基于移相控制的串联谐振变换器稳态分析

将基波分析法应用到基于移相控制的串联谐振变换器,以电路稳态模型为基础计算出变换器的电压增益、电路阻抗、谐振电容电压和谐振电感电流、电压电流应力及功率,得到这些量与工作频率、占空比及等效负载品质因数之间的数学表达式,并通过仿真图形进行直观显示。最后通过搭建的电路进行了实验验证。     

LC串联谐振和LCC串并联谐振在高压脉冲电容充电电源中的应用比较

为得到更适合高压脉冲电容充电电源的电路拓扑,对LC串联谐振和LCC串并联谐振充电电源的应用电路特性进行了比较。利用Matlab分别对LC串联谐振和LCC串并联谐振脉冲电容充电电路进行了仿真分析,通过3kW电源样机对600μF/15kV负载电容进行了充电实验,给出了LCC串并联谐振实验波形,与仿真结果一致。实验结果说明实际LC串联谐振电路由于分布电容的影响变为LCC串并联谐振,并根据附加并联电容对电路分布电容的大小进行了间接测量,LCC串并联谐振所需供电电源功率较小、电流峰值较低、充电精度较高,因而更具优越性。     

20kJ/s电容充电电源的分析与设计

采用开关变换技术的串联谐振电容充电电源是较为理想的电容充电方式。为此,先后对串联谐振电容充电电源进行了最小应力设计,对后级共振充电电源进行了分析与设计。前者主要根据谐振电感和电容峰值能量以及开关器件的最大功率建立了应力函数,通过求解应力函数的最小值确定了电路的工作点和器件参数。实验结果与理论计算结果相一致,电源在最小应力点工作时器件的综合应力最小,并且开关频率高于谐振频率工作时比低于谐振频率工作时应力更小。最后给出了一台应用于磁脉冲压缩系统的初级储能电容充电电源的设计实例,其电源的实验结果与理论计算结果相一致,负载电容在5~40μF之间变化时,系统可在100 Hz重复频率下稳定、可靠地长时间运行。根据最小应力公式进行谐振变换器和电容器充电电源的分析与设计可为设计者提供参考。     

变频微波炉电源用LLC谐振变换器

研制了一款专为变频微波炉中磁控管供电的高频软开关电源。采用倍压输出式LLC谐振变换器作为该电源的主电路,并用基波分析法建立了其稳态基波等效电路模型;对其直流增益、谐振电流及零电压导通条件等进行了分析,并对高频变压器的电压比、品质因数、励磁电感、谐振电感及谐振电容等核心参数进行了优化设计。仿真和实验表明所建立的稳态电路模型及其理论分析是正确的,给出的谐振网络参数及其优化设计是正确的,这对于分析、研究和改进变频微波炉电源的设计及指导生产具有现实意义。     

基于恒流源充电软开关型高压直流电源的研究

在开关频率小于1/2谐振频率的情况下,串联谐振变换器具有对小电容负载进行"等台阶"恒流线性充电和软开关特性。推导并分析了串联谐振变换器在一个工作周期内的6种工作模式及每种模式下的谐振电感电流和谐振电容电压公式。利用全桥串联谐振变换器对倍压整流器进行类似"均充"恒流充电,结合脉幅调制(Pulse Amplitude Modulation,简称PAM)和脉频调制(Pulse Frequence Modulation,简称PFM)控制方式,研制了一台软开关型高压直流电源。电源的设计过程和测试结果分析表明,该电源满足了软开关和恒流源充电的要求。最后提出一种采用多模块串联叠加技术来提高功率的改进方案。     

SLR式软开关充电电源的设计

设计了一种以串联负载谐振变换器为主电路拓扑的充电电源,介绍了串联负载谐振变换器的工作原理和软开关特性。分析了在电池负载条件下电路的电流特性,设计了控制电路,通过定脉宽调频控制实现对负载的恒流充电。针对输出电流纹波较大的问题,设计了电源模块交错并联的解决方法,仿真验证了该方法的可行性。研制了一台电源模块样机,实验结果表明...     

串联谐振变换器的稳态模型

谐振变换器是依靠改变开关网络的工作频率实现对输出量的控制的,因此它是一种变频控制的开关调节系统。像PWM型开关调节系统一样,这种开关调节系统也是一种强非线性、离散的病态系统,要精确的建立其数学模型并从理论上得到系统的瞬态解和稳态解是较为困难的,更不能用经典控制理论设计控制器并研究其稳定性。因为在传输能量方面,PWM型变换器是靠平均值传输能量的,而谐振型变换器是靠"基波"传输能量。所以在稳态分析时,PWM型变换器采用平均值分析法,而谐振变换器采用了基波分析法。本文详细介绍了串联谐振变换器稳态模型的建立方法。     

一种高压脉冲电源充电技术的研究

介绍一种以串联谐振变换器为充电电路的高压脉冲电源充电技术，分析了电路的工作原理，给出了电路设计时各主要参数的选择方法以及几个关键点的仿真波形。实验结果表明该电源具有体积小、精度高等特点。     

基于LLC谐振变换器的微波炉用高压变频电源

传统的微波炉电源多采用工频变压器升压的供电方式,此类电源功率密度小、效率低、开关噪声大,对电网污染较大.针对这些问题,设计了一个输出端采用倍压整流方式的LLC谐振软开关变换器作为主电路,L6599芯片为控制核心的高压变频电源.应用基波分析法推导出变换器的直流增益,分析谐振网络的谐振电感系数和品质因数的曲线变化,优化变换器的谐振参数.利用MATLAB、SABER仿真软件分析主电路的工作特性.最后通过实验验证了该设计方案的合理性与正确性.     

