单端初级电感变换器拓扑的LED电源设计

单端初级电感变换器(SEPIC)拓扑结构的转换器既可以实现升压,也可以实现降压,而且转换效率也很高,可作为LED的驱动电源.讨论了LED对驱动电源的要求和SEPIC拓扑的电流连续导通模式(CCM)、临界连续模式(TM)和断续导通模式(DCM)的工作原理,重点论述了TM下的工作机制,并阐述SEPIC拓扑电路的器件参数选择原则.在此基础上设计了SEPIC电路,结合相关的控制芯片,对电路进行PWM和PFC,实验结果证明了分析的正确性.     

基于DPA426R的低压大电流DC/DC变换器

设计了一种基于集成开关电源控制芯片DPA426R的高频DC/DC变换器,输出5V/14A.电路采用单端正激拓扑结构,反馈环路为电压控制模式.针对开关变换器的主要功能模块电路进行了设计和工作原理分析.为了提高开关电源的功率密度,初级控制电路的设计基于高集成度的电源管理芯片DPA426R,输出整流电路采用自驱动同步整流结构...     

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.     

电动汽车用开关磁阻电机集成功率变换器设计

电动汽车用开关磁阻电机控制系统包含电机驱动和电池充电电路,降低了系统集成度和功率密度。以开关磁阻电机不对称半桥式功率变换器为基础,设计了一种用于电动汽车的集成功率变换器,增加了前端电路,通过控制前端电路可以实现电机驱动和电池充电两种工作模式。在电机驱动模式下利用电容器的充放电功能提高了系统的能量比,给出了电容器的容量估算方法,对比了不同容量对系统性能的影响。在电池充电模式下利用电机绕组作为充电电感,对原有功率器件复用,实现了具有功率因数校正（PFC）的功能充电方式,有效地改善了交流信号,分析了电机绕组作为充电电感的限定条件,实现了恒流充电和恒压充电过程,最后通过Matlab/Simulink仿真验证了方案的有效性。     

基于拓扑组合的交错并联耦合电感高增益DC-DC变换器

针对分布式发电系统、航空航天、电动汽车等领域高电压传输比的应用场景,文章提出一种新型交错并联耦合电感高增益DC-DC变换器。所提电路结构采用拓扑组合的形式进行交错并联,一方面扩大了变换器的容量;另一方面降低了输入电流纹波。同时,当匝数比相等时,两相变换器耦合电感处理的功率相等,不存在功率失衡问题。通过集成倍压电容进一步提高了电压增益,降低了功率器件的电压应力,因此可以采用低电压等级、高性能的功率器件来提高变换器的工作效率。采用无源箝位电路吸收并利用耦合电感的漏感能量,降低了开关管的电压尖峰。此外,漏感缓解了二极管的反向恢复问题,提高了变换器的可靠性。详细地分析该变换器的工作原理、稳态性能,并搭建1000W的样机进行验证,实测最高效率为97.2%,满载效率为94.5%,实验结果验证了理论分析的正确性及所提变换器拓扑的可行性。     

全桥升压型高频环节AC/AC变换器

首次提出了全桥升压型高频环节AC/AC变换器电路拓扑,它是由储能电感、输入周波变换器、高频变压器、输出周波变换器以及输入、输出滤波器构成.深入分析研究了这种变换器的稳态原理与移相控制策略,获得了输出电压、储能电感电流、高频变压器匝比、储能电感、输出滤波电容等关键电路参数的设计准则.理论分析结果表明,这种变换器具有高频电气隔离、电路拓扑简洁、两级功率变换(LFAC-HFAC-LFAC)、双向功率流、变换效率高、网侧功率因数高、负载适应能力强、负载短路时可靠性高等优点,为优良性能的正弦交流稳压器、调压器、电力电子变压器和同频波形变换器奠定了关键技术基础.原理实验结果证实了这种变换器的可行性.     

基于临界电流模式的单级DC/AC变换器及其控制

本文提出了一种单级DC/AC开关变换器电路拓扑,给出了相应的控制方案,可作为小功率HID灯的工作电源.它结合了BUCK DC/DC变换器和半桥DC/AC逆变器的特点,BUCK DC/DC变换器工作在高频开关状态用于调节输出功率,半桥逆变器工作在低频状态输出低频方波信号,可有效克服HID灯声共振现象.详细分析了它的工作原理,由于电感工作在临界电流模式,开关管实现零电流接通,提高了效率.与两级电路(DC/DC DC/AC)相比,结构简单、所用器件少、可靠性高.电路仿真和实验结果验证了该方案是可行的.     

