一种基于辅助网络的软开关二次型Boost高增益变换器

在基于减少冗余功率(R~2P~2)原理的二次型Boost变换器基础上,通过引入辅助网络单元,提出一种基于辅助网络的软开关二次型Boost高增益变换器。该变换器在减少功率传输损耗的同时,实现了全部开关管的零电压导通(ZVS)和输出二极管的零电流关断(ZCS),降低了开关器件的开关损耗。辅助网络与二次型Boost变换器输出串联,提高了变换器电压增益,减小了开关管电压应力。因此,可选取低电压等级、低导通电阻的MOSFET管,进一步提高变换器的效率,降低成本。研究变换器的工作原理和工作特性,分析开关管ZVS条件和占空比丢失问题,设计了一台100W的实验样机,实验结果验证了理论分析的正确性。     

新型高效高增益Boost变换器的研究

随着光伏、燃料电池等绿色能源的不断应用与发展,高增益Boost变换器得到广泛研究和应用。提出一种新型高增益Boost变换器,在传统Boost变换器基础上引入电压举升电路、开关电感、开关电容3个小单元得到,以较小的占空比获得了较大的电压增益,进一步提高了变换器升压能力。同时,该新型变换器克服了传统Boost变换器开关管和二极管电压、电流应力过大的缺点,降低了功率元器件功率损耗,减小了开关管导通损耗及二极管反向恢复损耗。理论分析了该变换器的工作原理及工作特性,在理论研究基础上进行仿真并搭建了一台实验样机,实验结果证明了理论分析的正确性。     

双耦合电感二次型高升压增益DC-DC变换器

提出一种双耦合电感单开关二次型高增益变换器。在传统单开关二次型Boost变换器拓扑的基础上,在前级Boost电路单元引入耦合电感,输出端叠加以提升变换器的升压增益特性;同时,通过在后级Boost电路单元引入耦合电感,进一步减小开关管的电压应力。此外,采用无源无损吸收电路抑制了开关管两端的电压尖峰,从而可选取低导通电阻、低电压等级的MOSFET以降低开关管的导通损耗,提高了变换器的效率。文中详细分析了变换器的工作原理及工作特性,最后通过搭建一台200W、18V/200V的实验样机,验证了理论分析的正确性。     

基于耦合电感倍压单元的零输入电流纹波高增益非隔离变换器

提出一种基于耦合电感倍压单元的零输入电流纹波非隔离型高增益DC-DC变换器。该变换器由零输入电流纹波Boost变换器和耦合电感单元组成,通过设计耦合电感电压比,实现了高升压增益特性。同时,采用无源无损吸收电路消除了漏感引起的开关管两端电压尖峰,降低了开关管的电压应力。通过增加由电容和二极管组成的倍压单元,进一步减小了开关管的电压应力,同时消除了输出二极管的电压尖峰,降低了二极管电压应力。因此,可通过选取低导通电阻、低电压等级的MOSFET,以降低变换器成本和开关管的导通损耗,提高变换器的效率。此外,还实现了变换器的零输入电流纹波,降低了输入滤波器的设计难度。文中详细分析了该变换器的工作原理及工作特性,给出了关键参数的设计原则。最后,通过实验结果验证了理论分析的正确性。     

一种低输入纹波电流的高增益软开关Boost变换器

针对新能源应用系统中输出电压低的问题,提出一种低输入纹波电流的高增益软开关Boost变换器。该变换器通过在二次型Boost电路的基础上加入耦合电感和倍压电路来提高增益。理论分析与实验结果表明该变换器具有高增益的同时还具有以下优点:1)输入电流为Boost电感电流,相对于耦合电感型变换器来说,其纹波得到大幅降低;2)所有开关管均实现了软开关,降低了开关损耗;3)由于漏感的作用,倍压电路中的二极管反向恢复损耗几乎为0;4)所有元器件的电压应力均低于输出电压,可采用低耐压元器件来降低导通损耗;5)耦合电感在开关导通和关断期间均传递了能量,提高了利用率,从而可提高功率密度。     

具有开关电容单元的电感集成Boost变换器

为提高传统Boost变换器的电压增益,降低开关管电压应力,减小变换器损耗,将开关电容和开关电感应用在传统Boost变换器中,提出一种具有开关电容单元的电感集成Boost变换器。利用开关电感与开关电容替代传统Boost变换器中的储能电感与滤波电容,并对开关电感进行了耦合集成。分析了变换器的工作模态,推导得到了变换器电压增益表达式,并研究了电感串联等效电阻对变换器电压增益的影响;分析了开关管电压应力与电感电流纹波的大小。与传统Boost变换器相比,具有开关电容单元的电感集成Boost变换器的电压增益增加一倍,开关管电压应力减小了一半,电流纹波减小接近1/2。样机实验结果验证了理论分析的正确性,表明具有开关电容单元的电感集成Boost变换器具有优良的综合性能。     

