Current-source parallel-resonant DC/AC inverter with transformer

This paper gives the theory and experimental results for a current-source parallel-resonant inverter with a transformer used to change voltage levels and provide isolation. The analysis is performed in the frequency domain using Fourier series techniques to predict output power, efficiency, DC-to-AC voltage transfer function, and component voltage and current stresses. The inverter consists of two switches, a large choke inductor, a transformer, and a parallel-resonant circuit. The magnetizing inductance of the transformer is used as the inductance of the parallel-resonant circuit, thereby requiring one less component. Each switch consists of a MOSFET in series with a diode. The MOSFETs have their sources grounded so there is no need for a complicated gate-drive circuit. An inverter was designed and constructed. The DC input voltage was 156 V and the output voltage was a sine wave with a peak value of 224 V at an operating frequency of 50 kHz. The output power at full load was 100 W     

DC voltage sensorless single-phase PFC converter

We propose a simple DC voltage sensorless single phase PFC converter by detecting an AC line voltage waveform. Both DC voltage and AC current sensors used in the conventional PFC converter are not required to construct the control system. The conventional converter circuit with a boost chopper circuit in the DC side from a rectifier circuit is used as the main PFC converter circuit. In the control system, the circuit parameters such as a series inductance L and equivalent load resistance value R/sub d/ are used to generate the sinusoidal current waveform. The DC voltage is directly controlled by the command input signal k/sub d/(=E/sub d//E/sub a/) for the boost chopper circuit. The DC voltage regulation is small because of the feed forward control for the AC line voltage E/sub a/ and no dependence of the circuit parameters. The sinusoidal current waveform in phase with the AC line voltage can be obtained. The feasibility of the proposed control system is verified by some simulation and experimental results.     

State-plane analysis of a constant-frequency clamped-modeparallel-resonant converter

A novel clamped-mode parallel-resonant converter which operates at a constant frequency and provides a wide output voltage regulation range is proposed and analyzed. Employing graphical state-plane techniques, five circuit operating modes are identified and their mode boundaries defined. Regions for natural and forced commutation of power devices are specified. The DC control-to-output characteristics are derived to facilitate converter design. The predicted operating modes are experimentally verified using a 105 kHz prototype circuit     

Dual sepic PWM switching-mode DC/DC power converter

A steady-state analysis and experimental results for a dual sepic pulse-width-modulated (PWM) DC/DC power converter for both continuous and discontinuous modes of operation are presented. The converter is dual to a sepic converter, but it can also be derived from a forward converter by replacing one of its rectifier diodes with a coupling capacitor. The circuit acts as a step-down or step-up converter, depending on the value of the ON switch duty cycle. The transformerless version of the converter has a positive DC/DC voltage transfer function. Therefore, the circuit is suitable for distributed power systems. Design equations for all circuit components are derived. Experimental results measured at 100 kHz were in good agreement with theoretical predictions     

无直流电压传感器的单相APFC变换器

文章对一种只检测交流输入电压而不需要检测输出直流电压的简化单相PFC变换器进行了理论分析和研究。在构建控制电路时,不需要常规PFC变换器中的输出电压传感器和输入电流传感器。PFC变换器的主电路为整流电路的直流侧接一级Boost电路。在控制电路中,使用电感L、等效负载电阻Rd等电路参数产生正弦电流波形基准,输出电压直接由控制量Kd(=Ed/Ea)来调节。通过控制,可以得到恒定的直流输出电压和与交流输入电压同相位的正弦电流波形。仿真结果证明了该变换器的可行性。     

一种DC/DC转换器的短路保护电路设计

针对负载短路会对DC/DC造成性能不稳定或损坏的情况,提出一种新型短路保护电路,有效地避免了传统电路在短路时大电流输出造成的能量浪费。该保护电路采用在负载短接时,通过改变电流限比较器输入端基准电压达到降低电路最大输出电流的措施。采用0.35 μm BCD工艺将该电路应用于一款高压同步BUCK型DC/DC转换器中,specter仿真结果表明,当负载短路时,该芯片的短路电流只有30 mA,与传统保护电路相比,降低了短路时的输出电流,达到节约能量的目的。     

数码相机电源DC/DC逆变电路研究

根据逆变系统的构成原理。设计出一种适合数码相机电源部分的DC／DC电路，并详细分析了所设计电路的工作原理和特性。     

Asymmetrical pulse-width-modulated resonant DC/DC convertertopologies

This paper presents asymmetrical pulse-width-modulated (APWM) DC/DC resonant converter topologies that exhibit near-zero switching losses while operating at constant and very high frequencies. The converters include a bridged chopper to convert the DC input voltage to a high-frequency unidirectional AC voltage, which in turn is fed to a high-frequency transformer through a resonant circuit. The bridged chopper has two switches that alternately conduct. The duty cycles of the conduction of the switches are complementary with one another and are varied to control the output voltage. Three resonant circuit configurations suitable for this type of control are presented. Frequency domain analysis of the converter is given, and performance characteristics are presented. Experimental results for a 48-5 V, 30 W converter show an efficiency of 88% at a constant operating frequency of 1 MHz     

