双开关T型并联谐振逆变器拓扑结构研究

为实现感应加热电源高频化、高效率化及高功率输出能力,提出了以MOSFET作为开关的T型并联谐振逆变器电路拓扑结构。它能够输出理想的正弦电压波形,开关元件工作在零电压开关(ZVS)状态,降低了开关损耗,提高了工作频率和效率。逆变器的ZVS工作状态不受负载影响,且工作状态稳定,易控制。详述了电路构成及工作原理,研究并分析了电流、电压的关系,最后给出了实验结果。     

一种基于DSP新型三相逆变器谐振电路的控制方法

本文阐述了一种新型基于DSP三相DC-AC逆变器零电压开关(ZVS)拓扑电路的工作原理及其谐振控制方法，并就该控制方法中的问题及其对ZVS的影响作了详细分析，同时给出了相应的仿真波形与实验结果。     

三相四线制软开关SiC逆变器软开关工况分析

逆变电源的开关频率上限受到功率器件的动态损耗限制,导致较大的输出滤波元件的体积。零电压开关正弦脉宽调制(ZVS-SPWM)三相四线制逆变器电路只需引入1个辅助开关和2个较小的无源元件,就可以实现电路中所有开关器件的零电压开关。重点分析了SiC MOSFET寄生电容对零电压开关实现的影响,并在此基础上探讨了等效寄生电容值的提取方法,修正了零电压开关条件和功率器件电流、电压应力的计算值。最后在10 kW SiC MOSFET三相四线制零电压开关逆变器实验平台进行了验证。     

A one‐converter contactless charger for electric vehicles

A simple and reliable contactless battery charger for electric vehicles is proposed. Its feature is a unitized power factor correcting (PFC) converter and a high‐frequency inverter (HFI) where the low‐side switch of the HFI also works as the boost switch of the PFC in discontinuous conduction mode, which results in a high input power factor and low harmonic distortion without any feedforward control. The exiting current of the inductive connector, compliant with SAEJ1773, works effectively to make the converter operate in zero voltage switching (ZVS) condition. Another feature is that the charger is controlled by a single magnetically coupled variable frequency oscillator developed by the authors. This paper analyzes the circuits, gives a design example, describes the inductive connector and the oscillator, and presents experimental results. A 1.7‐kW output prototype charger achieved a charging efficiency of 87.4% for total one cycle charging, an overall efficiency of 90% at heavy load, and an input power factor of over 98%. © 2000 Scripta Technica, Electr Eng Jpn, 132(2): 73–81, 2000     

软开关交错反激光伏并网逆变器

提出一种应用于单个光伏组件的软开关交错反激并网逆变器拓扑及其软开关控制策略。针对反激变压器漏感问题,提出漏感能量吸收回馈电路,实现了漏感能量吸收再利用,并实现了开关管漏源电压的钳位,提高了变换效率同时降低了开关管关断电压尖峰;提出基于数字处理器的反激变换器变开关频率谐振软开关控制策略,实现了开关管的零电压开通,同时改善了逆变器的电磁兼容特性;提出的交错并联反激逆变器有助于减小变压器和滤波器的体积,提高功率密度。详细分析变换器的工作原理,分析变开关频率谐振软开关控制方式的原理和实现条件,最后进行实验验证。     

新型软开关三相并网逆变器

提出了一种新型软开关三相逆变器,可以只采用一个辅助开关实现所有开关的零电压开通(ZVS),并抑制二极管反向恢复。逆变器的主开关和辅助开关具有相同且固定的开关频率,主开关和辅助开关电压应力均等于直流母线电压。分析了软开关三相桥式并网逆变器的软开关过程,研制了20 kW试验样机并完成了试验验证。     

一种高效率软开关三相并网逆变器

提出一种只采用一个辅助开关,即能实现所有开关的零电压开通,并能抑制二极管反向恢复的高效率软开关三相并网逆变器.逆变器可以采用空间矢量调制(SVM)策略,主开关和辅助开关具有相同且固定的开关频率.分析了软开关三相并网逆变器的开关过程,给出了谐振参数设计步骤.研制了20 kW实验样机并完成了实验验证,实验结果表明,并网逆变...     

An integrated controller for high‐frequency LCLC resonant inverter with phase‐shifted control and frequency regulation

High‐frequency alternating current has an extensive application as a result of outstanding advantages. The aim of the study is to develop a high‐frequency power source to feed the auxiliary loads of vehicle application such as electric fans, blower motors, and lighting. A feasible implementation of high‐frequency power source is examined by a full‐bridge LCLC resonant inverter. The corresponding control scheme is proposed for the fourth‐order resonant inverter to confront the control challenges of low output harmonics and dynamic nonlinear load. Firstly, an analysis parameter S _r is defined to address the possible impacts of the varying operational frequency to output THD and ZVS features. Secondly, an integrated control scheme is presented to implement pulse‐width control at heavy load and frequency regulation at light load. Lastly, an experimental prototype is accomplished with the peak voltage of 35 V and the output power of 120 W. The accordance of experimental results and theoretical analysis testifies that the proposed control scheme can achieve the low harmonics and high conversion efficiency over a wide scope of operational conditions. Copyright © 2016 John Wiley & Sons, Ltd.     

