SiC SBDs selection method based on loss analysis of boost converter

Silicon carbide schottky barrier diodes (SiC SBDs) have much better characteristic than Si PiN diode in high voltage applications because SiC SBDs do not have recovery effect. However, simple replacing is not the most effective way. In a boost converter, the power loss caused by the SiC SBD can be divided into the conduction loss of the SiC SBD and the loss caused by the energy stored in the junction capacitance of the SiC SBD. Therefore analysis of not only the conduction loss but also the loss caused by the energy stored in the junction capacitance of the SiC SBD can realize the SiC SBD selection to improve the efficiency of the boost converter. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于无源控制的车用双管升压变换器研究

新能源汽车能处于正确的电压级别下安全可靠地运行,DC/DC变换器发挥着重要作用,针对其现有控制方法多为线性控制,难以应对负载与输入电压参数多变的情况的问题;在非线性控制既无源控制的基础上引入了PI阻抗反馈补偿环路的概念,提出了一种PI阻抗补偿无源控制策略。为证明其优越性,与现有方法进行了比较。并针对负载与输入电压参数变化情况进行了模拟仿真,结果表明,该策略在输入电压跌落8 V后,仅产生了2 V的波动;负载突变为初值的一半时,仅用了不到0.01 s便重新抬升至给定电压值。由仿真结果可得,该策略不仅响应速度快、不会产生超调现象,而且在负载和输入电压发生较大变化的情况下,仍能很好的抵御外部干扰并保持输出电压的稳定性和优秀的电压纹波抑制效果,具有良好的鲁棒性。     

基于电流源驱动的MOSFET管损耗模型及分析

对于以电压源方式驱动功率MOSFET管,随着开关频率的提高,其开关损耗将显著增加。以此为切入点对电流源驱动功率MOSFET管进行了研究。在对电流源驱动MOSFET管原理性分析的基础上,通过详细地分析功率MOSFET管的开关过程,建立MOSFET管开关损耗模型,求解得到漏极电流、漏源电压与栅源电压之间关系,证明了电流源驱动在减少开关时间和开关损耗上的优越性。在开关频率为1 MHz、输入电压为12 V、输出电压和电流分别为1.3 V和25 A的低压大电流实验平台上进行了验证,实验结果证明了所提出的MOSFET管损耗模型的正确性。     

MOSFET谐振门极驱动电路研究综述

谐振门极驱动电路能够减小高频下MOSFET的驱动损耗。首先介绍了传统电压源驱动及其存在的诸多问题,引出谐振驱动技术。综述了目前现有的谐振门极驱动电路的拓扑结构,并分为电流源型、谐振型和耦合电感型三大类。对于电流源型和谐振型,分别介绍较早提出的拓扑结构及其优缺点,并与后期发展的各种拓扑作对比分析。耦合电感型是在电流源型或谐振型中加入耦合电感来传递能量,这也增加了拓扑的复杂度。考虑谐振门极驱动电路的复杂程度,将拓扑元器件集成到一个芯片中以达到优化。     

基于DSP双管并联升压斩波电路设计

介绍了一种适合大功率的并联升压斩波电路结构以及该电路的原理与工作特性,分析了基于DSP芯片的升压型电路,设计了硬件电路以及编写软件程序。该方案电路简单,可靠性高,转换效率高,经过实验测试,验证了该电路的优点和工程应用价值。     

一种用于功率MOSFET的谐振栅极驱动电路

介绍了一种用于功率MOSFET的谐振栅极驱动电路。该电路通过循环储存在栅极电容中的能量来实现减少驱动功率损耗的目的 ,从而保证了此驱动电路可以在较高的频率下工作。通过实验 ,证明了这种电路的正确性和实用性     

Analysis of high-power factor AC-DC boost converter

This paper presents analysis of a high-power factor ac-dc converter with a boost converter operating in the discontinuous conduction mode (DCM) and the critical conduction mode (CRM). The converter can be expressed by a nonlinear differential equation for each mode. The equation in DCM is solved analytically by separating its variable (output voltage) into two terms of a ripple component and a direct component, and by linearizing the equation for the ripple component. On the other hand, the equation in CRM can be solved analytically. Furthermore, the source current waveform of the converter is expanded into the Fourier series. As a result, the output voltage, its ripple and the power factor of the converter in DCM and CRM are derived as a function of the circuit parameters, respectively, and verified experimentally. These equations exhibit clearly the effect of each circuit parameter of the converter and the difference between the converter in DCM and in CRM. The converter operating in CRM produces sinusoidal ac current with unity power factor.     

