一类零电流谐振开关电容变换器的特性分析

具有零电流开关特性的谐振开关电容变换器是开关电容变换器的一种新拓扑形式.本文着重分析电路寄生参数和变换器运行条件对该类谐振开关电容变换器稳态特性的影响,推出变换器输出电压和效率的数学表达式,为研究负载或输入电压变化时变换器的输出性能提供了分析和设计依据.基于输出电压表达式,还提出谐振开关电容变换器的频率控制方案.全文以一个降压式谐振开关电容变换器为例详细说明公式的推导过程,并将此稳态特性分析推广到其它类型的谐振开关电容变换器.最后,文中设计了一台12V/5V/2.5A降压式谐振开关电容变换器样机,实验结果验证了本文的理论分析结果.     

基于图论的n阶升压式谐振开关电容变换器潜电路分析技术

高阶升压式谐振开关电容变换器的升压阶数增加,拓扑变得更加复杂,其潜在路径隐蔽性更强,因而需要研究一种系统的分析方法.为此本文基于图论提出一种n阶升压式谐振开关电容变换器潜电路分析方法,文中给出了该图论分析法的原理和步骤,并以3阶升压式谐振开关电容变换器为例进行了仿真和实验证明.研究结果表明,该方法简单易行,是一种可供推广的电力电子变换器的潜电路分析方法,为预先发现和消除高阶升压式谐振开关电容变换器中的安全隐患提供了理论依据.     

基于电力电子变换器广义连接矩阵的潜电路分析方法

本文通过建立非线性电力电子变换器拓扑有向图,提出了能够识别给定电力电子拓扑所有开关回路的广义连接矩阵分析方法,在此基础上,根据路径判据剔除虚假回路,可辨别正常工作回路和潜电路路径。同时,基于所提出的广义连接矩阵分析方法,对存在潜电路的DC／DC升压式谐振开关电容变换器进行了详细的应用研究分析,验证实例证明了所提出方法是正确和有效的。     

谐振开关电容变换器的潜电路特性

潜电路是一种潜伏在系统中的路径或状态,仅在特定的条件下产生,使系统出现非期望的功能.本文以一个降压式谐振开关电容变换器为例,详细分析了潜电路出现时变换器的工作过程,利用电路能量守恒定理推导出变换器的潜电路特性以及潜电路发生条件.得到潜电路出现后,变换器的输出电压不再保持恒定,而是与电路参数、运行条件等密切相关,呈现出非预期特性的结论,并用实验结果加以证实.     

多输出谐振型开关电容变换器的设计与仿真

开关电容变换器是一种典型的无感变换器,电路中主要由开关管和电容器来实现电压变换和能量转换。由于电路中不含电感和变压器,可以大大缩小电源体积、减轻重量,并且易于在芯片上集成。随着电子设备的小型化,开关电容DC-DC变换器将具有广阔的应用前景。基于开关电容DC-DC变换器的研究现状,文中系统地阐述了多输出开关电容DC-DC变换器的工作原理和设计方法,并通过系统仿真和实验验证了该类谐振型变换器的高效性。     

采用有源电容倍增器改善开关电容DC-DC变换器的性能

研究了开关电容DC-DC变换器输出电压与电容的关系,分析了变换器输出电压波纹产生的原因.针对变换器中大电容难集成的问题,提出了一种基于跨导放大器和第二代电流传输器的有源电容倍增器的新型拓扑结构.该电路只用较少的元件就可以实现开关电容变换器中的浮地和接地电容.以二阶开关电容DC-DC变换器为例,用PSPICE软件分别对采用了有源电容倍增器的新型结构和传统结构进行了仿真.结果显示,基于有源电容倍增器的开关电容变换器仅用100pF电容就等效了200nF电容的输出性能,而且具有更低的输出电压波纹.     

电流准谐振变换器的性能分析

本文对电流准谐振变换器电路的工作原理进行了分析,给出了准谐振电路在电网、负载变化时变换频率和功率开关导通时间变化的规律,分析了这种变换器的功率输出与变换频率、闭环方式的关系。     

电流准谐振变换器的性能分析

本文对电流准谐振变换器电路的工作原理进行了分析，给出了准谐振电路在电网、负载变化时变换频率和功率开关导通时间变化的规律，分析了这种变换器的功率输出与变换频率，闭环方式的关系。     

一种高功率密度高效率DC-DC变换器的研究

直流低电压输入、大功率输出、小型化电源在面阵、固态功放等场合有广泛应用。针对这一需求,对一个基于LLC谐振的1MHz、600W直流变换器电路进行设计分析,并利用Saber对理论设计进行了仿真验证,谐振电容为0.33μF,谐振电感为77nH,有效减小了谐振元件尺寸。仿真结果表明该结构可以有效实现软开关效果,转换效率高达97%。     

一种零电压开关Zeta变换器的设计

给出了一种零电压开关Zeta变换器,这种变换器可以提高效率和减小功率开关管的电压应力.当变换器工作在连续模式时,应用谐振电容和变压器的漏感实现功率开关管的零电压导通.详细分析了变换器的工作原理,并设计了相应的电路进行验证.仿真结果表明所设计的Zeta变换器效率达92.21%,输出电压纹波为125 mV.它可被用于等离子显示屏(PDP)电源系统.     

