共查询到19条相似文献,搜索用时 125 毫秒
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为强化DC/DC变换技术的实践教学,基于多绕组变压器和反激电路原理,开发一套DC/DC变换器教学系统。设计变换器的拓扑结构,分析工作原理及控制策略,计算变换器系统参数,建立数字仿真模型,设计变换器主电路、输出电压采样电路、开关管驱动电路等来搭建变换器实验平台。实验教学应用表明,该变换器实现宽输入/输出电压范围功能的同时,能够提高学生的电力电子技术综合实践能力。 相似文献
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为了提高小型风力发电系统输出电能质量,设计了高效、可靠、低成本的正弦波逆变器。主电路由推挽升压变换器和单相逆变桥组成,采用高频变压器实现电压比调整和电气隔离,降低了噪声,提高了效率、减小了输出电压纹波。逆变器功率开关管采用了RCVD缓冲电路,确保逆变桥安全工作。控制部分采用集成脉宽调制芯片SG3524和正弦函数发生芯片ICL8038实现正弦波脉宽调制(SPWM),简单可靠、易于调试。实验样机体积减小到传统逆变器的1/4,效率达到86%。实验结果表明输出电压波形失真度小于5%,在复杂的工况下实现了220 V/50 Hz的市电输出。 相似文献
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固态变压器是一种将电力电子技术运用到电力变压器中的新型电气设备,固态变压器隔离级采用DAB变换器?适 用于大功率场合,易于实现零电压关联ZVS(Zero Voltage Switching),基于移相控制,通过改变移相占空比来调节传输功率和能量的流动方向,通过在闭环控制中引入补偿环节,消除了系统的静态误差,提高了动态响应速度,搭建仿真模型,验证了移相控制下DAB变换器的工作状态,通过基于 TMS320F28335的实验平台验证了DAB变换器能够实现直流变压功能,并且输出电压能够稳定在设定值,最终经逆变级产生了工频交流电压,验证了控制策略的有效性。 相似文献
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1开关型稳压器开关型稳压器通常利用电感、变压器或电容器作为储能元件来将输入能量传递给输出负载。其反馈电路用于调节能量的传输 ,保证在限定的负载电流范围内保持恒定的输出电压。转换器的基本电路结构包括升压型、降压型和反相型等 ,图1所示是DC -DC变换器的几种典型结构 ,当利用变压器作储能元件时 ,可以实现输出与输入之间的隔离。在电池供电系统中选择开关型DC -DC转换器可以获得较高的效率和较低的热耗 ,从而可有效延长电池的使用寿命。同时通过在输出级添加适当的滤波电路 ,还能够将输出电压纹波降至较小的范围。2开关… 相似文献
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《中国无线电电子学文摘》2005,(2)
TM42 2005020574 单级桥式P FC电路功率变压器偏磁的产生机理分析/贵洪奇,金祖 敏,王凤平(哈尔滨工业大学)刀哈尔滨工业大学学报,一2 004,36(9 )一1215一1219 提出一种单级全桥软开关功率因数校正电路,它采用移相控制方式,能 同时实现功率因数校正、软开关、输出电压调节和电气隔离.但由于电路 特殊的控制方式和所要实现的功率因数校正功能,该校正电路中的功率 变压器除存在普通全桥变换器产生偏磁的原因外,还存在产生偏磁的特 殊因素.该文在分析变换器的电路结构和工作原理之后,对偏磁的产生 机理进行了分析,指出了该变换器影响偏磁大小… 相似文献
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提出了一种应用于48 V-1 V系统的隔离型混合模式降压变换器,利用飞电容和变压器实现高转换比应用下的高转换效率。混合变换器结合了开关电容变换器和开关电感变换器,其中飞电容承担了部分电压降,实现了功率开关管电压应力的降低。由于开关节点处的电压摆幅较小,开关损耗随之减小;通过使用更低压的功率开关管,实现功率开关管导通损耗减小。在此基础上,隔离型混合模式降压变换器通过时序控制可以实现软开关,进而实现功率开关管开关损耗减小,使得整体效率提升。在隔离型混合模式降压变换器中,飞电容还具有隔直电容的作用,可以防止变压器偏磁。在典型应用下,即在48 V输入电压、1 V输出电压、500 kHz开关频率下,峰值效率为94.84%。 相似文献
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本文阐述了HSC1201型集成高压变换器的设计原理,即采用自激振荡电路和变压器升压,实现高压变换。同时,利用变压器低压绕组完成电压反馈控制,以稳定输出电压(3700V)。该产品的研制成功大大地减小了产品的体积,提高了产品的可靠性。 相似文献
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Very small manually wound transformers for sub-watt DC-DC converters are notorious for their relatively high cost and low reliability. In this paper, an isolated low-profile low-power 8 MHz soft-switching power converter using a coreless printed circuit board (PCB) transformer is described. Coreless PCB transformers eliminate several problems of their core-based counterparts in low-power applications. The diameter of the coreless PCB transformer is merely 0.46 cm. The converter's power output is about 0.5 W with a typical transformer efficiency of 63%. The high-frequency capability, high reliability and the low-profile structure make coreless PCB transformers a viable and attractive option for reliable mega-hertz switching converters and micro-circuits 相似文献
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Some electromagnetic aspects of coreless PCB transformers 总被引:2,自引:0,他引:2