电流母线型多输出高压隔离IGBT驱动电源

针对中高压应用场合大量功率电子器件的驱动供电问题,研究了一种电流母线型多输出高压隔离绝缘栅双极型晶体管(IGBT)驱动电源。采用高频电流互感式结构取代传统电压型变压器,通过高压电缆线实现高压隔离,工艺简单;前级全桥串联谐振电路产生高频母线电流,后级稳压模块采用电流输入型Boost变换器,与传统Boost变换器相比,其控制策略简单、易实现自启动;分析了IGBT驱动电路消耗功率估算方法,根据负载功率需求给出后级稳压电路参数设计方法;对后级稳压模块进行损耗分析,提出效率优化方案;最后进行了实验验证。     

三管单级双向电流源高频链逆变拓扑研究

提出了一种单级双向电流源高频链逆变拓扑结构,该逆变器由高频变换器、高频变压器及周波变换器组成。主电路只需要3只功率开关管就能实现DC/AC单级变换和能量双向传输。介绍了电路工作在电感电流断续模式下的工作原理和控制原理,并给出了电路的主要参数设计。实验证明,电路运行可靠,负载适应性好,具有良好的输出特性和双向功率传输的能力。     

电流源高频交流环节AC/AC变换器研究

提出了基于反激F1yback变换器的电流源高频交流环节AC/AC变换器电路结构与拓扑族。该电路结构由输入周波变换器、高频储能式变压器、输出周波变换器以及输入、输出周波变换器构成，能够将一种不稳定畸变的交流电变换成问频率稳定的正弦交流电压；该电路拓扑族包括单四象限功率开关式、推挽式、半桥式、全桥式等四种电路。以单四象限功率开关式电路拓扑为例，分析研究了这类变换器工作模式、稳态原理与电压瞬时值反馈控制策略，给出了变换器的外特性曲线、关键电路参数设计准则。原理试验结果证实了这类变换器新概念的正确性与先进性。     

基于SEPIC变换器的高功率因数LED照明电源设计

针对LED驱动电源功率因数低的问题,依据LED照明电源的特点,选择SEPIC电路作为主电路拓扑实现功率因数校正(PFC)和LED电流控制。传统的SEPIC电路用于功率因数校正时都工作在断续模式下,通过对SEPIC电路的分析,证明了临界连续模式下SEPIC电路也可以实现PFC,并推导出输入输出电压比和功率因数关系的公式,得出当输入输出电压比很小时,功率因数值很高。该电源用单级电路同时实现功率因数校正和LED电流控制,相对两级功率因数校正电路,所用器件少,损耗低,尺寸小,尤其适合空间狭小的照明电源电路。通过实验证明理论分析的正确性。     

两开关伪连续导电模式Buck-Boost功率因数校正变换器

提出两开关伪连续导电模式(pseudo continuous conduction mode,PCCM)Buck-Boost功率因数校正(power factor correction,PFC)变换器及其控制策略。利用两开关PCCM Buck-Boost PFC变换器电感惯性模态所提供的一个额外控制自由度,可实现单位功率因数控制,并明显改善传统单开关Buck-Boost PFC变换器、两开关连续导电模式(continuous conduction mode,CCM)Buck-Boost PFC变换器和两开关不连续导电模式(discontinuous conduction mode,DCM)Buck-Boost PFC变换器的性能。与两开关DCMBuck-Boost PFC变换器相比,两开关PCCM Buck-Boost PFC变换器减小了电感电流纹波。仿真与实验结果表明,两开关PCCM Buck-Boost PFC变换器的负载动态响应速度明显快于传统的两开关CCM和DCM Buck-Boost PFC变换器。     

高频开关电源单端反激变压器的原理与设计方法

针对小功率电源的设计,详细介绍了单端反激变压器中连续电流模式(ContinuousCurrentMode,CCM)和断续电流模式(DiscontinuousCurrentMode,DCM)下变压器的工作原理,论述了采用面积乘积法(AwAe)设计反激式主功率变压器的方法。     

Design considerations of an SEPIC PFC converter for driving multiple lighting LED lamps

This paper presents a single‐ended primary inductance power‐factor‐correction converter (SEPIC PFC) for driving multiple lighting LED lamps. With the aid of this converter, high power factor and high efficiency can be achieved by a simple single‐stage circuit with low device stress features. A burst‐mode dimming method is used to regulate the current and brightness of multiple LED lamps. A laboratory prototype is also built and tested. With the prototype, high power factor can remain under universal input voltage operation and individual lamp brightness control. Copyright © 2008 John Wiley & Sons, Ltd.     