串联负载谐振式DBD型臭氧发生器电源的基波分析法研究

由于介质阻挡放电电路(dielectric-barrier discharge, DBD)存在放电和未放电两个模态，电路的模态和电源的模态相互组合使电路工作的模态很复杂。为了能在工程中便利地为DBD电路设计供电电源，在分析一种移相全桥脉宽控制下的串联负载谐振式DBD电路电流的基础上，利用串联逆变器供电的DBD电路电流接近正弦波这一特性，提出了DBD电路的基波分析方法，推导了DBD电路的基波等效电路，并采用实验和仿真的方法对基波分析方法进行了验证。分析表明采用基波分析法得到的计算值与仿真和实验结果之间的相互误差均小于8%，这就验证了该文分析方法的正确性。与一般的分析方法相比，提出的设计和分析方法具有简单和方便的特点，具有现实的工程意义。     

Analysis and design of a half‐bridge LLC series resonant converter employing two transformers

This paper presents a two‐transformer LLC series resonant converter (SRC), which is derived from incorporating two identical converters. The proposed converter allows a low‐profile power supply design for liquid crystal display (LCD) TVs and servers. The presented converter can equally share the total load current between two transformers and the output rectifier modules. Therefore, the heat problem can be effectively relieved. The steady‐state analysis and design of this new two‐transformer LLC SRC are described. The experimental results are recorded for a prototype converter with an output voltage of 12thinspaceV, an output power of 300 W, and a resonant frequency of 74 kHz. Copyright © 2011 John Wiley & Sons, Ltd.     

脉冲高压电源的控制与分析

为解决环流器二号(HL-2A)装置的脉冲高压电源输出在投入负载速调管时存在的电压跌落和前级电源在其它负荷发生变化时其输出电压也会变化的问题,利用MATLAB数字仿真试验后对该电源系统采用了PID反馈控制与前馈补偿策略。仿真与实际应用结果均表明,该控制策略能很好地满足该电源电压稳定性的要求。     

零电流准谐振Buck变换器的磁集成研究

以零电流准谐振Buck变换器为例,引入谐振电感和谐振电容与变换器中的功率开关管组成谐振开关.通过谐振,使流过功率开关管的电流呈正弦波形,为功率开关管创造了零电流开关条件.对分立的谐振电感和滤波电感进行磁集成,阐述集成后Buck变换器工作原理.用Saber软件对集成后的电路进行仿真.分析谐振电感和滤波电感的耦合系数对谐振...     

串并联谐振倍压变换器高压电源的设计与研究

为了满足高电压小电流特别是小体积的要求,设计了一种软开关变换器(串并联谐振倍压变换器)的技术方案。该变换器的优点在于利用谐振元件吸收了电路寄生参数,消除了电路寄生振荡。并实现开关管的零压开通。同时利用倍压整流技术,解决了传统高压电源方案中升压变压器升压倍数大、体积笨重、制作难度大的问题。与传统的串并联谐振变换器相比,该变换器采用容性滤波模式,使串并联谐振变换器在高压小电流的应用中得以实现。简要分析了该变换器在工作负载时的工作原理,并利用正弦交流法建立了系统数学模型,绘出了变换器的输出特性曲线图。提出了一种适用于LCC谐振倍压电路的参数设计方法。实验结果证明了该新型变换器原理和理论分析的正确性。     

Analysis and implementation of a soft switching DC/DC converter with three asymmetric PWM circuits

This paper presents a soft switching converter with three buck‐type active clamp circuits (or asymmetric half‐bridge circuits) to achieve the functions of the low power rating on the transformers and power semiconductors and low current rating on the rectifier diodes and output inductors. Three half‐bridge circuits are stacked at the high voltage side to reduce the voltage stress of each power switch at one‐half of input voltage and connected in parallel at the low voltage side to share load current and reduce the current rating on each magnetic component and the rectifier diode. Thus, the size of the output chokes is reduced. In each half‐bridge converter, the asymmetric pulse‐width modulation is adopted to control power switches. Power MOSFETs can be turned on with zero voltage during the transition interval due to the resonant behavior by the output capacitance of MOSFETs and the leakage inductance (or external inductance) of transformers. Experiments based on a laboratory prototype with 1 kW rated power are provided to demonstrate the performance of proposed converter. Copyright © 2012 John Wiley & Sons, Ltd.     