Small‐signal analysis of interleaved dual boost converter

This paper presents a systematic development of steady‐state, small‐signal models of interleaved dual boost converter operating in a continuous current mode. These models are derived by employing the well‐known signal flow graph method. This signal flow graph approach provides a means to directly translate the switching converter into its equivalent graphic model, from which a complete behaviour of the converter can easily be studied. Steady‐state performance, small‐signal characteristic transfer functions are derived using Mason's gain formula. The bode plots of audiosusceptibility, input impedance, output impedance, and control‐to‐output transfer functions are determined and illustrated using MATLAB for different values of load resistances, duty ratios. Small‐signal frequency responses obtained from the signal flow graph method are validated with PSPICE simulator results. To validate the signal flow graph modelling equations, sample steady‐state experimental results are provided. Copyright © 2001 John Wiley & Sons, Ltd.     

The stability of a chaotic PWM boost converter

A novel chaotic pulse‐width‐modulation (PWM) boost converter has been previously proposed to reduce electromagnetic interference (EMI) in DC–DC converters, where the circuit design and simulations have been conducted, but the problems such as the mean value estimation of state variables for circuit parameter design, the ripple estimation of the input current and the stability analysis have been remained to be addressed in this paper. Here, a mean value estimation method is first proposed, which is used to estimate the mean values of state variables of chaotic PWM boost converters for facilitating the circuit parameter design and selection of circuit components. Although ripples are slightly increased, caused by adopting chaotic carriers, the DC–DC converter with reduced EMI is still stable under the chaotic PWM control. This work provides a theoretic verification of the effectiveness and practicability of the proposed chaotic PWM DC–DC converters. Copyright © 2010 John Wiley & Sons, Ltd.     

一种输入电流连续的新型高增益DC-DC升压变换器

高增益DC-DC变换器正越来越多地应用于太阳能光伏或其他可再生能源发电系统。良好的稳态和动态性能以及更高的效率,是为上述应用选取变换器的先决条件。为此,提出一种高增益DC-DC升压变换器。首先,详细阐述了该新型变换器的拓扑结构与工作原理,在此基础上,对其电路参数进行了设计。然后,将所提变换器与最近提出的其他类似变换器在各种性能参数上进行了比较。最后,采用Matlab软件建立了系统仿真模型,并研制了实验样机。仿真和实验结果验证了理论分析的正确性。所提变换器只使用一个功率开关,具有连续的输入电流,同时能够降低开关器件间的电压应力。占空比的工作范围更宽,并且在较低的占空比下可以获得较高的电压增益。输入电流连续是DC-DC变换器的一个理想特性,所提变换器非常适合太阳能、光伏应用。     

Experimental evaluation of active power factor correction techniques in a single-phase AC-DC boost converter

The increasing need to improve power quality with the reduction of the harmonic content of current and voltage waveforms has been intensively analyzed in several studies, thus motivating the proposal of many high power factor rectifiers based on the classic converters such as boost and buck-boost. Moreover, distinct control techniques have also been proposed due to the commercial availability of integrated circuits (ICs) dedicated to impose sinusoidal input currents in switch-mode power supplies (SMPSs). The boost converter operating in continuous conduction mode (CCM) is by far the most traditional choice for this purpose due to circuit simplicity and low electromagnetic interference (EMI) levels. Within this context, this work analyzes some of the most important control techniques used in power factor correction (PFC). The performance of a single-phase boost converter using peak current mode control (PCMC), average current mode control (ACMC), and one cycle control (OCC) is evaluated experimentally in detail. A comprehensive analysis of key aspects such as the input current waveform and respective harmonic content, dc output voltage, and dynamic response of the converter is also presented.     

A novel active‐clamp zero‐voltage‐switching buck‐boost converter

An active‐clamp zero‐voltage‐switching (ZVS) buck‐boost converter is proposed in this paper to improve the performance of converter in light load condition. By employing a small resonant inductor, the ZVS range of switches could be adjusted to very light load condition. Moreover, 2 clamping capacitors are added in the converter to eliminate the voltage spike on the switches during transition. The operating principle of the proposed converter is analyzed, and the optimal design guide for full range ZVS is also provided. A 60‐W output prototype is experimentally built and tested in laboratory to verify the feasibility of proposed converter. The measured results show the critical ZVS operation of power switches at 1 and 0.7‐W output power for buck and boost mode, respectively. The peak conversion efficiency is up to 92.3%.     

二次型CCM Boost变换器能量传输模式

为了分析二次型CCM Boost变换器输出电压纹波特性,研究其能量传输模式.根据电感电流谷值与负载输出电流的关系,分析二次型CCM Boost变换器在开关管关断期间的能量传输模式,即完全电感供能模式(CISM)和不完全电感供能模式(IISM).分析在忽略输出电容等效串联电阻和存在输出电容等效串联电阻两种情况下,工作于CISM和IISM模式的二次型CCM Boost变换器的输出电压纹波特性,得出CISM与IISM模式的临界电感值和临界工作条件.分析结果表明,当二次型CCM Boost变换器工作于CISM模式,且忽略输出电容等效串联电阻时,输出电压纹波仅由开关管导通期间输出电容电压的下降幅度决定,与电感无关;而当存在输出电容等效串联电阻时,工作于CISM模式比IISM模式具有更小的输出电压纹波.实验结果验证了理论分析的正确性.     

