PDAC28S14型DC／AC驱动控制电源的研制

本文介绍了已成功地应用于１６０元碲镉汞红外探测系统中的ＰＤＡＣ２８Ｓ１４型ＤＣ／ＡＣ驱动控制电源，详细介绍了这种逆变电源的原理、特点及解决的关键技术问题。     

基于单片机控制的DC／AC变换

本文主要介绍基于单片机控制的DC/AC变换。采用较流行的MCS-51单片机,利用其功能强、速度快、使用灵活的特点,在检测和部分逻辑电路配合下,直接将事先根据能量等效原则存放于EPROM中的SPWM数据按一定规律输出,驱动功率开头管,实现DC/AC变换。本电路采用了较新颖独特的设计,用比较器代替传统的A/D转换,既保证了高速、低成本、又大大简化了电路结构。     

AC／DC电源

这里是最近新推出的一些AC/DC电源     

可满足先进设计需要的高密度AC／DC电源

一个新的超小型高密度AC/DC电源系列满足了低端市场上先进电源方案的需要。这些开关电源的特点是高效率、高电流密度。 这种电源不仅可节省电路板上的空间,使系统添加能实现其它功能的电路,同时可靠性更高(因为不需要散热扇),热性能和EMI性能也更为优化。它们还具有更大的设计灵活性,更好的产品封装形式以及更利于进行生产。 过去,许多公司生产的产品都差不多,设计者没有什么可选择的,只能选低功率AC/DC电源。这些产品又大又重,个均效率不到70％,封装功率密度不到4瓦/立方英寸,电流密度也不大。一个60W电源的尺寸一般是3×5×1.4英寸或者更大一些,而一个100W的电源     

MDAC2475型DC／AC变换器

MDAC2475型DC／AC变换器是输入直流24V,输出交流75V（25Hz)的铃流模块,本文阐述了实现铃流源的几种方法及它们的优缺点,介绍了MDAC2475型DC／AC变换器的电路工作原理及工艺过程,重点介绍了研制过程中解决的几个关键技术问题。     

带Boost型PFC和单开关DC／DC变流器的优越的1000W AC／DC电源能够替代有多开关拓扑的电源

本文分析了一个由Boost型PFC和前向变流器组成的单开关SMPS的电能容量。由于使用了现代无源和有源设备（磁性材料，半导体），这种拓扑的电能应用范围延伸到了通常应用多开关拓扑的领域（大约1kW）。文章对现今关于简单SMPS拓扑的限制进行了理论分析，实际设计，并对一个变流器进行测试。文章最后提出了一些单开关电源拓扑的设计原则。     

基于升降压斩波电路的三相DC/AC逆变器研究

为了解决常用的逆变器所带来的问题,我们提出一种新型的带升降压功能的三相DC/AC变换器拓扑,并介绍了其工作原理。借助于PSIM仿真软件,对单相和三相电路进行了仿真研究,提出了由单相组成三相电压输出的构成方法。在列出仿真参数的前提下,给出了负载电压,负载电流以及调制给定电压和逆变器输出电压的仿真结果。仿真结果表明三相DC/AC逆变器可以实现50 kHz高频功率变换下宽输入电压范围工频逆变输出,证明了理论分析的正确性。     

Benchmark of power packaging for DC/DC and AC/DC converters

This paper presents the first reported final results of a benchmarking project "StatPEP" which investigated the Status of Power Electronic Packaging used in commercial DC/DC and AC/DC switch mode power supplies. The methodology of the project is first described. Some of the salient results of a comprehensive benchmarking of DC/DC converters (rated power of 100 W) and AC/DC converters (rated power up to 576 W) are presented. Examples for figures-of-merit are presented. The results of the investigation are presented in a generic form, which does not identify individual products. A comparison of the performance of the units shows that the measured power density of the AC/DC units is approximately 10% that of the DC/DC while the thermal density based on footprint is 50%. Also the switching frequency of the AC/DC is 50% that of the DC/DC. Some of the reasons for these differences are discussed     

便携式VCD/CD DC-DC变换器原理剖析(下)

