基于伏秒平衡原理的Buck-Boost变换器分析

针对现有"电力电子技术"教材中普遍存在的对Buck-Boost变换器的分析不完整等问题,本文基于伏秒平衡原理对Buck-Boost变换器进行了全面分析,推导出变换器全范围的输入输出电压关系,电流连续模式(CCM)和断续模式(DCM)的临界工作条件以及电路各参数对电流纹波和电压纹波的影响等。本文一方面有助于更全面深入地理解Buck-Boost变换器的工作原理及特性,另一方面有助于DC-DC变换器分析方法的统一,具有一定的教学指导意义。     

基于多频脉冲序列控制Buck变换器的研究

针对开关变换器双频率控制技术存在的输出电压纹波大、输出功率范围窄等缺点,研究电压型多频率脉冲序列控制方法,该方法通过四组预设控制脉冲,实现开关变换器输出电压的调节。对多脉冲序列控制Buck变换器在电感电流连续导电模式（Continuous Conduction Mode,CCM）和电感电流断续导电模式（Discontinuous Conduction Mode,DCM）下的工作特性进行分析,重点研究了在DCM 模式下Buck变换器多频率控制。最后,分析了DCM Buck变换器工作在稳态时脉冲序列的组合方式,并通过实验验证了理论分析的正确性。     

关于本质安全Boost变换器的探讨

分析Boost变换器工作于连续导电模式（CCM）和不连续导电模式（DCM）时的电感电流,指出当输入电压为最低。负载电阻为最小时,且变换器工作在CCM下的最大电感电流就是该变换器在整个工作范围的最大电感电流。并将其与最小点燃电流相比较作为变换器内部本质安全的判断依据。实验结果验证了理论分析的正确性。     

临界导电模式下PFC储能电容电压及电流分析

针对工作于临界导电模式下(CRM)的功率因数校正器(PFC)的输出储能电容有效值(RMS)电流及其电压纹波,进行了详细的教学推导.对功率因数校正(PFC)和临界导电模式(CRM)进行了简要的介绍,给出了临界导电模式下(CRM)输出储能电容(Bulk Capacitor)的有效值(RMS)电流及其输出电压纹波(Rippl...     

关于本质安全Boost变换器的探讨

分析Boost变换器工作于连续导电模式(CCM)和不连续导电模式(DCM)时的电感电流,指出当输入电压为最低,负栽电阻为最小时,且变换器工作在CCM下的最大电感电流就是该变换器在整个工作范围的最大电感电流,并将其与最小点燃电流相比较作为变换器内部本质安全的判断依据.实验结果验证了理论分析的正确性.     

有LC滤波器的斩波器式电压调节器的比较分析

论文分析讨论了 DC-DC 变换器的三种基本电路(即现在人们熟知的 Buck、Boost、Buck-Boost 变换器——译者)的静态特性。考虑了两种运行模式:电感电流为连续(CCM)和不连续(DCM)运行模式,还考虑了电感的寄生电阻。对三种基本电路进行了理论分析比较,推导了输出-输入电压比公式;给出了电压变换比曲线、最大输出电压随占空比变化曲线等。     

Boost变换器BCM电流自恢复及数字预测纹波控制电路设计

为了解决电感值不准确导致的boost变换器模型偏差,进而不能实现良好的临界导通模式控制问题,提出了一种基于电流自恢复的数字预测纹波控制电路.根据电感电流的纹波特性,该控制器预测开关元件的导通及关断时间,将电感电流控制在临界导通模式.基于电感电流阻尼模型,证明了电感电流具有自动恢复到临界导通模式的特性,因而不需要电流检测...     

连续导电模式下的单电感双输出开关变换器

文章系统地分析了单电感双输出DC—DC变换器结构,采用分时复用原理实现双路输出。由于电感共享,各输出支路间存在着严重的交叉影响。当输出支路严格工作在不连续导电模式（DCM）或伪连续导电模式（PCCM）下,可有效抑制交叉影响。文章首次提出了应用于连续导电模式工作的单电感双输出开关变换器的峰值电流-差模电压控制方法,在连续导电模式（CCM）下实现了几乎没有交叉影响的双路输出。     

基于分数阶Buck-Boost变换器建模与分析

对Buck-Boost变换器应用相关分数阶微积分理论建立基于电感电流连续模式下分数阶数学模型,然后理论分析建立起来的分数阶数学模型.基于改进的分数阶微积分Oustaloup滤波器算法,建立电感电流连续模式下Buck-Boost变换器Matlab/Simulink分数阶仿真模型.最后,分数阶仿真结果与整数阶的结果进行分析比较,验证分数阶数学模型与理论分析的正确性.     

