交错临界导电模式PFC原理与设计

文中介绍了交错CRM—PFC的基本原理和基于R2A20112控制器的交错CRM—PFC变换器的设计。临界导电模式（CRM）是一种功率因数校正（PFC）控制方法。交错CRM—PFC允许升压变换器获得180°的相位移和在CRM操作,可使输入和输出电容器上的纹波电流大大地减小。     

Buck-Boost变换器的能量传输模式及输出纹波电压分析

根据电感电流最小值与输出电流的比较,将Buck-Boost 变换器的能量传输模式(ETM)分为完全电感供能模式(CISM)和不完全电感供能模式(IISM),得出了CISM和IISM的临界条件和临界电感.将电感电流最小值与零和输出电流进行比较,得出Buck-Boost 变换器存在三种工作模式,即CISM、不完全电感供能且连续导电模式(IISM-CCM)和不完全电感供能且不连续导电模式(IISM-DCM).推导出了变换器工作于三种模式时的输出纹波电压表示式,指出对于给定负载、电容和开关频率的Buck-Boost变换器,CISM的输出纹波电压最小且与电感无关,而IISM-CCM和IISM-DCM的输出纹波电压较大且随电感减小而增大.CISM和IISM的临界电感即为使得变换器的输出纹波电压最低的最小电感.文中给出实例,实验结果与理论分析一致,但因未考虑器件参数输出纹波电压略高于理论分析值,实验结果验证了理论分析的正确性.     

基于R2A20114SP的功率因数校正电路

介绍一种交互式新型的功率因数校正电路(PFC),该电路以R2A20114SP芯片为控制核心,采用Boost升压电路,整合了临界导通模式(CRM)交错PFC控制技术,同时根据芯片特点设计了匹配的MOSFET驱动电路.实验表明:电路保证了输入电流波形为正弦,输入电流谐波足以满足IEC100032的要求;PFC级的电流能自动跟随输入电压,提高了功率因数(PF)值.     

基于UCC28061的交错并联BCM Boost PFC设计

采用UCC28061设计了一款工作在交错并联临界模式下300W的电源。交错并联的Boost PFC拓扑结构,能够大大减小输入电流纹波和输出电容电流纹波。实验结果表明,AC85-265V输入时,功率在300W时PF能够达到0.99以上,电流畸变率THD在3%以下。     

一种新颖的PFC控制策略

分析设计了一款新颖的功率因数校正(PFC)电路,该电路可以工作于不连续传导模式(DCM)和临界连续传导模式(CRM),并实现两种模式的自动切换,兼具两种工作模式的优势。在输入电压跨零附近,电路工作于固定频率的DCM下,限制最大的开关频率,从而降低污染系统的电磁干扰(EMI)噪声。在输入电压峰值附近,电路工作于频率可变的CRM下,降低升压二极管、功率MOSFET和电感上的电流应力,从而降低费用并且提高电路的可靠性。采用台联电0.6μmBCD工艺仿真验证,得到了近1的功率因数。     

一种Boost型PFC电路在DCM下的恒频控制方案

通过对Boost型变换器在不连续导电模式DCM(Discontinued Conduction Mode)下平均电感电流的分析,得到了在恒 频状态下实现功率因数校正 PFC ( Power Factor Correction)时,功率开关管所需的开启时间与输入、输出电压之间的数学关系,并结合实际电路设计,提出了一种PF...     

四级交错单相有源功率因数校正器的研究

在家用变频空调等应用中,功率因数校正器(PFC)的功率等级越来越大。多级交错PFC可以有效地降低电源纹波电流,简化电感设计和提升系统效率。文中在描述这种PFC单周期控制原理基础上,提出了一种基于IGBT电流的电流合成方法,分析了四级交错并联PFC中IGBT占空比与纹波电流关系、输出滤波电容纹波电流和开关频率调制原理,并采用Matlab/Simulink进行了全面的仿真分析。为验证理论分析和仿真分析,基于RENESAS最新推出的模拟控制器R2A20104,设计和实现了额定输出功率8.0kW的四级交错PFC。结果表明,采用单周期控制、电流合成原理实现并联交错有源PFC是可行的,具有很好的输入端纹波电流抑制效果,且电感设计简化,并能提升系统效率。     

升压型PFC调制器的低谐波失真设计

本文基于临界导通模式下的升压型PFC调制器,实现一种新颖的固定开启时间控制方式。控制方法通过补偿输入电容造成的输入电压和输入电流之间的相移,提高升压型PFC调制器的功率因数,有效抑制调制器的谐波失真。采用TSMC制程,实现100W升压型PFC调制器,在交流输入264V电压下测试总谐波失真为4.7%。     

临界导电交错模式PFC控制R2A20112原理及应用

R2A20112是一种交错双相临界导电模式PFC控制器.交错功能利用180°的相位移减小了输入和输出电容器上的纹波电流.介绍RA20112的特点、引脚功能、工作原理及应用电路.     