Modeling and simulation of ac–dc buck-boost converter fed dc motor with uniform PWM technique

PWM controlled rectifiers can efficiently and economically be employed in low and medium power applications of dc drives and in front-end converters of rectifier–inverter systems while maintaining the advantages of design simplicity and operation reliability of naturally commutated schemes. Due to the high dc voltage that is produced which is greater than the peak voltage of the utility supply, the ac–dc buck-boost converter is especially suited as a front-end power source in variable-speed drive systems to convert the utility supply voltage into a variable dc link voltage where a single-phase or a three-phase utilities power supply is available. In this paper, the dynamic model and steady state equivalent circuit of a single-phase ac–dc buck-boost converter fed dc motor with uniform PWM control is presented. The waveforms of voltage and current, the input and output characteristics of the converter are discussed and verified. Measured, computed and simulated results are shown to be very close and the model is proved to be efficient and accurate.     

一种新颖的三电平软开关谐振型DC/DC变换器

该文提出一种新颖的三电平LLC串联电流谐振型DC/DC变换器。每个主开关电压应力是输入电压的一半，并且全范围实现ZVS而不用附加任何电路。整流二极管工作在ZCS状态。该变换器通过二次谐振的手段使得以较小的频率变化范围就可以实现较大的输入输出调节范围。整个变换器只需一颗磁元件。该变换器在高压端输入时效率较高，应用在要求有保持时间的电源产品上特别有利。文中通过一个500V～700V输入，54V／10A输出的样机验证了它的工作原理和特点。该样机在额定条件下效率达到94．7％。     

Analysis and Implementation of an Interleaved ZVS Converter with High Input Voltage

An interleaved half‐bridge converter is presented for high input voltage application. The features of the proposed converter are zero voltage switching (ZVS) turn‐on for all active switches, ripple current reduction at output side, load current sharing and load voltage regulation. Two half‐bridge converters connected in series and two split capacitors are used to limit the voltage stress of each power switch at one‐half of input DC bus voltage. Thus, active switches with low voltage stress can be used at high input voltage application. On the other hand, the output sides of two half‐bridge converters are connected in parallel to share the load current and reduce the current stresses of the secondary windings and the rectifier diodes. Since two half‐bridge converters are operated with interleaved pulse‐width modulation (PWM), the output ripple current can partially cancel each other such that the resultant ripple current at output side is reduced and the size of output inductors can be reduced. In each half‐bridge converter, asymmetrical PWM scheme is used to regulate the output voltage. Based on the resonant behavior by the output capacitance of MOSFETs and the leakage inductance (or external inductance) of transformers, active switches can be turned on at ZVS during the transition interval. Thus, the switching losses of power MOSFETs are reduced. The proposed converter can be applied for high input voltage applications such as three‐phase 380‐V utility system. Finally, experiments based on a laboratory prototype with 960‐W rated power are provided to demonstrate the performance of proposed converter. Copyright © 2012 John Wiley & Sons, Ltd.     

ZVS DC/DC converter with series half‐bridge legs for high voltage application

This paper presents a new DC/DC converter with series half‐bridge legs for high voltage application. Two half‐bridge legs connected in series and two split capacitors are used in the proposed circuit to limit the voltage stress of each active switch at one‐half of input voltage. Thus, active switches with low voltage stress can be used at high DC bus application. In the proposed converter, two circuit modules are operated with an interleaved pulse‐width modulation scheme to reduce the input and output ripple currents and to achieve load current sharing. In each circuit module, two resonant tanks are operated with phase‐shift one‐half of switching cycle such that the frequency of the input current is twice the frequency of the resonant inductor current. Based on the resonant behavior, all MOSFETs are turned on at zero voltage switching with the wide ranges of input voltage and load conditions. The rectifier diodes can be turned off at zero current switching if the switching frequency is less than the series resonant frequency. Thus, the switching losses on power semiconductors are reduced. The proposed converter can be applied for high input voltage applications such as three‐phase 380‐V utility system. Finally, experiments based on a laboratory prototype with 960‐W rated power are provided to demonstrate the performance of proposed converter. Copyright © 2011 John Wiley & Sons, Ltd.     

复合式全桥三电平LLC谐振变换器

该文提出了一种适合于燃料电池供电系统新颖的复合式全桥三电平LLC谐振变换器。它是在复合式全桥三电平变换器的基础上加入了LLC谐振网路以实现开关管ZVS和整流二极管ZCS。该变换器集合了复合式全桥三电平变换器和LLC谐振变换器的优点：适合于在宽输入电压范围的应用场合；三点平桥臂的开关管电压应力只有输入电压的一半；整流二极管实现ZCS，其电压应力仅为输出电压；可以在全负载范围内实现ZVS。该文通过一个200－400V输入，360V/4A输出的原理样机验证了它的工作原理，并给出实验结果。