Zeta型电子束焊机高压稳定电源的纹波抑制与稳压

在传统的电子束焊机电源系统中,由于开关电源自身的原因,存在较高的固有高纹波输出电压特点,导致电子束焊机电源系统的输出电压不稳定。为此,采用耦合电感技术,设计了一种Zeta型变换器为主电路的电子束焊机的电源系统,其原理是将耦合电感技术与Zeta型变换器相结合,合理分配Zeta变换器中的两耦合电感的耦合程度来抑制纹波。同时,采用PI控制-前馈控制构成的复合控制器提高电源系统的控制精度和输出稳定精度。PLECS软件仿真结果表明,该系统不仅抑制输出电压纹波效果十分明显,而且还具备输出电压稳压精度高、动态特性好和工作可靠等特点,验证了理论推导的正确性。     

A Single Phase Voltage Regulator Module (VRM) With Stepping Inductance for Fast Transient Response

A single-phase fast transient converter topology with stepping inductance is proposed. The stepping inductance method is implemented by replacing the conventional inductor in a buck converter by two inductors connecting in series. One has large inductance and the other has small inductance. The inductor with small inductance will take over the output inductor during transient load change and speed up dynamic response. In steady state, the large inductance takes over and keeps a substantially small ripple current and minimizes root mean square loss. It is a low cost method applicable to converters with an output inductor. A hardware prototype of a 1.5-V dc-dc buck converter put under a 100-A transient load change has been experimented upon to demonstrate the merit of this approach. It also serves as a voltage regulator module and powers up a modern PC computer system     

Adaptive current-threshold detector for an adaptive on-time Buck converter at light load

The adaptive on-time control technique has been tremendously utilized in DC–DC converters for its fast transient response, easier design and high efficiency at light load. In some applications the output voltage ripple of DC–DC converters has to be maintained within an acceptable level to achieve superior performance, which depends largely on the load current for adaptive on-time buck converters when operating in discontinuous conduction mode. This paper proposes an adaptive current-threshold detection method for reducing the output voltage ripple. An actual detector circuit is presented to implement the method. This circuit monitors the relationship between the peak inductor current and the load current at light load. Then it outputs a logic signal which controls the turn-on time of the main power MOSFET and hence the peak inductor current. Therefore, the magnitude of the output voltage ripple is controlled. The current-threshold detection method has been verified in an adaptive on-time buck converter by simulation and experimental results. The proposed method can also be used in other constant on-time converters.     

A Buck-Derived Topology With Improved Step-Down Transient Performance

The slew rate of the inductor current is limited by the inductance value and the voltage across the inductor. In a buck converter, when the controller is saturated, the voltage across the inductor during a step-up load transient is $V_{rm in}-V_{rm out}$, while during a step-down load transient, it is $-V_{rm out}$. Thus, a buck converter with a large conversion ratio offers asymmetrical step-up and step-down transients. Since the rate of fall of the inductor current is much slower than the rate of rise of the inductor current, the step-down transient lasts longer than the step-up transient for the same change in the load current. The step-down slew rate can be increased by reducing the inductance, but it results in higher inductor current ripple, and hence, higher losses in the power converters. In this paper, we present a novel topology for improving the step-down load transients without reducing the inductance value. The scheme operates only during load transients and restores to the normal operating conditions during steady-state operation. It provides reduced voltage overshoots and faster settling times in output voltage during such transients. The proposed scheme is tested on a 1-V/12-A buck converter switching at 1 MHz, and the experimental results are presented.      