In this paper, some EMI aspects of using coreless PCB transformers are addressed. Based on the antennas theory, the radiated power of a coreless PCB transformer is estimated and found to be negligible. The electromagnetic field plot of a power electronic circuit using a gate drive circuit isolated by a coreless PCB transformer has been recorded. The major radiated EMI source in the frequency range of 30 MHz to 300 MHz is found to be the copper tracks of the power circuit, where switching transients occur, rather than the coreless PCB transformer. Coreless PCB transformers essentially operate at relatively low frequency (8 MHz in this case) by near-field magnetic coupling. Experimental results have confirmed that the application of coreless PCB transformer in gate drive circuit will not impose any serious EMI problem on the power electronic circuit 相似文献
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This paper describes the modeling and implementation of a coreless printed circuit board (PCB)-based transformer with “multiple” secondary outputs. This new PCB transformer has been successfully applied in complementary gate drive circuits in a novel low-profile power converter with high-power density and a converter bridge. The PCB-based transformers do not require the manual winding procedure and thus simplify the manufacturing process of transformer-isolated gate drive circuits. The use of the multiple secondary outputs can in principle simplify the complementary gate drive circuits that are often required in many power electronics applications 相似文献
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The authors report the use of a coreless printed circuit board transformer for power conversion with very high power density and efficiency. A coreless PCB transformer with an outermost radius of /spl sim/1 cm and 19 turns for both the primary and secondary windings can transfer 19 W at an efficiency of 90%, resulting in a record power density of 24 W/cm/sup 2/. The power density and energy efficiency of a coreless PCB transformer are higher than those of core-based microtransformers. Coreless transformers are simpler in structure, easier to implement in silicon wafer and cheaper than core-based planar transformers. 相似文献
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采用现代化印刷版技术,首先设计制作出一种基于柔性PCB板、线圈宽度为0.2mm、线间距为0.3mm、匝数比为6:18的空心变压器,然后采用直流磁控溅射在其上下表面镀上软磁薄膜,而最终制成了一种薄膜PCB平面变压器。研究了薄膜材料、膜厚等因素对该种变压器性能的影响。结果表明,制得的薄膜PCB平面变压器可以有效工作于4~14MHz的频率范围。采用上述方法制备变压器,可以把变压器从三维变成两维,从而为器件的表面贴装打下基础,并同时满足"更小,更轻,更薄"的要求。 相似文献
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A novel one-stage forward-type power-factor-correction circuit 总被引:1,自引:0,他引:1
A novel power-factor-correction (PFC) circuit is proposed which is constructed with one stage by using a single forward converter. This PFC circuit has functions of high power factor and suppression of the output voltage ripple. The high power factor is accomplished by making the PFC circuit operate in the discontinuous conduction mode and the suppression of the output voltage ripple by using the exciting energy of the transformer in the forward converter 相似文献
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一种新颖有源箝位ZVS正激变换器的研究 总被引:2,自引:0,他引:2
介绍了一种中心抽头全波整流有源箝位ZVS正激变换器的工作原理及主要参数计算。有源箝位电路由一个箝位开关管和箝位电容组成。变压器磁芯实现无损复位,励磁能量和漏感能量全部传递到负栽.磁芯利用率高,功率开关管承受电压应力降低。通过变压器漏感与开关管输出电容的谐振,主开关管与箝位开关管都可以实现ZVS开通,提高了变换器工作效率。文章首先分析了变换器工作原理,然后给出了主要参数的计算方法,最后通过样机(48V输入5V/20A输出)实验验证了该拓扑的高效性能。 相似文献
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《Industrial Electronics, IEEE Transactions on》2008,55(8):2974-2983