AC-DC converter with parametric reactive power compensation

Resonant converters of 50 (60) Hz AC-DC are described, where each half cycle of network voltage the capacitor and inductor of an oscillatory circuit are switched from series into parallel and vice versa. The duration of series and parallel connection and also the transformer ratio are parametrically dependent on load. In the case of short circuit, only the parallel oscillating circuit operates. This restricts sharply the output current. The reactive power of the capacitor and the inductor compensate each other, both in the cases of series and parallel connection. Therefore, the power factor is very high from no load to short circuit. This converter fits very well for supplying arc furnaces, and there is no need for the costly and fast reactive power compensator and filter circuits. The operating principle of the converter, design principles, and a real operating converter rated 5.4 MW supplying a steel-melting arc furnace are described     

串联谐振电容器充电电源特性研究

负载与谐振回路L-C以串联形式输出称为串联谐振变换器,将串联谐振变换器应用到电容器充电技术中,产生了串联谐振电容器充电电源（CCPS）。和普通电容器充电电源相比,串联谐振电容器充电电源具有抗负载短路能力强、体积小、控制简单、可开环控制等优点,在国防科研中得到广泛应用。为了研究串联谐振CCPS电路的工作特性,文章给出了其电路原理图及等效电路,建立了该电路的数学模型。通过数学仿真的方法,给出了谐振电路的特性。实验结果验证了所采用控制方案的正确性和充电系统的有效性。     

A variable step-down conversion ratio switched capacitor DC-DC converter for energy harvesting systems working in intermittent mode

Energy harvesting systems stimulate the development of power management for low power consumption applications. Improving the converter efficiency of power management circuits has become a significant issue in energy harvesting system design. This paper presents a variable step-down conversion ratio switched capacitor (SC)DC-DC converter to advance the converter efficiency of charge on the stored capacitor in a wireless monitoring system of orthopedic implants. The converter is designed to work at 1 MHz switching frequency and achieves 15 to 2 V conversion. Measurement results show that the converter efficiency can reach 4:2% including all circuit power consumption, which is much higher than previous work.     

A New PWM-Controlled Quasi-Resonant Converter for a High Efficiency PDP Sustaining Power Module

A new pulsewidth modulation (PWM)-controlled quasi-resonant converter for a high-efficiency plasma display panel (PDP) sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the primary resonant capacitor with a bidirectional auxiliary circuit, while the main switches are operating at a fixed duty ratio and fixed switching frequency. Hence, the waveforms of the currents can be expected to be optimized from the view-point of conduction loss. Furthermore, the proposed converter has good zero-voltage switching (ZVS) capability, simple control circuits, no hign-voltage ringing problem of rectifier diodes, no dc offset of the magnetizing current and low-voltage stresses of power switches. Thus, the proposed converter shows higher efficiency than that of a half-bridge LLC resonant converter under light load condition. Although it shows the lower efficiency at heavy load, because of the increased power loss in auxiliary circuit, it still shows the high efficiency around 94%. In this paper, operational principles, features of the proposed converter, and analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit using the PWM method.      

多体电源并联电路的潜通路分析

潜通路问题在航天装备型号研制试验中经常遇到,有些造成航天装备型号不能正常发射,甚至影响发射成败。潜通路分析及排除比较困难。本文介绍了一种由于多体电源关联,启动不同步形成潜通路,造成计算机上电复位不稳定,从而导致控制电路误动作,影响发射的故障及其分析方法。首先要找出可能造成故障的模式,然后对电路图进行认真分析,查找出设计...     

GaAs switched capacitor DC-to-DC converter

A switched capacitor DC-to-DC negative converter fabricated in GaAs MESFET technology is introduced in this paper. The converter has an oscillator that runs at 250 kHz, and requires two external capacitors, 0.1 and 1 μF. The converter runs off a wide range of supply voltage, 2 to 10 V, and has a typical output impedance of 75 Ω. A typical open circuit voltage conversion efficiency of 99.6% is achieved. The circuit can be integrated with other GaAs circuits to provide an on-chip negative supply. Measured, simulated and analytical results are introduced in this paper