Boost ZCT-PWM变换器的改进及仿真分析

针对传统的Boost ZCT-PWM变换器中存在的主开关管硬开通和辅助开关管硬关断的问题,提出一种改进型的Boost ZCT-PWM变换器,使主开关管零电流开通,辅助开关管零电流通断,并且特别适用于IGBT作为开关器件的高电压、大功率应用场合。分析电路的工作原理并用PSpice仿真软件进行仿真研究。仿真结果表明所有开关器件实现了软开关,变换器的效率得到提高。     

一种新型无源软开关变换器

 为实现一种结构简单、高效、高频、低的电压应力、易于控制的软开关变换器.提出了一种新型无源软开关变换器.它通过采用简单的无源辅助谐振网络实现了开关管的软开关,开关管电压电流应力小,解决了输出二极管反向恢复问题.特别适用于以IGBT(Insulated Gate Bipolar Transistor)作为开关器件的高电压大功率场合.该文以其在Boost变换器的应用为例分析了它的工作原理,软开关实现条件,给出了谐振参数的设计方法,该软开关设计思想可以推广到其他基本的DC-DC变换器中.制作了一个使用IGBT的5kW~20kHz的实验样机,通过实验验证了该变换器的有效性.     

新型三相谐振极软开关逆变器

为提高三相逆变器的转换效率,提出了一种新型三相谐振极软开关逆变器拓扑结构,通过在每相桥臂上增加结构简单的辅助电路,实现了主开关的零电压软开通和零电流软关断.逆变器主开关采用金属氧化物半导体场效应晶体管（Metal Oxide Semiconductor Field Effect Transistor,MOSFET）或者绝缘栅双极型晶体管（Insulated Gate Bipolar Transistor,IGBT）时,都能实现无损耗切换,解决了MOSFET内部结电容造成的容性开通损耗问题和IGBT拖尾电流造成的关断损耗问题.分析了电路的工作过程,实验结果表明开关器件完成了软切换.因此,该拓扑结构对于提高逆变器的性能具有重要意义.     

高效率单相全桥零电流开关谐振极逆变器

为改善单相全桥逆变器的效率,提出了一种新型高效率单相全桥零电流开关谐振极逆变器拓扑结构.在桥臂上的辅助谐振电路参与换流的过程中,逆变器的开关器件可实现零电流软关断.当开关器件为绝缘栅双极型晶体管(Insulated Gate Bipolar Transistor,IGBT)时,IGBT实现零电流软关断可使其拖尾电流导致的关断损耗等于零,有利于改善以IGBT作为开关器件的单相全桥逆变器的效率.分析了电路工作流程.实验结果显示出开关器件完成了零电流软切换动作.因此,对于研发以IGBT作为开关器件的高效率单相全桥逆变器,该拓扑结构具有一定的参考价值.     

具有单辅助开关的高效率单相全桥谐振极逆变器

为改善单相全桥逆变器的效率,提出了一种高效率单相全桥谐振极软开关逆变器拓扑结构,其辅助电路与逆变器桥臂相连,且只含有1个辅助开关和少量无源器件.在逆变器工作过程中,主开关和辅助开关都能实现软切换,通过降低开关损耗来实现逆变器高效率运行.文中分析了电路工作过程,实验结果表明开关器件实现了软开关,这为进一步研发高性能的实用新型单相全桥软开关逆变器奠定了技术基础.     

中小功率三相高频节能型谐振直流环节逆变器

为使中小功率三相逆变器实现在高开关频率下的节能运行,首次提出了一种新型三相谐振直流环节逆变器拓扑结构.设置在逆变器直流环节的辅助电路参与换流过程时,桥臂输入端的直流环节电压能周期性形成零电压状态,主开关和辅助开关都能完成零电压软切换.在高频金属氧化物半导体场效应晶体管（Metal Oxide Semiconductor Field Effect Transistor,MOSFET）作为该逆变器的开关器件时,实现零电压软切换能消除MOSFET的容性开通损耗,有利于优化逆变器效率.文中分析了电路的工作流程.2.5kW样机上的实验结果表明开关器件都处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率三相逆变器具有参考价值.     

具有单辅助开关的谐振直流环节逆变器

为实现一种结构简单、控制方便、高效率、高功率密度的逆变器,提出了一种新型谐振直流环节软开关逆变器的拓扑结构。通过在传统硬开关逆变器的直流环节添加辅助谐振单元,使直流母线电压周期性地归零,可以实现逆变桥主开关器件的零电压开关,而且辅助开关器件可以实现零电流开通和零电压关断。此外,其辅助谐振单元只有一个辅助开关器件,所以该逆变器控制相对简单,硬件成本低。对其工作原理进行分析,给出不同工作模式下的等效电路图和软开关的实现条件。制作一个1kW的实验样机,通过实验结果验证该软开关逆变器的有效性。     