A universal‐input high‐power‐factor power supply without electrolytic capacitor for multiple lighting LED lamps

The AC–DC power supply for LED lighting application requires a long lifetime while maintaining high‐efficiency, high power factor and low cost. However, a typical design uses electrolytic capacitor as storage capacitor, which is not only bulky but also with short life span, thus hampering performance improvement of the entire LED lighting system. In this article, a SEPIC‐derived power factor correction topology is proposed as the first stage for driving multiple lighting LED lamps. Along with a relatively large voltage ripple allowable in a two‐stage design, the proposal of LED lamp driver is able to eliminate the electrolytic capacitor while maintaining high power factor and high efficiency. To further increase the efficiency of LED driver, we introduced and used the twin‐bus buck converter as the second‐stage current regulator with Pulse Width Modulation (PWM) dimming function. The basic operating principle and the deign consideration are discussed in detail. A 50‐W prototype has been built and tested to verify the proposal. Copyright © 2011 John Wiley & Sons, Ltd.     

一种可切换工作模式的反激开关电源

反激变换器存在电感电流连续模式（CCM）和断续模式（DCM）两种工作状态。通常选取处于CCM与DCM的临界状态作为工作点,设计反激开关电源的补偿回路。该折衷方案虽能兼顾两种工作模式,但存在带宽较小、动态响应差的问题,且在轻载情况下尤为突出。针对该问题设计了一种可切换工作模式的反激开关电源,对CCM和DCM模式分别设计环路补偿网络,通过变压器原边电流判断负载情况,进而切换补偿网络,实现电源工作模式的切换。设计了输出功率120 W的反激开关电源样机,进行仿真和样机性能测试,试验结果表明,电源不仅能根据负载情况切换工作模式,而且轻载时具有很好的动态响应,验证了该方案的有效性,与预期设计结果相符。     

窗口控制电流连续模式Boost PFC研究

电流连续模式(CCM)Boost功率因数校正(PFC)电路具有输入功率因数高,结构简单等特点,但BoostPFC也存在轻载或低输入电压时效率下降的问题,针对这一问题,探讨了一种新颖的窗口控制CCM BoostPFC,通过在选定的窗口区域降低开关频率从而降低MOSFET开关损耗,提高电路效率.分析了窗口控制的原理及设计原...     

Input parallel–output parallel connected modular nonisolated DC-DC converters with current self-sharing capability operating in discontinuous conduction mode

This paper covers the self-sharing analysis of dc-dc nonisolated converters with input parallel–output parallel (IPOP) configuration and operating in discontinuous conduction mode (DCM). The main contribution of the proposed system is its capability of providing self-sharing of the currents on both sides of each individual converter, without average current sharing control, even in the face of parametric variations. This self-balance only occurs for DCM. When the addressed converters operate in continuous conduction mode (CCM), the self-sharing does not occur naturally under parametric differences among them, requiring the use of additional control loops. The use of self-sharing converters in nonisolated converters simplifies the control system, it makes the modular solution being attractive for many applications, and it increases the power range that the DCM converters may be applied. This paper brings the theoretical study of self-sharing of the current mechanism to six basic nonisolated converters operating in DCM. The self-sharing is verified by experimental results, which are obtained from three modules of dc-dc SEPIC converters. Both converters were designed to operate with 200-V input voltage, 125-V output voltage, 1500-W rated power (500 W each module), and switching frequency at 30 kHz.     

P-type non-isolated boost DC-DC converter with high voltage gain and extensibility for DC microgrid applications

In this paper, the concept of converter design, using the least number of elements and achieving high voltage gain at the low duty cycle, is proposed for the microgrids. One of the important issues in the microgrids is boosting the low voltage output of sources to the utility voltage level. Therefore, the step-up DC-DC converters are widely used in these systems to attain the utility voltage. The benchmarking of the converters mainly in terms of the voltage gain, efficiency, the number of active and passive components, stresses on semiconductors, and simplicity is considered. In this paper, a new extendable non-isolated boost DC-DC converter is presented. Comparing the conventional boost converter, the basic structure of the proposed converter has a high voltage gain and reduced stress on the switch. To increase the voltage gain, the basic structure of the proposed converter can be easily extended. The modulation technique employed is high-frequency pulse-width modulation (PWM). The detailed analysis of the proposed converter in continuous current mode (CCM) and discontinuous current mode (DCM) is presented. The relations between currents and voltages and the voltage gain in CCM and DCM are obtained. Experimental results are carried out to verify theoretical concepts by using the hardware prototype.