移相全桥DC/DC变换器的设计

针对全桥移相软开关变换器存在滞后桥臂难以实现ZVS,提出了一种新型的全桥移相ZVS变换器拓扑结构。论述了所提出拓扑结构的工作原理、工作过程,对主要器件进行了参数选择,根据所选取参数对主电路进行研究,给出了主要波形,实验结果验证了电路分析的正确性和设计的可行性。     

用PWM芯片实现全桥移相ZVS隔离DC／DC变换器的研究

简述了市场上现有移相控制器的简单情况,分析了全桥移相的工作原理,进而介绍了采用常规PWM控制芯片及全桥驱动器HIP4081A实现50w／500kHz全桥移相ZVS隔离DC／DC变换器,通过有效的利用变压器漏感、MOSFET的输出电感以及MOSFET的体二极管实现ZVS,大幅度降低了开关损耗、热损耗、EMI和RFI。通过深入细致的实验观察,验证了理论设计的正确性、合理性,并给出了相关的实验波形和实验结果分析。     

ZVZCS移相全桥PWM变换器的分析与仿真研究

ZVZCS移相全桥PWM变换器实现了超前桥臂的零电压开关(ZVS)与滞后桥臂的零电流开关(ZCS),其软开关的实现条件比ZVS移相全桥与ZCS移相全桥要好。文章全面分析了这种变换器的工作原理,讨论了实现软开关的条件,设计关键参数并利用SIMetrix软件进行了仿真研究。     

ZVZCS移相全桥PWM变换器的设计与仿真

ZVZCS移相全桥PWM变换器实现了超前桥臂零电压开关(ZVS)和滞后桥臂零电流开关(ZCS),具有结构简单、占空比丢失较小、软开关较容易实现等特点。文章全面分析了该变换器的工作原理、讨论实现软开关的条件,设计了主要参数,然后利用SIMetrix仿真软件对电路进行仿真,通过波形验证了参数设计合理、变换器实现ZVZCS。     

移相全桥DC/DC变换器ZVS控制的研究与实现

在中大功率应用场合,零电压开关控制的移相全桥PWM DC/DC变换器近年来受到越来越多的关注,并被广泛地应用于工程中,其可靠性越来越受到人们的重视。文章详细介绍了这种变换器的ZVS控制原理及其实现中存在的主要问题,利用电源仿真软件SIMetrix对变换器进行了仿真,最后根据仿真参数结果设计了移相控制零电压开关PWMDC/DC全桥变换器样机,验证了该研究的正确性。     

PS—FB—ZVSPWM DC／DC变换器中副边占空比丢失问题的研究

移相控制ZVSPWM DC／DC全桥变换器是变换器的一个研究热点,诸如高性能、高效率、低噪声、低污染等理论问题急待研究。副边占空比丢失是移相全桥PWM DC／DC变换器中的一个重要现象,文章以移相全桥ZVSPWM DC／IX;变换器电路模型为基础,结合变换器谐振电路的工作特点,对变换器副边占空比丢失的原因进行了详尽的分析,阐述了全桥变换器滞后臂比超前臂更难实现ZVS的原因,最终得到了移相全桥ZVSPWM DC／DC变换器死区时间和工作频率的设置条件与解决副边占空比丢失的措施。     

一种车载DC/DC变换器的研制

由于车载DC/DC变换器的特殊应用环境,要求其具有小体积、大功率、高效率、高抗震的特点。文章研究了一种车载DC/DC变换器,该变换器采用全桥移相ZVS PWM控制和倍流整流技术,能较好地满足车载大功率DC/DC变换器的各种性能指标。文中分析了该变换器的工作原理,给出了实验结果和波形。     

带有箝位二极管的ZVS全桥三电平DC/DC变换器的研究

介绍了一种改进型的带有箝位二极管的零电压开关(ZVS)全桥三电平DC/DC变换器,详细分析了电路的工作原理。设计实例和仿真结果验证了理论分析的正确性。     

整流器、电源电路

介绍了改良型零电压开关(ZVS)逆向变换器拓扑。这种变换器利用一个辅助电路为主和辅助开关提供 ZVS,并允许变换器以甚高频工作。叙述了该变换器辅助电路的操作原理、稳态分析和设计过程。构成了50W 200kHz 原理变换器,以验证其性能。试验结果表明,与以往的 ZVS 逆向变换器相比,总效率提高约2%。参6     

改进型脉宽调制DC/DC变换芯片的实现

提出了一种改进型的脉宽调制DC/DC变换器的电路结构,该电路具有结构简单、功耗低、转换效率高等特点.根据F0UNDRY提供的模型参数,用EDA工具对芯片主要电路和整个电源系统进行了模拟,给出了模拟结果.采用3μmP阱双层多晶、单层金属CMOS工艺制造芯片.     