基于MATLAB的Buck DC/DC变换器的仿真研究

阐述了直流降压变换器电路的工作原理,并且详细研究了在MATLAB/Simulink中的直流降压变换器的建模方法,此外文章还研究了带滤波器的Buck电路。最后给出了仿真结果并对其进行了分析,为直流降压变换器实际研究提供了方便。     

MLCC在DC/DC变换器中的应用和优化设计

通过分析电容器的寄生效应和频率特性,研究电容器等效串联电阻对DC/DC变换器电性能和稳定性的影响;明确了多层陶瓷电容器(MLCC)在DC/DC变换器应用中与其他种类电容器的不同之处;并对多层陶瓷电容器的优化设计方法进行探讨,用具体电路说明了优化设计过程。     

一种DC/DC斜坡补偿电路的设计

本文提出了一种峰值电流模式控制的DC/DC转换器中斜率补偿电路.电路采用上斜坡补偿（补偿信号与采样信号叠加）方式.电路由采样电路、斜坡信号产生电路、叠加电路共同组成.采样电路采样电感电流信号,并生成一个带有采样信号信息的电流信号,输入到叠加电路,与斜坡信号产生电路生成的一个斜坡电流信号进行叠加,然后共同作于一个电阻之上,输出一个带有采样信号信息与斜坡补偿信息的电压信号,实现斜坡补偿.该信号与误差放大器的输出信号共同输入到PWM（脉冲宽度调制）比较器,两信号经比较后输出驱动信号,控制功率管的关断.     

Dual-coupled inductor-fed DC/DC converter for battery drive applications

A new isolated boost DC/DC converter suitable for a low-input-voltage application is introduced. The proposed converter features low switch current stresses, wide range of input voltage, and inherent inrush current protection, essential for the design of a low-to-high-voltage conversion circuit. A comparative analysis and experimental results are presented to show the validity of the proposed converter.     

一种新型DC/DC变换器实验系统开发

为强化DC/DC变换技术的实践教学,基于多绕组变压器和反激电路原理,开发一套DC/DC变换器教学系统。设计变换器的拓扑结构,分析工作原理及控制策略,计算变换器系统参数,建立数字仿真模型,设计变换器主电路、输出电压采样电路、开关管驱动电路等来搭建变换器实验平台。实验教学应用表明,该变换器实现宽输入/输出电压范围功能的同时,能够提高学生的电力电子技术综合实践能力。     

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。     

丘克(Cuk)变换器的纹波电流及输出电压研究

建立了一种Cuk型DC／DC变换器的数学模型，并利用PSpiee软件对这种变换器进行仿真研究，分析其暂态和稳态的过程及纹波的形成机理。大量仿真研究表明，当电路元件取不同的参数时，输出电压就会按照一定的规律变化。仿真结果为实际电路的设计提供有益的参考。     

A high-frequency forward DC/DC converter topology with transformerflux balancing capability

The analysis and design of a high-frequency forward DC/DC power converter topology with transformer flux balancing capability is presented. The converter utilizes a main switch for load current commutation and an auxiliary switch for transformer flux balancing. Moreover, the converter topology provides the means to recover the energy associated with the parasitic inductances of the circuit components, thus yielding high efficiency and allowing for high operating frequencies. Experimental results for a 1 kW, 20 kHz prototype unit are presented     

基于单神经元PID控制的DC／DC变换器研究

DC／DC变换器是一种强非线性电路。电路的电气参数存在不确定性,负载性质也是多变的。主电路的性能必须满足负载大范围的变化,同时它还具有离散和变结构的特点,所有这些使DC／DC变换器控制器的设计较为复杂。由于传统的控制方法是基于线性系统理论,所以应用于DC／DC变换器中并不能获得理想的动态性能。文中针对DC／DC变换器的特点以及单神经元网络具有出色的知识抽取与学习能力及较强的控制鲁棒性。在现有的控制和建模方法的基础上,将神经网络控制策略引入DC／DC变换器,构造了一种基于单神经元的DC／DC变换器的新型控制方法。     

MC34063 DC/DC转换控制电路测试方法概述

目前,DC/DC转换器广泛应用于远程及数据通信、计算机、办公自动化设备、工业仪器仪表、军事、航天等领域,涉及到国民经济的各行各业。文章以其中有一定代表性的MC34063电路为例,扼要介绍其电特性和用其构成的升压电路的测试方法,并解析其测试原理和升压电路设计中的注意事项,对DC/DC转换器的分析测试和量产测试提供一些借鉴。     

基于MATLAB的单端反激式DC/DC变换器的仿真研究

阐述了单端反激式DC/DC变换器的工作原理,在此基础上研究了其在电流连续和断续工作情况下的电路运行模式,最后在MATLAB/Simulink中对理论分析进行了建模与仿真。仿真结果表明,电路在占空比和输出电阻发生改变时,单端反激式DC/DC变换器有可能从连续工作模式下变为断续工作模式。为实际电路的设计提供了方便。     

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.