并联型双耦合绕组反激式单级PFC变换器

在双耦合绕组反激式单级PFC变换拓扑的基础上,引入并联功率传递单元,提出一种并联型双耦合绕组反激式单级PFC变换拓扑.该拓扑通过在Boost电感上增加二次绕组,使部分能量直接由Boost电感传给负载,从而提高了变换器的效率,并且能够限制中间储能电容电压和减小开关器件的电压电流应力.本文详细分析了该变换拓扑的工作原理和稳态特性,讨论了变换器的参数设计.150W/24V样机实验结果表明该拓扑具有高效率、高功率因数、低开关电压应力等特点.     

双耦合绕组反激式单级PFC变换器

提出了一种新颖的反激式单级PFC变换器拓扑.该拓扑由Boost功率因数校正(PFC)电路和具有双耦合绕组的反激变换电路组合而成,中间储能环节由两个电容构成,除了存储Boost电感能量和作为反激变换器电源之外,还分别用于吸收变压器两个初级绕组的漏感能量,因此能有效抑制功率器件的电压应力.详细分析了该变换器的工作原理和稳态特性;讨论了Boost电感和反激变压器的参数设计.实验结果表明,该变换器具有功率因数高,功率开关电压应力低,中间储能电容电压波动小等特点.     

一种具有宽输出调压范围与低电压应力的单级无桥隔离型PFC变换器

针对单级无桥隔离型功率因数校正(PFC)变换器存在开关管电压应力大,工作于降压模式时,总谐波畸变率(THD)高、功率因数(PF)低的问题,提出一种具有宽输出调压范围与低电压应力的单级无桥隔离型PFC变换器.该变换器采用双绕组分裂电容的结构,降低了开关管与二极管的电压应力.通过引入工频开关管,消除变换器工作于降压模式时的...     

应用直接功率传递原理改进的单级PFC拓扑及其直流母线电压应力分析

过高的直流母线电压应力(即中间储能电容电压应力)是困扰单级功率因数校正AC／DC变换器的一个严重问题。本文分析了单级功率校正AC／DC变换器产生高电容电压应力的原因,介绍了三种典型的根据直接功率传递原理改进的单级PFC变换器拓扑,对这几个拓扑的直流母线电压应力进行了深入的分析和比较。     

双绕组反激式单级PFC变换器及功率因数改善措施研究

为改善功率变换器的功率因数,提出一种双绕组反激式单级功率因数校正PFC(Power Factor Correction)变换拓扑。该拓扑由Boost PFC电路和具有串并联结构的双绕组反激变换电路组合而成,利用2个中间储能电容吸收变压器初级绕组的漏感能量,有效地抑制功率器件的电压应力,提高变换器的可靠性。详细分析了变换器的工作原理和稳态特性,并在传统的单电压环控制方法的基础上,将整流电压引入到控制电路,提出了一种简单的电压补偿控制方法来提高变换器的功率因数、降低输入电流的总谐波畸变率。设计制作了一台150 W/24 V实验样机,实验结果验证了所提出电路原理的正确性和采用电压补偿控制方法改善输入电流波形质量的有效性。     

一种新型交错式反激变换器分析与设计

提出了一种新型交错式反激变换器拓扑。利用变压器漏感与开关管并联电容、钳位电容间的谐振,实现了开关管的零电压导通(ZVS),并消除了开关管关断时所产生的电压尖峰,减小了电压应力。该变换器具有拓扑简单、实现软开关动作、输出电流纹波小以及控制简单等优点。详细分析了该变换器的稳态工作原理以及实现软开关的条件,并通过仿真和实验对上述分析进行了验证。     

谐振复位双开关正激变换器的研究

推荐了一种谐振复位双开关正激型DC／DC变换器。它不仅克服了谐振复位单开关正激变换器开关电压应力大和变换效率低的缺点，而且具有占空比可以大于50％的优点。因此，该变换器可以应用于高输入电压、宽变化范围、高效率要求的场合。对该拓扑的工作原理和特性进行了详细的描述。最后通过实验证实了该拓扑的上述优点。     

