矩阵变换器的换流研究

本文讨论了矩阵变换器的换流特点，详细分析了矩阵变换器基于负载电流、基于电源电压以及改进型的基于电源电压三种换流策略的换流方法，对这三种换流方法进行比较，最后对改进型基于电源电压的换流策略采用MATLAB／SIMULINK进行仿真，给出具体的仿真电路和波形，证明了改进型基于电源电压换流策略的正确性。     

一种基于ACOT的高效降压型DC/DC变换器

采用自适应恒定导通时间(Adaptive Constant On-Time,ACOT)控制模式,设计了一种高效的降压型DC/DC变换器。该电路结构简单,无需进行环路补偿,具有瞬态响应快、在全负载段内转换效率高、频率集中等优点。基于0.6μm 16VCD工艺,对设计的降压型DC/DC变换器进行仿真验证。结果表明,该变换器在轻载下的效率高于83%;在全负载范围内,最高效率达到97%;系统的工作频率不随输入电源电压变化,具有快速的瞬态响应速度。     

新型雷达固态收发模块电源的设计

为了达到雷达固态收发模块对电源高效变换的要求,提出了一种基于谐振技术的新型电源变换器设计方案。电源采用两级功率变换,前级为隔离型变换器,完成输入功率因数校正(PFC),起到降压、隔离及初步稳压的作用。后级为多路非隔离降压型(BUCK)谐振变换器,实现输出电压的进一步的调节。后级的BUCK谐振变换器利用电感和电容谐振实现了功率管的零电流(ZCS)和零电压(ZVS) 开关。在高频化的同时降低了开关损耗,同时电路工作原理简单,易于实现和控制。设计方案对该电路工作原理和特性进行了详细分析,并给出固态收发模块电源主要参数设计及电源工作的部分波形。     

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。     

一种新的应用于降压式DC-DC变换器电流采样电路的设计

在分析了传统的应用于大负载电流降压式DC-DC变换器电流采样电路主要缺点的基础上,提出一种新的应用于降压式DC-DC变换器的电流采样电路。该方法通过一个电阻电容网络来消除电感寄生电阻的影响,并利用开关电容积分器来实现降压式DC-DC变换器的电流采样,在Chartered 0.35μm CMOS工艺下实现该电路并流片验证。最终的测试结果显示,提出的电流采样电路实现了对降压式DC-DC变换器精确的电流采样。     

一种新型DC/AC变换器在光伏微电网中的应用

提出了一种新颖的特别适用于太阳能与风能发电电力转换的单级单相升降压变换器,变换器四个功率开关管可以全部采用IGBT,其中二个也可以由可控硅替换,无需其它的任何额外开关。因此该变换器电路在实现高性能的同时降低了变换器电路成本费用。对提出的变换器进行了理论分析和建模,该电路设计理论经过光伏应用实验验证了其可行性和实用性。     

低电压大电流变换器电路技术

介绍抽头电感器方式降压型变换器、推娩式正向变换器和两段式DC/DC变换器所采用的电路技术。     

零电流开关准谐振变换器及UC3960的应用

本文详细分析了零电流开关关准谐振降压变换器和半桥变换器的基本工作过程及设计方法，详细介绍了零电流开关准谐振变换器专用控制电路ＵＣ３９６０的电气参数和应用电路，最后给出了１５０Ｗ零电流开关准谐振开关稳压器实例，对于研究零电流开关准谐振变器具有一定的指导作用     

一种实用的大功率全桥ZVZCS变换器的设计

针对当前大功率的全桥ZVZCS变换器存在功耗过高,实用率不高的问题,提出一种实用的电路拓扑结构,并对该电路拓扑进行了简单的分析。该变换器超前管采用MOSFET,实现了零电压开通和关断,滞后管采用IGBT,实现了零电流开通和关断。对变换器主电路各参数进行选定后,通过采集的相关波形,验证了设计的变换器的正确性,将该变换器应用在电力操作电源上运行,性能优良,满足了市场要求。     

新型RCD箝位单端正激式变换器仿真研究

本文结合同步整流管驱动技术在低压大电流功率变换器中的应用，在传统RCD箝位单端正激式I变换器的基础上，提出了一种全新的RCD箝位正激变换器，解决了死区时间驱动问题，大大提高了整流电路的变换效率和整个变换器的效率。     

Simple topologies of PWM AC-AC converters

This letter proposes a new family of simple topologies of PWM AC-AC converters with minimal switches. With extension from the basic DC-DC converters, a series of AC-AC converters such as buck, boost, buck-boost, Cuk, and isolated converters are obtained. By PWM duty ratio control, they become a "solid-state transformer" with a continuously variable turns ratio. All the proposed AC-AC converters in this paper employ only two switches. Compared to the existing circuits that use six switches or more, they can reduce cost and improve reliability. The operating principle and control method of the proposed topologies are presented. Analysis and simulation results are given using the Cuk AC-AC converter as an example. The analysis can be easily extended to other converters of the proposed family.     

Matrix converter controlled with the direct transfer function approach: analysis,modelling and simulation

Power electronics is an emerging technology. New power circuits are invented and have to be introduced into the power electronics curriculum. One of the interesting new circuits is the matrix converter (MC), and this paper analyses its working principles. A simple model is proposed to represent the power circuit, including the input filter. The power semiconductors are modelled as ideal bidirectional switches and the MC is controlled using a direct transfer function approach. The modulation strategy of the converter is explained in a complete and clear form. The commutation problem of two switches and the generation of overvoltages are clarified. The paper also includes a soft-switching commutation method that allows for a safe commutation of the switches. Finally a complete simulation scheme, using Matlab®–Simulink®, is discussed.     

