灵活直流环节型全软开关逆变器

本文提出了灵活直流环节型全软开关逆变器.其主要贡献如下:(1)给出了以Buck电路为直流环节的全软开关逆变器;(2)给出了最小电压、电流应力的全软开关Buck型DC-DC变换器的理论分析;(3)给出了这种逆变器的控制策略.仿真结果和实验结果(2.7kW)证明了这个电路优于谐振型直流环节型逆变器.     

一种改进型ZVS-Boost电路的研究

对几种常见的基于软开关技术的PFC电路的拓扑结构、工作原理和控制方法进行了分析,指出了各自优缺点及适用场合。研究了ZVS-Boost软开关PFC电路的基本结构、工作原理及软开关实现原理,在此基础上提出了一种改进型ZVS-Boost电路。     

一种新型零电流PWM Buck开关电路的设计

提出一种新型零电流开关PWM Buck电路,对其拓扑结构和工作原理进行了详细分析,仿真结果证明该电路中所有的开关管和二极管均能在软开关条件下完成导通和关断,且具有很小的电流应力,能有效解决IGBT关断时存在的"拖尾电流"问题.     

组合软开关功率变换器的理论和应用

在吸收技术和谐振式软开关技术的基础上提出了组合软开关功率变换器的理论,并将此理论应用到各种变换器,获得了四种组合软开关功率拓扑.在此基础上具体讨论一实用的单相全桥组合软开关逆变电路.该电路结构简单,控制容易.实验结果证明了理论分析的正确性.     

一种DC-DC开关电源的新颖软启动电路设计

提出了一种基于CMOS工艺的新颖软启动电路,该电路利用限流和数字软启技术,实现了输出电压快速、稳定软启,有效抑制了DC-DC开关电源启动过程中所产生的浪涌电流和输出电压过冲.该电路可方便地集成于DC-DC开关电源内部,无需软启动引脚和外接软启动电容,有利于减小封装尺寸和应用电路板空间及降低成本.该软启动电路已经集成到一款Buck型PWM开关控制器当中.试验结果显示,在输出电容等于300μF,空载或带载的情况下,启动过程都非常平稳,电感电流稳定,输出电压上升平滑无过冲,启动时间小于300μs.     

大功率BUCK变换器电压电流尖峰的分析及抑制措施

在大功率Buck变换器中电路工作于高频开关状态,由于实际线路的寄生参数和器件的非理想特性的影响,开关器件两端会出现过高的电压和电流尖峰,严重地降低了电路的可靠性。本文详细分析了两种尖峰产生的原因和危害,有针对性地提出了几种RCL缓冲电路,并给出了电路各参数的分析和设计方法。仿真和使用结果证明了该缓冲电路具有良好的软开关效果,对于主开关管的电压尖峰和电流尖峰具有较强的抑制作用。     

大功率BUCK 变换器电压电流尖峰的分析及抑制措施y

摘要: 在大功率Buck 变换器中电路工作于高频开关状态, 由于实际线路的寄生参数和器件的非理想特性的影响, 开关器件两端会出现过高的电压和电流尖峰, 严重地降低了电路的可靠性。本文详细分析了两种尖峰产生的原因 和危害, 有针对性地提出了几种RCL 缓冲电路, 并给出了电路各参数的分析和设计方法。仿真和使用结果证明了 该缓冲电路具有良好的软开关效果, 对于主开关管的电压尖峰和电流尖峰具有较强的抑制作用。     

基于有效占空比的ZVZCS全桥变换器建模与仿真

分析了零电压-零电流开关(ZVZCS)全桥脉宽调制(PWM)变换器的工作原理,引入变压器副边电压有效占空比的概念并考虑电路元件的寄生参数,在Buck变换器的PWM开关等效模型的基础上,建立了ZVZCS全桥软开关变换器的小信号等效模型,该方法通用于任何可以计算出有效占空比的全桥变换器.通过对小信号传递函数的幅频和相频特性...     

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.     

双向Buck/Boost变换器的教学探析

本文针对现有“电力电子技术”相关教材中存在的对双向变换器的分析不完善和各知识点之间缺乏联系等问题,探析了双向Buck/Boost变换器的拓扑生成原理,并且详细分析了变换器运行于电感电流过零模式下实现零电压开关的具体过程,并推导出了软开关的实现条件。本文有助于学生理解并加深双向变换器与基本Buck和Boost变换器之间的联系和差别,并了解软开关技术在基本变换器中的应用,具有一定的教学指导意义。     

A new ZVT-PWM DC-DC converter

In this paper, a new active snubber cell that overcomes most of the drawbacks of the normal "zero voltage transition-pulse width modulation" (ZVT-PWM) converter is proposed to contrive a new family of ZVT-PWM converters. A converter with the proposed snubber cell can also operate at light load conditions. All of the semiconductor devices in this converter are turned on and off under exact or near zero voltage switching (ZVS) and/or zero current switching (ZCS). No additional voltage and current stresses on the main switch and main diode occur. Also, the auxiliary switch and auxiliary diodes are subjected to voltage and current values at allowable levels. Moreover, the converter has a simple structure, low cost, and ease of control. A ZVT-PWM boost converter equipped with the proposed snubber cell is analyzed in detail. The predicted operation principles and theoretical analysis of the presented converter are verified with a prototype of a 2 kW and 50 kHz PWM boost converter with insulated gate bipolar transistor (IGBT). In this study, a design procedure of the proposed active snubber cell is also presented. Additionally, at full output power in the proposed soft switching converter, the main switch loss is about 27% and the total circuit loss is about 36% of that in its counterpart hard switching converter, and so the overall efficiency, which is about 91% in the hard switching case, increases to about 97%     