低输出电压纹波三态PCCM CUK PFC变换器

提出了一种具有低输出电压纹波的三态伪连续导电模式(PCCM)CUK功率因数校正(PFC)变换器及其控制策略。在CUK变换器的中间储能电容(过渡电容)上串联一个开关管,使得中间储能电容电压在一个开关周期内存在3个工作状态,进而获得低输出电压纹波和快速的负载动态响应速度。分析了三态PCCM CUK PFC变换器的工作原理,仿真验证了理论分析结果,同时通过一个200 W的实验电路验证了结论的正确性。结果表明三态PCCM CUK PFC变换器具有输入功率因数高、输出电压纹波小和动态响应速度快的优点。     

Boost型三电平AC/AC变换器

针对高输出交流电压的升压场合,研究Boost型三电平AC/AC变换器。相比于Boost型两电平AC/AC变换器,该变换器通过增加开关管数量和引进飞跨电容,构造了中间电平,可使开关管的电压应力降低一半,滤波器重量体积大大减小。其拓扑可以看成是两个输出电压极性相反的Boost型三电平DC/DC变换器组合而成,该变换器输入输出电压同相位,其飞跨电容电压等于输出电压的一半。详细分析其电路工作原理,给出一种新颖的控制策略,可对输出电压和飞跨电容电压同时进行控制;研制一台原理样机,给出了实验波形与测量结果。实验结果证实了理论分析的正确性和控制策略的可行性。     

具有宽负载范围和低电压应力的三态反激PFC变换器

提出一种具有宽负载范围和低电压应力的三态反激功率因数校正(PFC)变换器拓扑。通过续流功率开关管和二极管,使该变换器工作于伪连续导电模式(PCCM),拓宽了传统不连续导电模式(DCM)反激PFC变换器的带载能力,并有效地降低了传统DCM反激PFC变换器中功率开关管所承受的电压应力。通过对电路工作模态及其稳态特性的分析可知,该变换器不仅具有较好的功率因数校正能力,还具有开关管电压应力低、负载范围宽等优点。最后,通过实验结果验证了该变换器的优越性。     

准单级功率变换的高效单相三端口功率因数校正变换器

由于Boost型功率因数校正(PFC)变换器输出电压必须高于交流电压峰值,因此当负载电压较低时,其需要级联直流/直流(DC/DC)变换器,不利于系统效率提高。以优化PFC变换器随电网电压变化的瞬时效率、进而提升整体效率为目标,研究了一种单相三端口PFC变换器。通过将传统三电平Boost变换器的低压侧分压电容直接用作负载输出端口,并构造出一个高压端口,可以实现交流输入侧和直流负载侧之间的准单级功率变换,有效减小了系统中功率变换的级数,从而实现PFC变换器整体效率的提升。此外,准单级功率变换的特性还有利于减小后级DC/DC变换器的电压电流应力和功率损耗,进一步提高交流/直流(AC/DC)变换器的整体效率。文中详细分析了三端口PFC变换器的工作原理和控制策略,建立了损耗分析模型并进行了仿真验证。最后,利用2kW实验样机验证了所研究变换器在改善系统效率方面的有效性。     

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     

四相开关磁阻电机新型T型功率变换器研究

为了扩大四相开关磁阻电机(SRM)驱动系统的输出功率范围,提出了一种新型不对称T型功率变换器。该功率变换器由改进的T型功率变换器和辅助电路构成:T型变换器为多电平电路,可使得电机绕组在多种模式下工作,控制灵活;辅助电路能够使直流侧分压电容在实现直流侧电压钳位的同时用作电机相电流上升及下降期间的电压抬升。对电机不同运行模式进行了详细分析,并对比了所提T型功率变换器与二极管中性点钳位(NPC)功率变换器的效率及成本。对SRM系统进行了仿真研究,结果表明所提新型T型功率变换器可提升SRM系统的转速及功率输出能力,提高系统整体效率,适用于电机高速运行场合。     

含恒功率负荷直流微电网的状态反馈电压振荡控制技术

扰动发生后新能源发电和恒功率负荷侧换流器在现有功率控制模式下所表现出的负阻抗特性,会大幅增加直流电压振荡失稳的风险.为此,首先针对直流电压振荡失稳的问题,推导含恒功率负荷两端直流微电网的小扰动线性化状态方程.其次,结合各状态变量的参与因子,选取振荡电流、电压作为可调节控制参数,将其分别引入储能换流器与恒功率负荷换流器的占空比反馈环节中,提出基于状态反馈的多端直流电压振荡控制方法.然后,利用根轨迹、Bode图分析附加状态反馈电压振荡控制技术后的直流微电网稳定裕度的变化规律,为控制参数设计提供依据.最后,搭建时域仿真系统,验证了所提出的控制方法可有效抑制直流微电网的电压振荡,显著提高系统的动态稳定性.     