甚低频固态发射机功率器件分析

甚低频发射机用来给潜艇发信,功率达数百千瓦至数千千瓦,如今可以采用MOSFET和IGBT等固态器件作为大功率开关放大器,但选择MOSFET还是IGBT,设计人员需要做出选择。分析了这两类器件的开关特性及导通特性,比较了它们的工作特点,介绍了一种典型的大功率开关放大器应用电路,讨论了甚低频发射机在选择大功率放大器器件时应考虑的一些条件,如频率、电压、开关时间等。     

节能型单相全桥零电流开关谐振极逆变器

为改善以绝缘栅双极型晶体管（Insulated Gate Bipolar Transistor,IGBT）作为开关器件的单相全桥逆变器的效率,提出了一种节能型单相全桥零电流开关谐振极逆变器,在每个桥臂上分别并联1组辅助电路.在工作过程中,主开关和辅助开关都能完成零电流软切换,可消除IGBT拖尾电流造成的关断损耗.分析了电路工作过程,在2kW样机上的实验结果表明开关器件实现了零电流软切换.因此,该拓扑结构可实现以IGBT作为开关器件的单相全桥逆变器的节能运行.     

新型零电压零电流软开关逆变器的仿真研究

提出一种新型的零电压零电流谐振极型软开关逆变器,可以在主功率器件开通和关断时,同时实现零电压和零电流,因此对于内部电容不能忽略的器件,可减小容性开通损耗,当IGBT作为主功率器件时,也可减小拖尾电流引起的损耗。主功率器件真正做到了无损耗换相。此外,续流二极管的反向恢复损耗被降低到最小,辅助开关也实现了零电流开关。对其工作原理进行分析,给出不同工作模式下的等效电路图。通过仿真结果验证该软开关逆变器的有效性。     

节能型单相全桥谐振极逆变器

单相全桥逆变器处于硬开关状态时,随着开关频率的增大,开关损耗明显增大,影响逆变器效率的提高.为解决这一问题,提出了一种节能型单相全桥谐振极逆变器,在逆变器处于死区状态时,将要开通的主开关并联的谐振电容的电压能减小至零,主开关动作时能完成零电压软切换,双向辅助开关动作时能完成零电流软切换.讨论了电路的工作流程,实验结果表明主开关和辅助开关完成了软切换动作.该单相全桥软开关逆变器可以向高开关频率的场合推广应用.     

高效率单相全桥软开关整流器

单相全桥整流器工作在硬开关状态时,随着开关频率和输出功率的增大,开关损耗会显著增大,影响整流器效率的提高.为解决这一问题,提出了一种单相全桥软开关整流器,在整流器处于死区状态时,将要开通的主开关并联的谐振电容的电压能减小至零,主开关动作时能完成零电压软切换,双向辅助开关动作时能完成零电流软切换.分析了整流器的换流过程,实验结果表明主开关和辅助开关完成了软切换动作.因此,该单相全桥软开关整流器在高开关频率下能实现高效率运行.     

单相全桥三电平节能逆变器

随着开关频率的提高,单相全桥逆变器处于硬开关切换时的开关损耗也会明显增大,将导致逆变器处于低效率运行.为解决这一问题,提出了一种单相全桥三电平节能逆变器.通过设置辅助换流电路,利用谐振使主开关并联的电容的电压下降到零,主开关可实现零电压切换,而且在换流过程中,两组双向辅助开关可分别实现零电压切换和零电流切换.分析了电路的工作状态,实验结果表明主开关和辅助开关都能实现软切换.因此该单相全桥三电平逆变器可实现高效率运行.     

A zero-voltage-switched PWM boost converter with an energyfeedforward auxiliary circuit

A zero-voltage-switched (ZVS) pulsewidth-modulated (PWM) boost converter with an energy feedforward auxiliary circuit is proposed in this paper. The auxiliary circuit, which is a resonant circuit consisting of a switch and passive components, ensures that the converter's main switch and boost diode operate with soft switching. This converter can function with PWM control because the auxiliary resonant circuit operates for a small fraction of the switching cycle. Since the auxiliary circuit is a resonant circuit, the auxiliary switch itself has both a soft turn on and turn off, resulting in reduced switching losses and electromagnetic interference (EMI). This is unlike other proposed ZVS boost converters with auxiliary circuits where the auxiliary switch has a hard turn off. Peak switch stresses are only slightly higher than those found in a conventional PWM boost converter because part of the energy that would otherwise circulate in the auxiliary circuit and drastically increase peak switch stresses is fed to the load. In this paper, the operation of the converter is explained and analyzed, design guidelines are given, and experimental results obtained from a prototype are presented. The proposed converter is found to be about 2%-3% more efficient than the conventional PWM boost converter     

A new family of zero-voltage-transition PWM converters with dual active auxiliary circuits

A new family of active auxiliary circuits that allow the power switch in single switch, pulsewidth modulated converters to operate with zero-voltage switching is proposed in this paper. The main feature of an auxiliary circuit belonging to this family is that the auxiliary switch can operate with a zero-current switching turn-on and turn-off without increasing the peak current stresses of the main switch. This is an improvement over previous proposed auxiliary circuits where either the auxiliary switch operates with a hard turn-off or the circuit itself increases the peak stresses of the main switch. In this paper, the fundamental principles behind the proposed family of active auxiliary circuits are explained. Based on these principles, an example auxiliary circuit is systematically derived and presented along with several other auxiliary circuits belonging to the new family. The operation of a boost converter operating with the example auxiliary circuit is discussed in detail, and general guidelines for the design and implementation of auxiliary circuits belonging to the new family are given. The feasibility of the example auxiliary circuit is confirmed by experimental results obtained from a 500-W, 100-kHz boost converter laboratory prototype.     