为了有一个感性的认识,在VT1导通和截止两种情况下,计算一下变压器②、⑧和⑤端的电压值与哪些参数有关、大小如何?VT1导通:很显然变压器②、⑧电压,V②、⑧=0,而此时初级被激励产生反电动势(即感生电压)等于VDD,所以,因此次级感生电压为- M*VDD(M是次、初级匝比)。VT1截止:重写上面升压变换器输出电压公式:VO=VI*1/(1-D),那么,变压器②、⑧电压,V②、⑧=VDD*1/(1-D),这个值减去电源VDD,即初级感生的附加电压ΔV1=V②、⑧-VDD=VDD*D/(1-D),而次级感生的附加电压ΔV2可由次、初级绕组的匝比M计算得到,于是ΔV2 =M *ΔV1 = …     

A space vector-based rectifier regulator for AC/DC/AC converters

A voltage-sourced rectifier control scheme for use with AC/DC/AC variable speed drives is presented. A control scheme is derived that directly calculates the duration of time spent on the zero state and on each switching state adjacent to the reference vector, over a constant switching interval, in order to drive the line current vector to the reference vector. In addition, under transient conditions, when deadbeat control is not possible, a control scheme is presented that ensures that the line current vector is driven in the direction of the reference current vector. The current reference for the rectifier controller is derived from the bus voltage error and a feedforward term based on the estimated converter output power. The proposed space vector-based rectifier regulator is shown to exhibit improved harmonic and transient performance over existing per-phase duty cycle prediction methods, especially at modulation indices near unity. The deadbeat control of the rectifier input current is accomplished every half-cycle with constant switching frequency while still symmetrically distributing the zero state within the half-cycle period     

便携式VCD/CD DC-DC变换器原理剖析(上)

本文讨论了低压DC/DC变换器,升、降压变换器的模型及实例电路,提出优化参数设计的方法     

AC/DC characterization of NMOS and PMOS hot-carrier-induceddegradation under AC/DC stress

The AC/DC measurements of NMOS and PMOS I_dsat shifts are compared following DC stress. The results of the I _dsat shifts are found to be the same. The AC I_dsat measurements were performed under a variety of different conditions (varying frequency, amplitude, and base level) and showed that hot-carrier-induced interfaced states are shallow and fast (<20 ns). AC versus DC stressing was also examined. In PMOS devices, pulsed drain stress was found to be generally quasi-static, while pulsed gate stress produced enhanced device degradation under certain bias conditions. In NMOS transistors AC drain stress was found to be quasi-static in strong device saturation, while AC gate stress resulted in significantly enhanced degradation. In weak device saturation, both gate and drain pulsing resulted in early catastrophic device failure     

Advanced Integrated Bidirectional AC/DC and DC/DC Converter for Plug-In Hybrid Electric Vehicles

Hybrid electric vehicle (HEV) technology provides an effective solution for achieving higher fuel economy, better performance, and lower emissions, compared with conventional vehicles. Plug-in HEVs (PHEVs) are HEVs with plug-in capabilities and provide a more all-electric range; hence, PHEVs improve fuel economy and reduce emissions even more. PHEVs have a battery pack of high energy density and can run solely on electric power for a given range. The battery pack can be recharged by a neighborhood outlet. In this paper, a novel integrated bidirectional AC/DC charger and DC/DC converter (henceforth, the integrated converter) for PHEVs and hybrid/plug-in-hybrid conversions is proposed. The integrated converter is able to function as an AC/DC battery charger and to transfer electrical energy between the battery pack and the high-voltage bus of the electric traction system. It is shown that the integrated converter has a reduced number of high-current inductors and current transducers and has provided fault-current tolerance in PHEV conversion.     

Control of Single-Phase-to-Three-Phase AC/DC/AC PWM Converters for Induction Motor Drives

This paper proposes a novel control scheme of single-phase-to-three-phase pulsewidth-modulation (PWM) converters for low-power three-phase induction motor drives, where a single-phase half-bridge PWM rectifier and a two-leg inverter are used. With this converter topology, the number of switching devices is reduced to six from ten in the case of full-bridge rectifier and three-leg inverter systems. In addition, the source voltage sensor is eliminated with a state observer, which controls the deviation between the model current and the system current to be zero. A simple scalar voltage modulation method is used for a two-leg inverter, and a new technique to eliminate the effect of the dc-link voltage ripple on the inverter output current is proposed. Although the converter topology itself is of lower cost than the conventional one, it retains the same functions such as sinusoidal input current, unity power factor, dc-link voltage control, bidirectional power flow, and variable-voltage and variable-frequency output voltage. The experimental results for the V/f control of 3-hp induction motor drives controlled by a digital signal processor TMS320C31 chip have verified the effectiveness of the proposed scheme