A New High Step-Up DC/DC Converter Structure by Using Coupled Inductor with Reduced Switch-Voltage Stress

In this paper, a new high step-up DC/DC converter for renewable energy systems is proposed, which provides high voltage gain by using a coupled inductor without having to have high-duty cycle and high-turn ratio. Moreover, the voltage gain increased by using capacitors charging techniques. In the proposed converter, the energy of leakage inductors of the coupled inductor is recycled to the load. This feature not only reduces stress on main switch but also increases the converter efficiency. Also, due to the configuration of the proposed structure, the voltage stress on the main switch is significantly reduced. Since the stress is low in this topology, low voltage switch with small ON-state resistance value can be used to reduce the conduction losses. As a result, losses decrease and the efficiency increases. Meanwhile, the main switch is placed in series with the source and it can control the flow of energy from source to load. The operating principles and steady-state analysis of the proposed converter are discussed in details. Finally, the prototype circuit with 12 V input voltage, 300 V output voltage, and 60 W output power is operated to verify its performance.     

Series resonant high‐voltage DC–DC converter with reduced component count

This paper proposes a novel zero‐current‐switching series resonant high‐voltage DC–DC converter with reduced component count. The series resonant inverter in the proposed topology has two power switches (insulated‐gate bipolar transistors, IGBTs), two resonant capacitors, and only one high‐voltage transformer (HVT) 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 the resonant capacitors form two series resonant circuits. The series resonant circuits are fed alternately by operating the power switches with interleaved half switching cycle. The secondary winding of the HVT is connected to a bridge rectifier circuit to rectify the secondary voltage. The converter operates in the discontinuous conduction mode (DCM) 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 its lower core loss, lower cost, and smaller size compared to previously proposed double series resonant high voltage DC–DC converters. The experimental results of a 130‐W prototype of the proposed converter are presented. The results confirm the excellent operation and performance of the converter. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于脉冲宽度调制控制策略的零电流开关高功率因数AC/DC变换器

目前，对单级功率因素校正电路的研究大多集中在小功率应用领域，为此该文提出一种能够应用于中大功率场合、实现了零电流开关的单级高功率因数AC／DC变换器拓扑。通过在全桥变换器中增加辅助开关实现了PWM控制，它不仅能够在很宽的负载范围内实现零电流开关和功率因数校正，而且解决了全桥谐振电路中。在不采用移相控制的情况下，必须采用PWM控制策略的问题。与2级式功率因数校正电路相比，提高了动态响应的速度、降低了成本，并且开关管的电压应力较低。仿真和实验分析验证了变换器的优越性。     

A single‐stage integrated bridgeless AC/DC converter for electrolytic capacitor‐less LED lighting applications

In this paper, a single‐stage integrated bridgeless AC/DC converter is proposed. As compared to its counterpart that is composed of totem‐pole boost power factor correction (PFC) cascade fly‐back DC/DC converter, the studied circuit has less components number while overcoming the limits of the totem‐pole type. Thus, it is suitable to the low‐power LED lighting applications. Furthermore, when both PFC inductors L_b and magmatic inductance L_m of the transformer TR1 operate at discontinuous current mode, the bus voltage v_CB can be used to decouple the ac input and constant dc output power. Thus, the approach of increasing bus voltage ripple is employed to eliminate electrolytic capacitors and obtain long operation lifetime. Additionally, it is able to be compatible with our studied twin‐bus configuration for increasing the overall efficiency. A 50‐W hardware prototype has been designed, fabricated, and tested in the laboratory to verify the proposed converter validity. Copyright © 2014 John Wiley & Sons, Ltd.     

高效双向DC/DC变换器

通过分析DC/DC变换器的工作方式,总结出一种应用于串联超级电容器组单体电压动态均衡电路的变换器——高效双向推挽DC/DC变换器,并选择了合适的控制芯片和驱动方式。该方案具有电路拓扑简洁、双向功率流动、控制简单、变换效率高、可靠性高等优点。