AOS推出功率因数校正（PFC）功率因数校正ICAOZ7111

日前,AOS万国半导体发布了第一款新产品系列的功率因数校正（PFC）IC;AOZ7111是一个有源功率因数校正控制器,它集成了各种各样的安全保护功能,具备高性价比的离线式电源转换解决方案。AOZ7111,非常适合PFC应用程序运行在临界导电模式（CRM）。     

开关电容boost—buck功率因数校正组合开关变换器

文章提出了一种基于开关电容网络的boost-buck组合开关变换器,当其输入环节工作在不连续导电模式（DCM）时,具有功率因数校正（PFC）功能,详细分析了这类变换器的工作原理、临界条件、输入输出电压变比以及各器件的应力。实验结果与理论分析相符。     

电子镇流器中功率因数校正电路的分析及应用

IR2166/IR2167是集功率因数校正器(PFC)、镇流器和半桥驱动器为一体的新型电子镇流器驱动电路.内部的功率因数校正(PFC)电路以临界导通模式(CCM)工作,可获得高功率因数、低总谐波失真(THD)及直流电压调整.给出典型PFC控制电路的原理并进行了分析.     

新颖的含PFC的PWM ZVS AC-DC变换器

提出了一种新的具有功率因数补偿(PFC)功能的零电压开关(ZVS)AC-DC变换器,该变换器基于不连续导电模式(DCM)下的Boost环节实现PFC功能,但其具有ZVS机制,从而解决了DCM下因开关关断大的峰值电流引起的关断损耗高、EMI严重的问题,同时还消除了由于开关的寄生电容引起的开通损耗.该变换器可以采用通用控制芯片并工作在PWM模式.文中分析了提出变换器的工作原理,并给出了基本设计原则.模拟和实验结果证明了提出的电路是可行的.     

Voltage and current stress reduction in single-stage power factorcorrection AC/DC converters with bulk capacitor voltage feedback

Single-stage power factor correction (PFC) AC/DC converters integrate a boost-derived input current shaper (ICS) with a flyback or forward DC/DC converter in one single stage. The ICS can be operated in either discontinuous current mode (DCM) or continuous current mode (CCM), while the flyback or forward DC/DC converter is operated in CCM. Almost all single-stage PFC AC/DC converters suffer from high bulk capacitor voltage stress and extra switch current stress. The bulk capacitor voltage feedback with a coupled winding structure is widely used to reduce both the voltage and current stresses in practical single-stage PFC AC/DC converters. This paper presents a detailed analysis of the bulk capacitor voltage feedback, including the relationship between bulk capacitor voltage, input current harmonics, voltage feedback ratio, and load condition. The maximum bulk capacitor voltage appears when the DC/DC converter operates at the boundary between CCM and DCM. This paper also reveals that only the voltage feedback ratio determines the input current harmonics under DCM ICS and CCM DC/DC operation. The theoretical prediction of the bulk capacitor voltage as well as the predicted input harmonic contents is verified experimentally on a 60 W AC/DC converter with universal-line input     

Digitally controlled boost power-factor-correction converters operating in both continuous and discontinuous conduction mode

Whereas power-factor-correction (PFC) converters for low-power ranges (less than 250 W) are commonly designed for operation in the discontinuous conduction mode, converters for higher power levels are operated in the continuous conduction mode. Nevertheless, when these converters are operated at reduced power, discontinuous conduction mode will appear during parts of the line period, yielding input current distortion. This distortion can be eliminated by employing a dedicated control algorithm, consisting of sample correction and duty-ratio feedforward. The reduction of the harmonic distortion of the input current and the increase of the power factor are demonstrated by experiments on a 1-kW boost PFC converter.     

基于Zeta变换器的单相功率因子校正电路

分析了基于Ｚｅｔａ变换器的功率因子校正（ＰＦＣ）电路；研究了工作在不连续导电模式的Ｚｅｔａ变换器实现功率因子校正的机理；推导出了保证电路实现功率因子接近１的临界电感值。ＳＰＩＣＥ仿真和实验结果都证明了理论分析是正确的，为设计功率因子校正的Ｚｅｔａ变换器提供了理论依据。     

A ZCT auxiliary commutation circuit for interleaved boost converters operating in critical conduction mode

This paper investigates a power-factor-corrector (PFC) circuit based on interleaved boost converters in critical conduction mode (C-DCM) with a zero current transition (ZCT) circuit. By using the interleaved converters technique, the input current ripple is minimized, and due to the operation in C-DCM, the main switches turn-on occurs naturally under zero current and the reverse recovery losses of the diodes are minimized. The use of auxiliary commutation circuits provides ZCT at main switches turn-off, minimizing the related turn-off losses. The command circuit of the converters has been implemented by using a single erasable programmable logic device (EPLD) EPM7128SLC84-15. Operating principles, theoretical analysis, design guidelines and a design example are described and verified experimentally by a 1.2 kW prototype. Finally, the measured losses in the PFC interleaved boost converters with and without the proposed ZCT commutation cell, as well as a previously published ZCT cell are presented and discussed.     

一种临界导电模式的功率因数校正电路

使用有源功率因数校正技术可有效抑制电网电流谐波和提高开关电源功率因数。文中分析了临界导电模式Boost型功率因数校正电路的电路结构及其工作原理,应用反馈控制理论,研究了功率因数校正环节的控制特性,给出了其电路参数的设计方法,保证在电网电压和负载功率大范围变化时,功率因数维持在0.99 以上。     

Fast-scale instability of single-stage power-factor-correction power supplies

This paper describes the fast-scale bifurcation phenomena of a single-stage power-factor-correction (PFC) power supply which is a cost effective design for low-power applications. The circuit employs a cascade configuration of a boost converter and a forward converter, which share an active switch and operate in discontinuous conduction mode, to provide input PFC and tight output regulation. Main results are illustrated by "exact" circuit simulations as well as theoretical analysis based on the use of Jacobians. This work provides a convenient means of predicting stability boundaries which can facilitate the selection of practical parameter values for maintaining stable operation.