倍频式IGBT高频感应加热电源的研究

倍频式感应加热电源负载输出频率为功率开关管工作频率的二倍，且功率开关器件工作时具有软开关特性，在需要高频应用的场合很有意义。文中以IGBT来实现倍频式高频感应加热电源，比较了不同频率比下的电路工作状态，得出电路工作在断态下更适合电路功率调节的结论。详细分析了断态下电路工作状况，得出直流等效电阻与交流负载等效电阻的关系，并给出了选取电路参数的经典方法。根据该方法设计了一台样机，通过实验验证了理论分析及参数选取方法的正确性。     

软开关推挽式高频链逆变器

提出一种新颖的单级式推挽高频链逆变器拓扑,变压器初级侧采用电源端串接一个开关管的三管推挽结构,次级侧采用双绕组全波式周波变换器结构。该类逆变器具有拓扑简洁、初次级开关管均可在宽输出电流区间范围内实现零电压开通、变换效率高等优点。电路采用正弦脉宽脉位调制策略,变压器初级侧辅助开关管的工作频率是另外2个开关管的2倍,除去死区时间,辅管的驱动信号逻辑上是另外2个开关管驱动信号的与非关系。详细分析了各工作模态,讨论了次级占空比丢失、软开关实现条件及特殊变压器设计的关键电路参数设计准则等。最后,制作了一台输入40~60 V DC、输出110V AC、额定功率660 W的原理样机,实验波形及较高的变换效率验证了所提拓扑的正确性。     

高频感应加热电源功率器件MOSFET驱动电路

针对多管并联的MOSFET驱动这一难题,通过分析MOSFET开关过程,得出了MOSFET开关转换对驱动电路的要求,以及驱动电流和驱动功率的计算方法,最后采用脉冲变压器法设计了高频感应加热电源功率器件的驱动电路,并给出了电路的设计参数及实验波形.     

高压开关电源变压器设计及其噪声干扰的抑制

从变压器设计的基本原理出发,提出了一种设计开关电源变压器的简便方法,即直接根据变压器的工作频率和所需输出的功率查表确定所需选用的磁性材料,从而确定变压器线包各参数;并对如何抑制电源变压器常见的噪声干扰进行了探讨.     

一种隔离型三端口双向LCLC多谐振直流变换器

提出一种隔离型多谐振双向三端口直流变换器。LCLC多谐振结构具有三个谐振频率,通过参数设计令三个谐振频率分别为基频和三倍频的串联谐振频率以及二倍频的并联谐振频率。由于多谐振腔具有基频和三倍频两个串联谐振频率,因此可以对变换器中的基频和三倍频能量进行传递,提高能量传递效率。谐振腔电流为基频和三倍频电流的叠加,有效地降低了谐振腔电流峰值。此外,变换器采用移相控制方法实现三个端口间功率的灵活控制,并且通过调节不同负载情况下的驱动频率,保证了全负载范围内三个端口所有开关管的零电压软开关(ZVS)特性,有效地抑制了变换器的开关损耗,保证全负载范围内的高效率。同时,变压器的漏感作为谐振电感的一部分,削弱了变压器寄生参数对电路特性的影响。最后,设计一台1.5k W实验样机,其正向和反向的最高效率分别为96.7%和96.9%,功率在0.5k W以上时双向效率均高于95.5%,证明了变换器在全负载范围内的高效率特性。实验结果验证了理论分析的正确性与可行性。     

高功率因数的大功率开关电镀电源研究

介绍一种大功率开关电镀电源的设计方案.为解决电镀电源中出现的电流严重畸变问题,采用三相PWM高功率因数整流方案,采用TMS320LF2812实现逆变器的FB-ZVSPWM控制方式,功率输出采用变压器功率合成及倍频整流模式,降低了开关损耗,有效提高了开关频率和输出效率.采用Mathb对其进行了仿真.仿真分析和实验结果验证了设计方案的可行性,证明了设计的电源具有谐波污染小,功率因数高,转换效率高等优点.     