Interleaved ZVS Converter With Ripple-Current Cancellation

In this paper, an interleaved soft-switching converter with ripple-current cancellation is presented to achieve zero- voltage-switching (ZVS) turn-on and load current sharing. In order to achieve ZVS turn-on, an active snubber is connected in parallel with the primary winding of the transformer. The energy stored in the transformer leakage inductance and magnetizing inductance can be recovered so that the peak voltage stress of switching devices is limited. The resonance at the transition interval is used to realize ZVS turn-on of all switches. In order to achieve three-level pulsewidth-modulation (PWM) scheme, an addition fast-recovery diode is used in the converter. Three-level PWM scheme can reduce the ac ripple current on the output inductor such that the output inductor can be reduced. The current-doubler rectifier is adopted in the secondary side of the transformer to reduce the transformer secondary-winding current and output voltage ripple by canceling the current ripple of two output inductors. The output voltage is controlled at the desired value using the interleaved PWM scheme. These features make the proposed converter suitable for the dc-dc converter with high output current. The operation principles, steady state analysis, and design equations of the proposed converter are provided in detail. Finally, experiments based on a 600-W (12 V/50 A) prototype are provided to verify the effectiveness and feasibility of the proposed converter.     

CCM模式Boost开关变换器的非线性建模和仿真

在开关元件平均模型法的思想基础上,提出了一种工作在连续电感电流模式下的DC-DCBoost(升压)变换器模型。考虑开关电阻、电感电阻及纹波寄生参数的影响,推导出理想与非理想传递函数。对其开环传递函数进行仿真和比较后可以发现考虑电感纹波的模型与实际更加接近,精度更高。     

A new family of isolated converters that uses the magnetizinginductance of the transformer to achieve zero-voltage switching

A new family of isolated, zero voltage switched power converters which utilizes the magnetizing inductance of the transformer to achieve zero voltage turn-on of the primary switches is proposed. By employing saturable inductor(s) on the secondary side, soft turn-off of the output rectifier(s) is obtained with a minimum circulating energy flowing through the power converter. The proposed converters can operate either with a variable or a constant switching frequency. A complete DC analysis and design guidelines for the half-bridge topology are described, and the performance of a 100 W experimental power converter is presented     

A voltage-balanced phase-shifted three-level DC/DC converter operating from high-input voltage

A voltage-balanced phase-shifted three-level DC/DC converter is proposed. Its switch voltage stress is ensured to be only one-half of the input voltage and its four-step operation can reduce considerably the output inductor current ripple. Moreover, it features a small filter, no voltage unbalance problem, static/dynamic sharing of the switch voltage, high-efficiency, and high-power density. It is very suitable for high power converters operating from a high-input voltage.     

Integrated magnetics for current-doubler rectifiers

This paper presents a new integrated magnetic structure for current-doubler rectifiers (CDR). Compared to previously published structures, the proposed design allows the equivalent filtering inductance to be increased with significantly less increase in total winding conduction loss. The increased inductance leads to reduced current and voltage ripple, thereby reducing the size of capacitors required for output filtering. The lower current and flux ripple also helps to reduce the conduction loss and the magnetic core loss. As the result, the overall converter efficiency can be improved, especially under light load when the losses due to ripple current and ripple flux are more significant. Analysis of the proposed structure is presented in the paper, along with an equivalent circuit model suitable for steady-state and dynamic response analyses. Detailed design procedures are also provided by using a half-bridge converter as example. Experimental results from two 100-W, 3.3-V output half-bridge converters are presented to validate the concept and the analyses.     

一种新颖的PFC控制策略

分析设计了一款新颖的功率因数校正(PFC)电路,该电路可以工作于不连续传导模式(DCM)和临界连续传导模式(CRM),并实现两种模式的自动切换,兼具两种工作模式的优势。在输入电压跨零附近,电路工作于固定频率的DCM下,限制最大的开关频率,从而降低污染系统的电磁干扰(EMI)噪声。在输入电压峰值附近,电路工作于频率可变的CRM下,降低升压二极管、功率MOSFET和电感上的电流应力,从而降低费用并且提高电路的可靠性。采用台联电0.6μmBCD工艺仿真验证,得到了近1的功率因数。     

基于UCC28061的交错并联BCM Boost PFC设计

采用UCC28061设计了一款工作在交错并联临界模式下300W的电源。交错并联的Boost PFC拓扑结构,能够大大减小输入电流纹波和输出电容电流纹波。实验结果表明,AC85-265V输入时,功率在300W时PF能够达到0.99以上,电流畸变率THD在3%以下。