A 1-MHz Zero-Voltage-Switching Asymmetrical Half-Bridge DC/DC Converter: Analysis and Design

The asymmetrical half-bridge (AHB) topology discussed in this paper is one of the complementary driven pulse-width modulated converter topologies, which presents an inherent zero-voltage switching (ZVS) capability. In the previous work, the ideal operation of the converter and the ZVS realization process have been analyzed. However, the influence of the circuit parasitics on the output voltage drop and the design constraints of the circuit parameters to ensure the ZVS operation have not been investigated. The minimum load needed to ensure the ZVS operation is also not readily available. This paper presents a detailed and practical design for a 1-MHz AHB converter. A revised voltage transfer ratio of the converter is derived considering the influence of circuit parasitics and the ZVS transition. Two circuit parameters responsible for maintaining the ZVS operation are the transformer leakage inductance and the interlock delay time between the gate signals of two switches. A design method of the two parameters is proposed, which can ensure the ZVS transition. The possible ZVS range of the load variation is also investigated. A 50-W AHB converter with 1-MHz switching frequency was constructed, and a maximum efficiency of 91% was achieved.     

A zero-voltage and zero-current switching three-level DC/DC converter

This paper presents a novel zero-voltage and zero-current switching (ZVZCS) three-level DC/DC converter. This converter overcomes the drawbacks presented by the conventional zero-voltage switching (ZVS) three-level converter, such as high circulating energy, severe parasitic ringing on the rectifier diodes, and limited ZVS load range for the inner switches. The converter presented in this paper uses a phase-shift control with a flying capacitor in the primary side to achieve ZVS for the outer switches. Additionally, the converter uses an auxiliary circuit to reset the primary current during the freewheeling stage to achieve zero-current switching (ZCS) for the inner switches. The principle of operation and the DC characteristics of the new converter are analyzed and verified on a 6 kW, 100 kHz experimental prototype.     

Analysis and design considerations of a load and line independent zero voltage switching full bridge DC/DC converter topology

The analysis and design of a zero voltage switching (ZVS) full bridge DC/DC power converter topology is presented in this paper. The converter topology presented here employs an asymmetrical auxiliary circuit consisting of a few passive components. With this auxiliary circuit, the full bridge converter can achieve ZVS independent of line and load conditions. The operating principle of the circuit is demonstrated, and the steady state analysis is performed. Based on the analysis, a criterion for optimal design is given. Experiment and simulation on a 350-400 V to 55 V, 500 W prototype converter operated at 100 kHz verify the design and show an overall efficiency of greater than 97% at full load.     

不对称半桥变换器的小信号建模与仿真研究

不对称半桥变换器利用自身的寄生器件实现了开关管的零电压操作,在不影响电路整体结构,以及不增加成本的前提下达到了很好的输入、输出特性。文章建立了该类变换器的小信号模型,进行了动态分析、仿真研究及补偿回路设计,并对整体的电路稳定性和几个关键的频率特性进行了研究。     

Quasi-parallel resonant DC link inverter with improved PWMcapability

A quasi-parallel resonant DC-link (QPRDCL) circuit with improved PWM capability is proposed for the zero voltage switching (ZVS) three phase PWM inverter. The circuit has minimum voltage stresses and improved PWM capability due to the flexible selectability of the on/off instants of the resonant link     

一种带辅助电路的全桥移相ZVS变换器拓扑的设计

许多结构诸如添加饱和电感、在滞后臂并联由电感和开关管组成的辅助电路、副边采用倍流整流电路等被用来拓宽传统全桥ZVS拓扑实现零电压开关的负载范围,减小占空比的丢失,但这些方法往往成本高,设计难度大.我们以低成本,设计简单同时又能满足系统性能为出发点给出了一种带简单的LC辅助谐振电路的变换器拓扑.论文阐述了该变换器的基本工作原理,分析了占空比的丢失和实现ZVS的范围.在设计中通过折中考虑各个元件参数使得系统获得最佳性能,并给出了一个1.2 kW变换器的设计实例来说明如何找到系统的最佳参数.     

A modified asymmetrical pulse-width-Modulated resonant DC/DC converter topology

A modified asymmetrical pulse-width-modulated resonant dc/dc converter employing an auxiliary circuit will be proposed in this paper. The auxiliary circuit consists of a network of two capacitors and an inductor. The aim of this network is to produce zero-voltage-switching (ZVS) over a wide input voltage range, while reducing the voltage stress on the resonant component. A detailed analysis and performance characteristics are presented. Experimental results for a 5 V, 35 W converter show an efficiency of 83% at a constant operating frequency of 500 kHz. Using metal oxide semiconductor field effect transistors (MOSFETs) as synchronous rectifiers can further reduce power losses and improve the efficiency to be greater than 90%.     

一种移相全桥DC/DC变换器的设计

设计了一种DSP控制移相全桥ZVS软开关式DC/DC升压变换器。主变换电路使用了移相全桥设计,能较好地实现零电压通断,且转换效率明显提高。控制电路采用DSP处理器控制,能有效地进行实时校正,获得稳定输出,同时由于软件控制调整移相角α,可实现直流输出的宽范围调整,具有较高的工程应用价值。