Analysis and passivity-based control of zero-voltage-transition PWM converters

A zero-voltage-transition pulse-width modulation (ZVT-PWM) converter composed of a conventional PWM circuit and a resonant tank to achieve zero-voltage switching, resulting in low voltage and current stresses and zero capacitive turn-on losses. In this paper, the analysis and passivity-based control of the ZVT-PWM buck converter are presented. A generalized state space average model of the ZVT-PWM buck converter is derived. The controller design is carried out using the derived model and follows the "energy shaping plus damping injection" ideas of the passivity-based approach. Both direct and indirect output voltage regulation schemes are addressed. Simulation results are presented to illustrate the features of the proposed controllers.     

ZVT-PWM AC-DC boost converter with ZCS auxiliary circuit

A low conduction loss, low-cost zero-voltage-transition-pulsewidth modulation (ZVT-PWM) boost converter with a zero current switching (ZCS) auxiliary circuit is developed to achieve high-conversion-efficiency operation. The unique locations of the resonant capacitor and inductor ensure that low switching stress and commutation losses are obtained in this converter. It is very suitable for high power-factor-correction pre-regulators     

一种基于LM3150 Buck型开关电源设计

Buck型开关稳压电源在现代电子设备中应用广泛,通过研究Buck型变换器的工作原理,介绍了采用LM3150为电源芯片的Buck型开关电源的设计。借助于WEBENCH电源设计工具选择合适的外围元件,实现效率、成本、面积和开关频率的优化。通过仿真表明该电源稳定性好,转换效率高,可以广泛应用于便携设备中。     

Novel ZVT-PWM converters with active snubbers

An active snubber cell is proposed to contrive zero-voltage-transition (ZVT) pulsewidth-modulated (ZVT-PWM) converters. Except for the auxiliary switch, all active and passive semiconductor devices in a ZVT-PWM converter operate at zero-voltage-switching (ZVS) turn on and turn off. The auxiliary switch operates at ZVS turn off and near zero current-switching (ZCS) turn on. An analytical study on a boost ZVT-PWM converter with the proposed active snubber cell is presented in detail. A 750 W 80 kHz prototype of the boost ZVT-PWM converter has been built in the laboratory to experimentally verify the analysis. Six basic ZVT-PWM converters can be easily created by attaching the proposed active snubber cells to conventional PWM converters. A detailed design procedure of the proposed active snubber cell is also presented in this paper     

ZVT-PWM boost converter for unity power factor applications

A new single-phase ZVT-PWM boost converter with an active snubber is proposed to achieve unity power factor operations for a wide load range. The unique location of the resonant inductor and capacitor ensures that low switching stress and commutation losses are obtained in the converter. The proposed converter is suitable for high power factor correctors     

A soft-switching mode rectifier with power factor correction andhigh frequency transformer link

This paper presents a soft-switching mode rectifier (SSMR) consisting of a power factor correction zero-voltage-transition-pulse-width-modulated (PFC ZVT-PWM) converter and a high-frequency transformer-coupled DC/DC zero voltage switching clamped voltage (ZVS-CV) converter. An easily implemented ZVT soft-switching mechanism is developed to reduce the switching losses and stresses of the power switches in the PFC ZVT-PWM converter. The operations of the proposed SSMR in various modes are analyzed in detail and the associated governed equations are derived. Then accordingly, a quantitative design procedure is developed to find the values of soft-switching circuit components. In the control aspect, the dynamic model of the SSMR is derived and a current waveform controller is designed, such that sinusoidal line current with low harmonics and near unity power factor is obtained. Under this condition, a voltage controller is also designed for yielding good DC output voltage control characteristics. Validity of the designed SSMR is verified experimentally     

基于峰值电流模控制的浮动栅驱动电路

设计了一种基于峰值电流模控制的浮动栅驱动电路,包括浮动栅宽电路和浮动栅压电路。电感电流的峰值由误差放大器的输出电压决定,不需要额外的负载电流信息进行浮动栅控制。可以根据负载电流的大小自适应调节功率管的栅宽和栅压,使效率得到优化。仿真结果表明,在1 MHz开关频率、5 V输入、0.8 V输出的双N管Buck变换器中,采用浮动栅驱动控制的Buck变换器与普通的Buck变换器相比,在轻载情况下最多可达到10%的效率提升。     

集成双层平面电感的单片DC/DC转换器设计

采用0.35μm标准CMOS工艺设计了3.3V/1.5V单片低压Buck转换器,开关频率为150MHz.本文采用了电压型脉宽调制的反馈控制模式,克服了频率提高所带来的转换器系统不稳定问题.对双层平面螺旋电感进行了设计与优化,获得品质因数2.6,电感值28nH的双层平面电感.模拟结果表明,对应于不同输入电压或不同负载,转换器系统工作稳定,输入调整率-40dB,输出调整率-60dB.输出电压纹波平均值可以控制在额定值75mV,转换效率71%.