A high-power high-frequency ZCS-ZVS-PWM buck converter using afeedback resonant circuit

This paper presents a buck DC-to-DC power converter using a novel lossless commutation cell for high switching frequency and high power operation. The proposed cell consists of a main and auxiliary switches, with ZVS and ZCS switching characteristics, respectively. The power converter control using this cell is realized by the PWM technique, with constant switching frequency operation. The complete operation principles, theoretical analysis, relevant equations, state-space phase, simulation and experimental results for the buck converter are presented     

一种车用恒流/恒压模式的四开关Buck-Boost变换器控制策略研究

对一种车用恒流/恒压模式的四开关Buck-Boost变换器的控制策略进行了研究。在输入输出电压接近时引入Buck-Boost模式,从而在不同输入输出电压大小关系下,通过检测功率管占空比大小,实现Buck模式、Boost模式和Buck-Boost模式之间的平滑切换,提高了系统的稳定性。通过设计最大值选择电路,使变换器在充电应用中自动从恒流模式切换到恒压模式,模式切换平滑稳定。仿真结果表明,在24 V输出电压下,变换器从Buck模式切换到Buck-Boost模式时,输出电压下冲为9.2 mV,变换器从Boost模式切换到Buck-Boost模式时,输出电压下冲为92 mV。变换器在Buck模式与Boost模式下均能实现恒流/恒压模式的自动平滑切换。     

基于滑模控制的DC-DC降压变换器实验平台

为了实现DC-DC降压变换器的高精度控制,设计了一种基于滑模控制的输出电压调节器。首先根据DC-DC降压变换器的工作原理建立了系统的动态模型;接着利用转换后的受扰动态模型设计了滑模控制器,同时基于李雅普诺夫函数证明了闭环系统的稳定性;最后使用Matlab/Simulink软件和DC-DC降压变换器硬件电路搭建了实验测试平台。测试结果表明与传统的PID控制方法相比,DC-DC降压变换器系统在所设计的滑模控制器的作用下可以获得更快的动态性能与更强的扰动抑制能力。该实验平台不仅有利于大学生理解和掌握滑模控制理论,还可以提高大学生的工程应用能力。     

Switching technique for current-controlled AC-to-AC converters

The AC-to-AC converter called the matrix converter is very simple in structure and has powerful controllability. However, there are few practical applications, particularly in power electronics fields. The major reasons largely lie in the commutation problem and complexity of the control circuit. This paper proposes a novel commutation technique which is very simple to implement. This commutation scheme allows the deadtime to avoid current spikes of nonideal switches and, at the same time, establishes a current path of the inductive load to avoid voltage spikes. A switching technique of the matrix converter using a space-vector-modulation (SVM) based hysteresis current controller (HCC) is also proposed. The switching technique is implemented without any computational burden and is controlled with a simple control circuit. This technique utilizes advantages of the HCC and SVM technique. Simulation and experimental results obtained on a 5 kW single-phase AC chopper and an 11 kW three-phase to three-phase matrix converter are discussed     

超快速加载Buck变换器设计

为了提高VRM的加载响应速度,该文分析了传统Buck变换器的最优加载过程,并基于传统Buck变换器提出了双输入Buck变换器电路方案,说明了其稳态工作过程和加载运行过程,以最优加载阈值为依据给出了附加电源的切换条件,并做了仿真对比研究.仿真和试验结果表明双输入Buck变换器较传统Buck变换器具有更快加载响应速度和更小输出电压跌落,且结构简单,易于设计和实现,适用于VRM主电路.     

A new technique for parallel connection of commutation cells:analysis, design, and experimentation

A new technique useful for the parallel connection of commutation cells is introduced in this paper. It consists of using small inductances in order to ensure dynamic and static sharing of the commutated current among the different switches. The operating principle, theoretical analysis and design procedure are presented. Experimental results, obtained from a 400-W buck power converter prototype using two commutation cells, have been used to validate the theoretical analysis and demonstrate the effectiveness of the proposed technique. Several experiments have been also accomplished to clear up the advantages of this new technique in comparison to the conventional one. Results from a three-cell buck DC-DC power converter delivering 4.5 kW are also presented, revealing a balanced current sharing among cells and an excellent dynamic behavior, as foreseen in the theoretical analysis     

Buck型变换器电路结构及其演化过程

文中论述了基于Buck型变换器的DC-DC、DC-AC、AC-DC和AC-AC变换器电路结构及其演化过程,给出了各类变换器的电路-拓扑实例和原理试验结果。理论分析和原理试验结果表明,Buck型变换器在中大容量的DC—DC、DC-AC、AC-DC和AC-AC电能变换中具有重要的应用价值。     

A feedback loop regulated bootstrap driver circuit with improved drive capability for high voltage buck DC–DC converter

A novel bootstrap driver circuit applied to high voltage buck DC–DC converter is proposed. The gate driver voltage of the high side switch is regulated by a feedback loop to obtain accurate and stable bootstrapped voltage. The charging current of bootstrap capacitor is provided by the input power of the DC–DC converter directly instead of internal low voltage power source, so larger driver capability of the proposed circuit can be achieved. The bootstrap driver circuit starts to charge the bootstrap capacitor before the switch node SW drop to zero voltage at high-side switch off-time. Thus inadequate bootstrap voltage is avoided. The proposed circuit has been implemented in a high voltage buck DC–DC converter with 0.6 µm 40 V CDMOS process. The experimental results show that the bootstrap driver circuit provides 5 V stable bootstrap voltage with higher drive capability to drive high side switch. The proposed circuit is suitable for high voltage, large current buck DC–DC converter.