新型单开关高增益Boost变换器研究

提出了一种基于电压举升技术(voltage-lift-technique)的新型单开关高增益Boost变换器,不但拓宽了Boost变换器输入电压范围,而且降低了开关管的电压应力,适用于输入电压变化范围较宽的应用场合.与二次型Boost变换器相比,该新型Boost变换器的开关管电压应力低,便于选取导通电阻较小的功率开关管,从而减小开关管的导通损耗,提高变换器的效率.本文分析了该新型高增益Boost变换器的工作原理,研究了电路参数对其稳态工作特性的影响.最后通过仿真及实验验证了理论分析的正确性.     

新型高增益DC/DC升压变换器的研究

随着燃料电池、光伏发电、超级电容混合系统等新能源发电系统逐渐受到人们的重视,高增益、高效率、低器件应力的DC/DC变换器得到了广泛的研究与应用。此处在Buck-Boost和Boost级联变换器基础上引入开关电容技术设计了新型高增益低应力DC/DC升压变换器。首先分析了新型高增益低应力DC/DC升压变换器的工作原理及开关管与电容应力,并与开关电容Boost变换器、传统二次型Boost变换器、Buck-Boost和Boost级联变换器的增益、电容应力,开关管应力等进行比较。分析表明该变换器拥有更高的电压增益以及更低的器件应力。最后在理论分析的基础上进行仿真实验并搭建了一台基于碳化硅(SiC)功率器件的实验样机,对理论分析的正确性和可靠性进行了验证。     

高效率的BOOST型功率因数校正预调节器

有源功率因数校正(PFC)通常采用Boost变换器，在低压90V输入时，其输出电压调节在380V，此时变换器效率最低。该文提出一种变输出电压的控制方式，其输出电压随着输入电压的变化而变化。这种方法可以缩短开关管的导通时间，减小流经开关管的电流有效值，从而降低其导通损耗，提高变换器的效率。分析了Boost PFC变换器的损耗分布和控制方法。最后在一台1200W的原理样机上进行实验验证，还对比快恢复二极管和SiC二极管的关断特性，给出实验结果。     

基于LC吸收电路的耦合电感倍压单元高升压增益Boost变换器

提出一种基于LC吸收单元的耦合电感倍压单元高增益Boost变换器。在Boost变换器中引入耦合电感倍压单元,通过调节耦合电感变比,可实现Boost变换器的高升压增益特性。同时,引入LC吸收电路网络,回收了漏感能量,抑制了开关管两端的电压尖峰,从而可通过选取低导通电阻、低电压等级的MOSFET,以降低变换器成本和开关管的导通损耗,提高变换器的效率。提出的变换器消除了耦合电感的二次侧漏感与输出二极管寄生电容带来的二极管电压尖峰振荡问题,从而减小了二极管的电压应力,进一步改善了变换器的效率。此外,采用LC吸收电路的高增益变换器具有输入电流连续、易实现高升压增益特性的优点,适用于新能源发电领域。详细分析了该变换器的工作原理及工作特性,给出了关键参数的设计原则。最后,通过实验结果验证了理论分析的正确性。     

一种双输入高增益DC-DC变换器

针对光伏发电系统输出电压低、供电稳定性差等问题,提出一种非隔离双输入高增益直流升压变换器,该变换器在2个BOOST变换器的基础上引入了开关电容电路,实现了高电压增益,且两输入源可以单独或同时向负载供电。分析该变换器的电路结构和工作原理,推导出了3种供电模式下变换器的电压增益表达式以及主要开关器件电压应力,给出了两路同时供电时输入电流之间的关系。最后,搭建了一台100W的实验样机,实验验证了该变换器具有电压增益高、开关器件电压应力低、控制简单、可以灵活供电等优点。     

一种新型非隔离型高增益DC-DC变换器

在不间断电源、新能源发电等应用场合中,高增益DC/DC变换器得到了广泛应用。基于两相传统交错并联Boost变换器,提出了一种新型非隔离型高增益DC/DC变换器。所提变换器具有低输入电流纹波、两相电感电流自动均流、开关和二极管电压应力低、升压能力高等特点,适用于输入输出电压比大且无需电气隔离的应用场合。本文首先对所提电路的工作原理进行了具体分析,然后理论推导其主要性能特点,最后通过一台功率为400W的实验样机验证了前述分析的正确性。     

Ultrahigh step-up DC-DC converter consisting quadratic boost converter,multiplier cell,and three windings coupled inductor

