracted empirically over a bandwidth that exceeds 30MHz. The analysis is complicated due to nonlinear flux distributions, magnetic properties of the core material, leakage inductance, stray capacitances, and eddy currents in the windings. A permeance model of the core is implemented to model the magnetic circuit. The model includes a linear lumped element equivalent circuit to approximate the nonlinear complex permeability of the core, which was measured empirically. Stray capacitance and inductance of the winding are also modeled. A gyrator is used to couple the electric and magnetic models for circuit simulation. The measured and simulated results of open-circuit impedance from the secondary winding and the transimpedance gain (V/A) of the current sensor are compared and discussed. 相似文献
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基于漏磁信号的钢丝绳检测技术研究 总被引:4,自引:1,他引:3
主要讨论了钢丝绳局部缺陷(LF)和金属截面积损失(LMA)无损检测的原理,提出了一种基于漏磁信号的无损检测方法。利用永久磁铁对钢丝绳进行永久磁化,然后利用霍尔元件检测钢丝绳的磁场信号,对钢丝绳被永久磁化后的漏磁场峰-峰值与钢丝绳截面积间的关系进行了大量实验,经过数据分析和深入研究,得到了钢丝绳在截面断丝损伤类型下的峰-峰值与断丝间的关系。在此基础上研制了智能钢丝绳LF无损检测仪器,该仪器基于霍尔元件检测钢丝绳径向漏磁通的原理,用AT89C51单片机组成的检测系统,使用简单方便,具有工业实用价值和较高的性价比。 相似文献
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变压器的漏感是电磁干扰的主要来源之一,这是因为开关管在高速关断时,在变压器的漏感上产生感应电动势,叠加在变压器绕组的关断电压上,形成关断电压尖峰,这些电压尖峰不但造成电磁干扰,还会使开关管的电压应力增大,重者可能击穿开关管,并增大开关损耗,降低开关电源的效率。本文提出一种分布磁路结构的低漏感平面变压器,其原边绕组的匝数降低为一匝,副边绕组的等效匝数降低为小于一匝,因而漏感显著减小,这种分布磁路结构可以用于低压大电流电源的变压器,其有效性通过Maxwell 3D得到验证。 相似文献
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A two-inductor boost converter topology has conduction loss and transformer utilization advantages in converting low-voltage higher current inputs to high output voltages. In this letter, a new zero-voltage switching (ZVS) two-inductor boost converter with integrated magnetics is proposed. In the new topology, the two current source inductors, a resonant inductor and a two-winding transformer, are integrated into one single magnetic core with three windings. Two windings simultaneously perform the functions of the current source inductors and the transformer primary. The transformer leakage inductance forms the resonant inductance. This leads to a much more compact converter design with a significant reduction in the number of core and winding components. A theoretical analysis establishes the operating point of the ZVS converter. Both of the theoretical and experimental waveforms, including flux waveforms for the legs of the integrated core structure, are presented at the end of the letter. 相似文献
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Jianke Sheng Qiaofu Chen Jianxing Ke Zhengchun Jia 《International Journal of Electronics》2013,100(11-12):707-720
A novel principle of magnetic flux compensation of a linear transformer is proposed. The current of the primary winding is detected and multiplied by a compensation coefficient to get a reference current, which is tracked by a voltage source inverter to produce a compensation current. This compensation current is injected inversely in phase into the secondary winding. According to the law of superposition and the transformer's voltage equations, the main magnetic flux in the transformer and the equivalent impedance of the primary winding correlate linearly with the current compensation coefficient, and this equivalent impedance varies linearly with the current compensation coefficient. This new principle can be widely applied in power systems, such as series hybrid active power filter, fault current limiter, continuously controllable reactor, arc suppression coil and power system load flow control, and many FACTS devices can be implemented in terms of the new principle. A current control scheme is analysed. The theory is validated by experimental results, and some new devices based on the principle are discussed. 相似文献
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A contactless energy transmission system is essential to supply on-board systems of magnetic levitated vehicles without physical contact to a guiding rail e.g. in clean room environment. This paper introduces a combined contactless power supply (CPS) and electromagnetic guiding system (MGS). The actuator of the linear guiding system is part of an inductive energy transmission. With this approach two devices are integrated in one entity. The hybrid actuator consists of an omega shape iron yoke with permanent magnets and coils on its lateral arms. A concentrated primary winding is added to the elevator shaft and a secondary winding is wound on the central arm. Hereby a superposition of the MGS flux and the CPS flux emerges in the magnetic circuit of the actuator. A decoupling of the two systems is achieved by the high frequency of the CPS flux compared to the MGS flux. The proposed system requires less construction space and weight compared to existing energy transmission systems. 相似文献
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Design considerations for transformers utilized in high-power high-frequency DC/DC converters are addressed. Major areas of concern are core-material selection, minimization of copper losses due to skin and proximity effects, and the realization of controlled leakage inductances. Coreless characteristics for various high-frequency materials are presented, and the influence of various conventional winding arrangements on the copper losses and leakage field is also demonstrated. Coaxial winding techniques (used commonly in high-frequency transformers) are investigated next as a feasible solution for containing the leakage flux within the interwinding space, thus preventing it from permeating the core and resulting in lower core losses and the avoidance of localized heating. Added benefits of this technique are reduced forces within the transformer, lower copper losses, and robust construction. The performances of two experimental single-phase 50 kW, 50 kHz units are reported. A three-phase version of coaxially wound transformers is also presented 相似文献
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We introduce here a new transformer/inductor technology which is suitable for integrated power for multichip modules (MCM), microprocessors and chip sets. The transformer/inductor is embedded within the ceramic substrate, as are the chips and other components. It provides for extremely tight secondary side circuit layouts with very low and fixed leakage inductance. The core is a new multipole structure which can be considered as a number of transformers integrated into one monolithic structure. The core consists of a bottom ferrite plate, and the winding is constructed using high density interconnect techniques (HDI), such as laminating dielectric layers and depositing winding metals using sputtering followed by electroplating. Winding patterns are etched using photo-resist and wet etching techniques. Multiple vias are used to connect different primary and secondary winding layers. A conformal metal mask is used to laser-drill through (large) holes for the posts of the top part of the core. An experimental 50-W, six-pole transformer has been built using these techniques. It operates at 1.0MHz with efficiency approaching 98.7% and has a net height of about 0.09in (/spl sim/2.3mm). It has a power density of 71W/cc (or 1170W/in/sup 3/) and a surface power density of 17W/cm/sup 2/. 相似文献