对称控制全桥谐振PWM软开关变换器

针对传统对称控制全桥变换器不能实现软开关而导致变换器效率较低的现状,提出了对称控制全桥谐振PWM(FB-RPWM)变换器,详细分析了FB-RPWM变换器的工作模式及其稳态特性。分析结果表明:FB-RPWM变换器虽然采用对称控制,却仍在全负载范围内实现了所有桥臂开关管的零电压开通(ZVS)和输出二极管的零电流关断(ZCS),且其输入输出电压传输比与负载、开关频率和占空比无关,呈现出直-直变压器(DCX)的工作特性。与移相全桥(PSFB)变换器相比,FB-RPWM变换器减小了两个开关管的关断电流,且变压器一次侧采用隔直电容,实现了励磁电感电流的零直流偏量,降低了变压器损耗,进一步提高了变换器的效率。最后,搭建了一台400V输入、50V/10A输出的实验装置,验证了理论分析的正确性。     

ZVS-PWM电路中无损吸收回路分析

详细研究了移相控制全桥零电压开关脉宽调制变换器(FB-ZVS-PW M )的换流过程。分析得出,若考虑开关管关断过程中的电流下降特性,则当开关管关断时,在无损吸收回路的作用下,电路关断换流过程会出现两个不同的换流阶段,并在此基础上推导出这两个不同阶段的换流方程。针对其滞后桥臂负载电感偏小给零电压导通造成的困难,文中放弃了负载电流为恒流源的假设,推导出描述其换流过程的方程。基于这些方程,研究了实现软开关的条件,并从关断损耗和占空比丢失的角度探讨了吸收电容与电路最高工作频率的关系,给出了工程设计公式。仿真和实验结果验证了该方程的正确性。     

新型谐振直流环节软开关逆变器

为了提高开关变换器的效率和增强性能,提出了一种新的谐振直流环节软开关电压源逆变器,通过在传统硬开关逆变器的直流环节添加辅助谐振单元,使直流环节电压周期性出现零电压凹槽,实现逆变桥开关器件在零电压条件下的切换,减小了开关损耗和二极管的反向恢复损耗。同时,辅助谐振单元的开关也为零电流或零电压条件下的软开关操作。详细阐述了该软开关逆变器拓扑的工作原理和动作模式,并对软开关动作时序的瞬态过渡过程进行了数学分析。最后,对提出的新型软开关逆变器驱动三相R-L负载进行了仿真研究,仿真结果验证了电路结构和理论分析的正确性与可行性。     

多包络线谐振软开关逆变器控制策略

为了满足光伏微型逆变器高功率密度、高性能、低总谐波畸变率(total harmonic distortion,THD)的要求,文中基于临界电流模式提出一种多包络线谐振软开关逆变器控制策略,通过进行开关管的分时控制达到平衡电感电流上升下降时间的目的,从而缓解过零点畸变。随后,详细介绍多包络线谐振软开关逆变器控制策略的工作模态,并从软开关、开关频率、开关管损耗与逆变效率、过零点畸变程度等方面与传统临界电流模式进行对比分析。为验证控制策略的有效性,文中基于PSIM搭建了500 W谐振软开关单相全桥逆变器进行开环仿真验证。仿真结果表明,与传统的单极性临界电流模式相比,多包络线临界电流模式可以有效优化过零点问题,能够滤除谐波、降低THD,并且实现零电流开关(zero current switch,ZCS)和全部开关管的零电压开关(zero voltage switch,ZVS)。     

A highly efficient single‐phase sine‐wave inverter with single‐switch high‐frequency modulation

This paper presents a highly efficient single‐phase sine‐wave inverter with single‐switch high‐frequency modulation. In this topology, a control circuit is connected at the lower arm of a full‐bridge inverter to control the output voltage across the full‐bridge inverter. The switch at the lower arm of the full‐bridge inverter controls the output voltage of the full‐bridge inverter by increasing or reducing the voltage level at the lower arm of the inverter. This switch of lower arm is controlled by a high‐frequency sinusoidal pulse width modulation (SPWM) switching signal, while the power switches of the full‐bridge inverter operate with a square‐wave switching signal at the line frequency to unfold DC–AC inversion, thus producing a sinusoidal voltage at the load. Both computer simulation and experiment are carried out to verify the performance of the proposed topology. Experimental results from a 1000‐W laboratory prototype are presented to testify and validate the analysis, design, and performance of the proposed topology. The results show that the proposed topology has nearly sinusoidal output voltage and current waveforms with a total harmonics distortion of less than 5%. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

2种ZVS方式AHB直流变换器比较

不对称半桥(AHB)直流变换器原边开关管实现零电压开关(ZVS)的方式有2种:负载电流ZVS方式和激磁电流ZVS方式.对2种不同ZVS方式AHB变换器的电路工作原理、控制策略、关键参数设计依据进行了深入的比较研究,并研制了2台原理样机,给出了实验波形及测试结果.研究及实验结果表明:负载电流ZVS方式AHB变换器利用负载折射电流实现开关管的ZVS,负载较小时.开关管ZVS难以实现,其采用增大变压器漏感或外串电感的方法来扩大ZVS负载范围,适用于较大功率应用场合:而激磁电流ZVS方式AHB变换器利用变压器激磁电流,可在空载至满载范围内实现开关管ZVS.相对于负载电流ZVS方式,其效率略低,适用于小功率应用场合.     