This paper presents an ultrahigh step-up converter with combination of a quadratic boost converter, a multiplier cell, and a three windings coupled inductor. Main advantages of the converter include its high voltage gain, low voltage stress on the switch and most of the diodes, continuity of input current with low ripple, and existence of a common ground between the source and load. Furthermore, requiring small inductors leads to high efficiency performance of the converter. To confirm superiority of the proposed converter, it has been compared with the converters consisting coupled inductors. Analysis of the converter has been performed for its main operation modes to validate its quality and quantity factors. A prototype is built in order to experiment its performance per different conditions and evaluate the analysis. Rated values per the experiments are 25, 500, and 200 W for the input voltage, output voltage, and output power, respectively.     

一种高增益交错并联正反激变换器

传统的交错并联boost变换器升压增益很小,电压应力却很高。因此,提出了一种适用于可再生能源系统(光伏系统)的高电压增益变换器,利用电压乘法器模块(由开关电容和耦合电感组成)来提高升压增益的;分析了电路的工作模态,推导了升压增益和电压应力,并计算了传导损耗和效率;比较系统性能后,根据不同的性能指标针对该应用领域进行分析;最后通过实验样机实验证明了理论说法的正确性,结果证明该拓扑结构能够实现高达97.1%的转换效率。     

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.     

Expandable interleaved high voltage gain boost DC-DC converter with low switching stress

In this paper, an interleaved DC-DC step-up boost converter with high voltage conversion ratio and low voltage stresses on switches and diodes is proposed. The proposed converter has low average current passing through the diodes and switches and low input current ripple as a feature of interleaved converters. The voltage gain of the proposed converter can be increased by adding more diode-capacitor modules; therefore, the proposed converter has expandable structure. In addition, by implementing more diode-capacitor modules, the switching stresses would be more decreased. Also, to evaluate the performance of the proposed converter, it is compared with other similar presented circuits in the literature. The proposed converter is not only able to provide higher voltage gain but also has lower voltage stresses on switches and diodes. Consequently, switches and diodes with low voltage ratings can be selected. Theoretical analysis is provided in this study for each operation mode and the average current through the switches, diodes and inductors, voltage stresses on switches and diodes, voltage gain, and input current ripple are calculated. Finally, to demonstrate the accuracy performance of the proposed converter, a 450-W prototype is implemented practically.     

High‐efficiency transformerless buck–boost DC–DC converter

A novel high‐efficiency transformerless buck–boost DC–DC converter is proposed in this paper. The presented converter voltage gain is higher than that of the conventional boost, buck–boost, CUK, SEPIC and ZETA converters, and high voltage gain can be obtained with a suitable duty cycle. The voltage stress across the power switch is low. Hence, the low on‐state resistance of the power switch can be selected to decrease conduction loss of the switch and improve efficiency. The input current ripple in the presented converter is low. The principle of operation and the mathematical analyses of the proposed converter are explained. The validity of the presented converter is verified by the simulation results in PSCAD/EMTDC software and experimental results based on the prototype circuit with 250 W and 40 kHz. Copyright © 2017 John Wiley & Sons, Ltd.     

Boost型无频闪谐振降压式LED驱动电源分析与设计

传统的二次型Boost功率因数校正变换器只能实现升压输出,在一定程度上限制了其在LED驱动电源中的应用。本文基于二次型Boost变换器提出了一种Boost型无频闪谐振降压式LED驱动电源,并分析了其工作原理及特性。该LED驱动电源利用一个有源开关管将二次型Boost变换器与一个谐振网络进行整合。与传统的二次型Boost变换器相类似,该LED驱动电源可以实现高效率和高功率因数。此外,该LED驱动电源可实现低电流纹波和降压变换输出。最后,搭建了一台84W的实验样机,最高效率可达到92.88%,验证了理论分析的正确性及可行性。     

具有高增益的双相直流变换器设计

为了获得较高的电压增益,减小开关管的电压、电流应力,将2个中间储能电容与传统双相BOOST升压电路相结合,研究了一种具有高电压增益的新型双相BOOST电路拓扑。该电路具有以下明显的特点:在相同占空比的情况下能有效提高变换器升压增益,可实现更大的功率变换;主开关管和所增加二极管的电压应力只有输出电压的一半,因此对相同功率级的升压电路,不仅可以选择低耐压、高性能的开关器件,而且可以降低电路的损耗。详细分析了新型双相BOOST变换器的工作原理,制作了1台额定功率为1kW原理样机,通过实验验证了理论分析的正确性和可行性。结果表明,所提出的新型双相BOOST变换器性能优良,结构简单,具有实用价值。