辅助电路与主开关并联的单相全桥节能逆变器

为了改善逆变器的性能,提出了一种辅助电路与主开关并联的单相全桥节能逆变器.逆变器采用受限单极式正弦脉宽调制（Sinusoidal Pulse Width Modulation,SPWM）方法,在每个开关周期,只需要控制1个主开关和1个辅助开关的切换,辅助开关可以采用固定占空比控制,而且不需要设定谐振电流阈值来控制辅助开关.在每个开关周期的换流过程中,需要切换的主开关所并联的谐振电容的电压能变化到零,主开关能实现零电压软开通.辅助电路中无器件直接串联在直流母线上,可有效降低辅助电路通态损耗.分析了电路工作原理,实验结果表明主开关和辅助开关都实现了软切换.因此该拓扑能有效降低开关损耗和提高逆变器效率.     

靶场某高可靠系统备用电源自投装置设计

为了提高电源的可靠性,保证靶场设备的不间断供电,研究了一种备用电源自投装置。在介绍其组成结构和工作原理的基础上,对装置的总体设计思想和硬件设计方法进行了详细的描述,主要包括电源插件、主控制器插件、电流和电压采集插件、继电器插件、人机交互插件等关键环节的设计。同时对备用电源自投装置的软件设计方法做了研究,实现了主备电源的快速、可靠切换和简洁的人机界面。最后对该装置的可靠性问题进行了探讨。     

一种新颖的双模态LLC谐振变换器的分析与设计

为了提高LLC谐振变换器的输入电压适应范围,提出了一种新颖的双模态LLC谐振变换器。所提出变换器的隔离变压器原边绕组中设计有一个辅助抽头,使得变压器具有两种工作变比,对应两种工作模态：低输入电压区模态和高输入电压区模态。通过检测输入电压控制高频开关,使得变换器自动选择适应当前输入电压的工作模态。文中给出了所提出变换器的详细工作原理和换流过程分析。为了避免变换器在设定的输入电压切换点附近因模态连续切换而产生的震荡,提出了一种基于电压滞环和模态保持的模态切换策略。最后,研制了一台300W的实验样机,样机输入电压为25V~60V,控制芯片为TMS320F28335,样机实验结果验证了所提出的双模态LLC谐振变换器及其模态切换策略的可行性。     

Analysis, designing, and experimentation of a transformer-assistedPWM zero-voltage switching pole inverter

This paper proposes a transformer-assisted pulsewidth modulation (PWM) zero-voltage switching pole inverter. As the auxiliary-resonant-commutated pole inverter (ARCPI), the proposal guarantees zero-voltage switching of the main switch and zero-current switching of the auxiliary switch, with a small power auxiliary circuit and full PWM capability. In particular, problems outstanding with the ARCPI such as control complexity, auxiliary switch protection, and center-tap potential variation, etc., are solved in the proposal. The commutation process is discussed step by step in the paper. A detailed analysis for the auxiliary circuit with regard to commutation duration/duty-cycle limitation, auxiliary switch peak current/RMS current, resonant capacitor RMS current, as well as pole output voltage loss are presented afterwards. A design methodology for the auxiliary circuit is recommended based on the analysis. The proposal is experimentally verified with a 4.25 kW half-bridge inverter prototype     

Design and analysis of a novel zero-voltage-transition interleaved boost converter for renewable power applications

High-efficiency stepping up operation is an important feature of the converters used in renewable power applications due to the low voltage level of photo-voltaic arrays and fuel cells. Decreasing the switching losses of the converters is an effective solution for increasing the converter efficiency, especially in high-power applications. This article presents a novel zero-voltage-transition (ZVT) interleaved dc–dc boost converter that can be used in renewable power sources to reduce switching losses. The auxiliary circuit used in the proposed converter is composed of only one auxiliary switch and a minimum number of passive components without an important increase in the cost and complexity. The main advantage of the proposed converter is that it not only provides ZVT in the boost switches but also provides soft switching in the auxiliary switch. Another advantage of the proposed topology is that the semiconductor devices used in the converter do not have any additional voltage or current stresses. Also, it has a simple structure, low cost and ease of control. In this article, a detailed steady-state analysis of the proposed converter is presented. The theoretical analysis is verified via simulation and experimental studies which are in very good agreement.