三端口直流微网母线电压控制器及 多目标控制

提出一种混合储能三端口直流微网母线电压控制器及多目标控制方法。三端口母线电压控制器采用LCLC多谐振结构,可对基频和三倍频能量进行传递,提高能量传递效率。谐振腔电流为基频和三倍频电流的叠加,有效地降低了谐振腔电流峰值。针对LCLC多谐振三端口双向DC-DC变换器中变压器漏感导致超级电容端口与蓄电池端口之间存在功率耦合,无法实现独立控制的问题,建立了端口间的功率耦合模型,并提出了从变换器硬件参数以及驱动频率选择的角度出发减小功率耦合的方法。此外,提出了一种驱动频率最优化控制方法,根据变换器的输出功率调节工作频率,以保证变换器全负载范围内的软开关以及效率最优。同时,提出了兼顾直流母线电压波动快速调节、混合储能能量分配以及三端口变换器驱动频率最优的多目标控制策略。最后,设计一台1.5 kW实验样机,并模拟了直流微网功率波动实验场景。实验结果验证了拓扑结构、参数设计、三端口变换器多目标控制方法的可行性和有效性。     

并联LC网络的软开关三管推挽式直流变换器EI北大核心CSCD

提出一种采用3个开关管的软开关推挽电路。增加的开关管Q3串接在输入电源和变压器原边绕组中间抽头之间。一个LC网络并联在Q3两端。因为输出滤波电感能量大,2个原始的开关管能够在宽负载范围内实现零电压开通。并联的LC网络增加了Q3开通前变压器漏感中的能量,使得Q3也能在宽负载范围下实现零电压开通。分析电路各工作阶段原理,讨论软开关实现条件,阐述LC器件的设计。完成一台800W、开关频率为132kHz的原理样机,样机在86 W下就能实现所有开关管的零电压开通,样机最高效率达到94.14%。测试比较了所提电路和基本的三管推挽电路的效率,结果表明,所提电路在轻载下比基本电路效率高2.31%。     

混合式配电变压器有载调压开关的结构与参数设计

基于绝缘栅双极型晶体管(IGBT)的开关特性,通过在机械式有载调压开关中增加由IGBT和电力二极管构成的辅助切换电路,提出了一种混合式配电变压器有载调压开关结构及其参数的设计方法,所提结构在抽头切换时引入电力电子开关,利用电力电子开关的开关性能实现配变抽头的有载无弧调整。最后,在MATLAB/Simulink中搭建了混合式配电变压器有载调压开关的仿真模型,验证了所提混合式有载调压开关结构和参数设计方法的可行性。     

-带回馈变压器的新颖软开关推挽变换器

针对推挽变换器难于实现软开关的问题,提出了一种新颖的带回馈变压器的软开关辅助电路,使两个推挽功率开关管实现软开通和软关断。分析了电路的工作原理并推导出电路参数的计算公式。当回馈馈变压器的升压比和励磁电感满足设计条件时,可避免回馈变压器进入磁饱和状态。研制的实验样机投入实际应用,验证了电路和分析方法的正确性。     

全桥移相软开关的开关管损耗仿真及改善

采用全桥移相软开关技术,系统地设计了一套高频直流开关电源,介绍了软启动电路、全桥逆变电路、可饱和电感、高频变压器。采用仿真研究的方法,计算了开关管的损耗,并优选开关管并联电容等参数。研究结果表明,采用软开关技术更有利于发展大功率直流电源。     

Separately frequency modulated single-ended type quasi-current resonant DC/DC converter with high-frequency-link incorporating forward and flyback hybrid transformer

This paper considers an improved bidirectional zero-current switching (ZCS) quasi-resonant-type single-ended soft-switching mode dc/dc converter with an HF center-tapped transformer link and ZCS commutated diode rectifier which is capable of minimizing switching losses of a power device, its electrical stresses and electromagnetic interference (EMI/RFI) noises. This converter topology can operate efficiently under a simple frequency-regulation strategy in the ultrasonic frequency ranges. The advanced exact computer-aided simulating analysis of the new converter circuit is presented introducing the normalized frequency variable and circuit system parameters. The open-loop/closed-loop steady-state voltage regulation characteristics in a variable frequency-modulation mode are illustrated and discussed in the normalized general-purpose expressions in addition to the load variation performance. The feasible high-power density SMPS breadboard with a full-wave quasi-current resonant switch assembly using a single MOS-gate switching power semiconductor device is originally developed and investigated, and is optimally designed for a distributed low-voltage large-current power supply system. Its experimental results in the PFM control implementation are demonstrated compared with the exact simulation ones from a practical viewpoint.     