性能优良的高频软开关三相逆变电源

对基于占空比扩展有源箝位正激式高频脉冲直流环节逆变器的组合式三相逆变电源的电路拓扑、稳态原理、三态DPM电流滞环控制技术、负载特性、关键电路参数设计进行了深入的分析研究。设计并研制成功了3kVA27VDC/200V400HzAC高频软开关三相逆变电源,它具有体积重量小、变换效率高、静态精度高、动态响应快、输入电压变化范围宽、输出波形质量高、过载与短路能力强、带三相不平衡负载的能力强、逆变桥功率开关实现ZVS等优良的综合性能。     

Analysis,simulation and verification of a bipolar current source power resonant inverter

A high‐frequency bipolar current source resonant inverter introduced in this paper has dramatic zero‐voltage‐switching (ZVS) characteristic. The analytic expressions of the resonant voltage and current are given. It indicates that the resonant waveform is composed of two parts, i.e. the oscillatory component and the stationary component. In special cases, the resonant waveform degenerates into the mono‐frequency component, as presents the graceful sinusoidal wave with very low total harmonic distortion (THD) value. Based on the closed‐form voltage and current, the component stresses on reactive elements are obtained. The impact of different component values and operating frequencies on ZVS feature is also discussed. It should be noted that the ZVS merit may be lost if the components are carelessly selected. The validity of the theoretical analysis has been proven with Pspice simulations and experimental results. Copyright © 2004 John Wiley Sons, Ltd.     

无扰切换技术在电厂引风机高压变频器中的应用

高压变频器在发电厂引风机使用中,常因变频器故障需单侧停机,目前常用措施是降低机组负荷单侧停机检修,严重影响机组负荷,经济损失大,提出一种通过为变频器增加无扰切换柜,实现引风机变频方式与工频方式的双向切换,且切换电流小,对母管风压无影响,机组负荷稳定。通过实验验证该方法的可行性。     

三电平LLC谐振型DC/DC变换器的分析和设计

将三电平技术和LLC谐振变换器结合起来，提出三电平LLC谐振变换器。根据等效电路模型推导出该变换器输入输出电压的增益与开关频率、负载之间的关系，揭示其开路和短路特性，为该变换器的空载工作和短路保护的设计提供了理论基础。提供了该变换器两个死区时间的设计方法，从而保证了开关电压应力限制在输入电压的一半，同时满足每个开关零电压关断的实现条件。谐振参数可用推荐的方法依照变比n谐振电容Cs、谐振电感Ls、谐振电感Lm、的次序来设计。最后根据所提供的设计方法设计了一个540W样机，性能和结果满足要求，效率达94．7％。     

新型无刷直流电动机专用谐振极逆变器研究

无刷直流电动机通常采用硬开关逆变器驱动.硬开关逆变器的系统效率较低,散热器的体积和重量较大,限制了无刷直流电动机驱动系统功率密度和性能的进一步提升.针对硬开关逆变器问题,提出了一种无刷直流电动机驱动系统专用的谐振极软开关电压源逆变器.通过在传统硬开关逆变器三个输出端和直流母线之间添加辅助谐振单元,实现了逆变桥主开关器件的PWM软开关动作.谐振控制开关零电流开关条件开通,零电压开关条件关断.对提出的新型谐振极逆变器进行了数学分析和仿真研究;仿真结果验证了电路结构和理论分析的正确性与可行性.     

Fifth‐order Π‐type load resonant converters analysis based‐on immittance property for constant output current applications

Passive resonant tanks (PRTs) with immittance property are suitable candidates to achieve constant output current in load resonant converters (LRCs). In this paper, fifth‐order Π‐type LC networks are investigated to accede this target. At the first step, fifth‐order Π‐type passive LC networks that can be applied as a PRT are specified based on source and sink natures. Also, their structural advantages are described in detail to give a suitable perspective for the topology selection. At the second step, immittance property is verified for the proposed topologies and immittance PRTs (IPRTs), with their immittance operation conditions, are derived. To confirm the effectiveness, a 150‐W LRC is implemented leveraging new Π‐type IPRTs. A deep investigation is devoted to analyze the current/voltage stress in the components of the designed LRC. Moreover, kVA/kW ratio is considered as a key parameter for the reactive component size minimization. The proposed constant current LRC presents high load regulation capability in addition to the minimum reactive power and zero‐voltage switching (ZVS) on the inverter MOSFETs under the various loads. A significant robustness against load variations, less sensitivity versus parameters variation, and relatively higher efficiency are the main superiorities of the fifth‐order IPRTs to the lower order counterparts.