减少MOSFET开通损耗的输出电容优化曲线的研究

介绍了利用输出电容的电荷存储效应来分析由于寄生输出电容的存在给MOSFET器件动态开通时带来的附加损耗，并进一步介绍了能够减少这部分损耗的输出电容曲线的优化过程。     

An extendable single-switch n-cell boost converter with high voltage gain and low components stress for renewable energy

Boost converters have been widely employed in industrial applications, and cascading boost converters is a mature technique to realize ultrahigh voltage gains. However, the cascade structure inevitably increases the voltage stress of buffer capacitors, resulting in high costs and low energy efficiency. Targeting this issue, in this study, we propose a novel extendable single-switch n-cell boost converter (ESSnB), which utilizes the same number of components as the conventional positive output boost converter, but has lower buffer voltage stresses. Simulation and experimentation are conducted in this study, which verify the effectiveness and superiority of the proposed ESSnB over conventional boost converters.     

基于Matlab的功率MOSFET建模

针对Matlab/PSB中MOSFET的理想开关模型的不足,提出了一种以功率MOSFET输出特性曲线为核心建立其特性模型的方法。该模型不但能精确模拟稳态的各种特性,也能够描述开关瞬态的过程。将模型应用于固态开关的仿真中,仿真结果与实验波形证明了该模型的正确性与准确性。     

Boost矩阵变换器的离散滑模控制策略

针对目前矩阵变换器存在电压传输比低的缺陷,在对拓扑结构的基本构成及其工作原理分析基础上,提出一种新型的称为Boost矩阵变换器的电路拓扑结构.推导了其电压传输比与占空比之间函数关系的解析表达式,阐述了所采用的离散滑模控制策略的设计方法,并通过仿真对其有效性和可行性进行了验证.结果表明,该拓扑结构能实现输出电压和频率在一定范围内的任意调节,其电压传输比既可大于1,也可小于1,且直接输出高品质的正弦波而无需滤波环节,从而有效解决了传统矩阵变换器电压传输比低的难题.     

Three‐stage inrush current suppressed circuit for BCM boost converter

A three‐stage inrush‐current suppression circuit is proposed for the boundary conduction mode boost circuit, which not only can suppress the first inrush current when powered on in the boost topology but also can suppress the secondary inrush current caused by the working of the boost circuit; the inrush current caused by the electromagnetic interference filter can also be suppressed. The simulations are performed to prove the rightness and feasibility of the circuit, and the circuit is used in a 1000‐W two‐stage electronic ballast for the metal halide lamp. In the experiment, the first inrush current is nearly 0 A, and the second inrush current is less than 12 A. Copyright © 2013 John Wiley & Sons, Ltd.     

Harmonic balance‐based control of a boost DC/AC converter

The achievement of step‐up inversion with a boost DC/AC converter requires appropriate periodic references for inductor currents, which have to satisfy ordinary differential equations (ODE) of the Abel type. These are equations with highly unstable solutions for which the existence of periodic solutions remains unproved. Hence, the studies reported so far in this subject obtain periodic output voltages that approximately track the expected profile using different periodic current references that do not exactly satisfy the Abel ODE. However, neither an explanation of why are periodic output voltages still obtained, nor an assessment of the output voltage error is provided. This paper analyzes the effect of using periodic current references in a Lyapunov‐based controlled boost DC/AC converter performing step‐up inversion tasks. It is shown that, for sufficiently accurate current references, the system exhibits asymptotically stable periodic solutions with bounded error. Moreover, the paper propounds the use of Harmonic Balance (HB)‐based techniques to obtain such current references. Simulation and experimental results confirm that this choice yields periodic output voltages with an error that may be lowered using higher HB approximations. Copyright © 2011 John Wiley & Sons, Ltd.     

基于上下续电流的功率变换器故障诊断方法

开关磁阻起动/发电系统中功率变化器是核心部件,其故障将会给系统带来不可估量的影响。针对功率变换器的典型电气故障(上下管的开、短路故障)进行了分析,研究了上下续电流的变化,结合电动状态和发电状态的共同点和不同点,基于上下续电流分别提出了一种在线故障诊断方案,利用上下续电流在一个周期内积分值的变化,来进行判断故障类型和故障位置;同时利用数字化的思想,提取了故障特征系数F'_(AB1)、F'_(AB2)和F'_(A12),利用判断特征系数来进行在线的故障诊断;最后搭建了开关磁阻起动/发电系统的故障诊断模型并分别进行了仿真验证。结果表明:该方案在电动和发电状态都能够实现在线的故障诊断,并且实现了故障验证;与相电流故障诊断相比,大大降低了虚警率。