Pulse current regenerative resonant snubber‐assisted two‐switch flyback‐type ZVS PWM DC‐DC converter

In this paper, a two‐switch high‐frequency flyback transformer‐type zero voltage soft‐switching PWM DC‐DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of two active power switches and a flyback high‐frequency transformer. In addition to these, two passive lossless snubbers with power regeneration loops for energy recovery, consisting of a three‐winding auxiliary high‐frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this power converter has some advantages such as low cost circuit configuration, simple control scheme, and high efficiency. Its operating principle is described and to determine circuit parameters, some practical design considerations are discussed. The effectiveness of the proposed power converter is evaluated and compared with the hard switching PWM DC‐DC converter from an experimental point of view, and the comparative electromagnetic conduction and radiation noise characteristics of both DC‐DC power converter circuits are also depicted. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(3): 74–81, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20081     

Zero-current Switching Series Resonant High-voltage DC-DC Converter with Series-connected Primary Windings of Center-tapped Transformer

Abstract—This article proposes a novel zero-current switching series resonant inverter-fed voltage multiplier based high-voltage DC-DC converter. The series resonant inverter in the proposed topology has two power switches (insulated-gate bipolar transistors), two resonant capacitors, and only one high-voltage transformer with center-tapped primary windings. The power switches are connected in the form of a half-bridge network. The leakage inductances of the transformer's primary windings together with resonant capacitors form two series resonant circuits. The series resonant circuits are fed alternately by operating power switches with an interleaved half-switching cycle. The secondary winding of the high-voltage transformer is connected to a voltage multiplier circuit to rectify and boost the voltage. The converter operates in discontinuous conduction mode, and its output voltage is regulated by pulse-frequency modulation. Therefore, all the power switches turn ON and OFF at the zero-current switching condition. The main features of the proposed converter are lower power loss, less cost, and smaller size compared to previously proposed series resonant high-voltage DC-DC converters. The experimental results of a 130-W prototype of the proposed converter are presented both for dynamic and steady-state operation. The results confirm the excellent operation and performance of the converter.     

Controllable electronic transformer based on the resonance structure with switching capacitor for low-rise buildings residential area power supply stabilization systems

Based on a resonance structure with switching capacitor, a simple power circuit of high frequency controllable electronic supply line transformer having improved mass-size parameters and overvoltage protection of its transistor switches is considered. Analysis of its operation, formulae for calculation of power elements, regulating and load characteristics are presented.     

一种全波整流有源箝位ZVS正激变换器的研究

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载,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。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。     

开关电源中高频变压器工作模式的研究

将开关电源中变压器的工作模式分三类 ,着重对变压器二次侧短路和开路两种特殊模式的工作原理及在实际电路中的应用进行分析 ,有助于应用变压器特殊工作模式进行开关电源变压器及新型零开关电路拓扑的设计。     

LLC resonant DC–DC converter with series‐connected primary windings of transformer

This paper proposes a zero‐voltage switching (ZVS) LLC resonant step up DC–DC converter with series‐connected primary windings of the transformer. The series resonant inverter in the proposed topology has two power switches (MOSFETs), two resonant capacitors, two resonant inductors, and only one transformer with center‐tapped primary windings. The power switches are connected in the form of a half‐bridge network. Resonant capacitors and inductors along with the primary windings of the transformer form two series resonant circuits. The series resonant circuits are fed alternately by operating the power switches with an interleaved half switching cycle. The secondary winding of transformer is connected to a bridge rectifier circuit to rectify the output voltage. The converter operates within a narrow frequency range below the resonance frequency to achieve ZVS, and its output power is regulated by pulse frequency modulation. The converter has lower conduction and switching losses and therefore higher efficiency. The experimental results of a 500‐W prototype of proposed converter are presented. The results confirm the good operation and performance of the converter. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于无缝切换技术的三相不平衡换相开关研究与设计

应用三相不平衡换相开关可缓解低压配电网中三相电流不平衡现象,但目前分换相开关的相序切换原理过于简单,存在换相过程断电时间长、电压和电流畸变严重等问题,限制了其广泛应用。为此,提出了一种以功率因数校正电路与逆变器电路为基础,由初始阶段、当前相跟踪阶段、切换相跟踪阶段以及换相完成阶段4个阶段组成的整体换相方案。首先通过功率因数校正电路与逆变电路使得将要相互切换的两相的电压调整为同幅、同频与同相,然后电力电子开关完成换相动作,最终实现相间的无缝切换。仿真与实验结果表明,所提出的方案保证了换相过程的不间断供电,同时改善了电压和电流的畸变问题。     

基于电流型脉宽调制器的单端反激式稳压电源设计

介绍了一种以UC3842电流型脉宽调制器进行控制,多路固定电压输出的40W开关稳压电源.根据UC3842的特性给出了详细的电路参数及高频变压器的设计方法,并对其性能进行实验,实验结果表明按此方法设计的开关稳压电源可靠性高。