高功率脉冲变压器设计

简要介绍了高功率脉冲变压器,讨论了国内外该领域相关研究现状,总结了高功率脉冲变压器设计中减小上升时间及顶降,展宽输出脉宽,提高耐压性能及能量效率的方法和闭路磁芯的应用.为了使高功率脉冲变压器具有高能量传输效率,且输出波形上升时间短,脉冲宽度宽,本文采用具有高磁导率和高饱和磁感应强度值的磁性材料制造的闭路磁芯,并在变压器...     

Design issues and insights for low-voltage high-density SOI DRAM

A physics-based study of floating-body effects on the operation of SOI DRAM is described. The study, which is based on device and circuit simulations using a physical SOI MOSFET model calibrated to an actual partially-depleted (PD) SOI DRAM technology, addresses the performance of the peripheral circuitry, e.g., the sense amplifier, as well as the dynamic retention of the data storage cell. Design insight for low-voltage high-density SOI DRAM is attained. Double cell design is shown to yield a dynamic retention time long enough for gigabit memories, and crude body-source ties for nMOS, with pMOS bodies floating, are shown to effectively suppress instabilities in the sense amplifier     

高效率Doherty放大器的设计与仿真

效率和线性度是功率放大器的两个重要指标,影响着整个系统的性能.通过比较各种提高效率的方法中,选择结构简单的基于Doherty技术的功率放大器来实现.首先介绍了Doherty功率放大器的基本工作原理,然后选用飞思卡尔的MRF6S21140H芯片,应用微波仿真软件ADS设计了频段在2110～2170MHz的高效率Doher...     

Design and analysis of a high efficiency linear power amplifier

A high efficiency linear power amplifier is introduced based on the idea of Switch-Linear Hybrid (SLH) power conversion. The SLH power amplifier developed from the conventional class B power amplifier, while the class B configuration power unit in the SLH power amplifier is fed by a dynamic switching power supply, not the usual constant DC power supply. Thus, the efficiency of the class B configuration power unit in SLH power amplifier can be greatly improved. By combining linear power amplifier with switching power supply, the SLH power amplifier has synthetic performance of high fidelity, high efficiency and excellent dynamic characteristics. In this article, analysis of SLH power amplifier is performed, especially focusing on its linear power unit which is the core of SLH power amplifier. Design considerations are also presented parallel with the analysis. Both the theoretical analysis and experimental results verify the validity of SLH power amplifier.     

高效率音频功率放大器的设计

本文主要介绍的是通过普通电子元件设计出高效率音频功率发大器的方法.它不仅能够减少电路的成本,同时还能够将放大器的效率给提高.该设计中的PWM电路是由基本的运算放大器所构成,从而形成了能满足高效率,低失真要求的D类功率放大器.     

一种高效的低压电力线通信组网算法设计

为了满足低压电力线网络的自适应性、时效性需求,在分析了电力线网络信道特点及拓扑结构后,指出了侦听一个时间片循环以优选最短路径的思路,提出了一套基于时分复用信道接入机制的自适应组网算法,给出了算法网络层协议及对应状态机,并使用Matlab建立了一系列仿真模拟机制及节点模型,以仿真电力线网络上实时数据流信息和组网结果。仿真结果表明,相比近年来的分簇算法,该算法在组网时间、平均通信长度和平均通信跳数方面都有明显优化,能在组网时效性和网络性能方面取得平衡。     

载流子平衡的低压高效有机白光器件

研究了结构为ITO/m-MTDATA:x%4F-TCNQ/NPB/TBADN:EBDP:DCJTB/Bphen:Liq/LiF/Al的有机白光电致发光器件(WOLED)。分别在ITO与NPB间加入高迁移率的m-MTDATA:4F-TCNQ来增强器件的空穴注入,在阴极和发光层间加入高迁移率的Bphen:Liq层增强器件的电子注入,降低驱动电压,提高器件效率。同时,由于注入的电子和空穴数量偏离平衡,器件的效率也会受到影响。实验中,通过调节4F-TCNQ的掺杂浓度来调控空穴的注入和传输,使载流子达到高度平衡。器件的最大电流效率和流明效率分别达到了9.3cd/A和4.6 lm/W。     

低压智能型无功补偿控制器的设计

文中根据DSP-TMS320F2812低功耗,高性能的优点以及计量芯片ATT7022A具有高精度的优点.提出一种利用DSP-TMS320F2812为主控制器和ATT7022A联合的智能型无功补偿控制器.给出了具体实现的方案,电路组成图,补偿方式以及软件流程.该控制器很好的融合了微控制器和高性能数字信号处理的功能,提高了补偿精度并具有LCD液晶菜单显示,自动采样、无功调节、数据存储以及远程数据查询等功能.     

低压电力线载波通信结合滤波器设计

低压电力线作为载波通信信道时,其通信特性并不理想,各种负载、用电设备及外界都将引起大量的噪声,给电力线载波通信带来了严重的干扰问题,从而影响电力线通信系统的性能。为了保证载波通信信号和数据的有效传输,通过电路分析并设计一种低压电力线载波通信结合滤波器,经仿真与实验该滤波器能有效过滤低压电力线载波通信信道中的各种干扰信号,从而达到了保证载波通信信号和数据的有效传输的作用。     

用于无线能量传输的高效率半导体激光器设计

激光无线能量传输在无人机、卫星空间站和探月机器人供电等方面具有潜在应用前景,其系统效率成为了其应用的关键瓶颈。为了提高激光无线能量传输系统发射端激光器的电光转换效率、接收端光斑均匀性和有效窗口收光比,提出了用于激光无线能量传输发射端的高效率半导体激光器设计方案。基于合束效率较高的空间合束设计了一套高功率高效率半导体激光系统,接收端光斑不均匀度可优化至0.207,有效窗口内收光比大于94%。搭建了千瓦级激光无线能量传输实验装置,发射端半导体激光系统直接输出矩形光斑,与矩形光电池匹配,提高了电池阵布片率。利用多光束指向性可调节特点,优化了接收端光斑均匀度,有利于提高接收端电池的转换效率及简化电源管理。该设计与研究为激光无线能量传输的实际应用提供了借鉴意义。     

Design of a high-frequency planar power transformer in multilayertechnology

A high-frequency power transformer using multilayer printed circuit board (ML-PCB) technology is presented for applications in switched-mode power supplies operating at frequencies up to several megahertz. The mechanical configuration of laboratory prototypes is discussed, as well as the electrical, parasitic, and thermal behavior. The focus is on the leakage inductance, since the analysis of other aspects is relatively simple. Test results show that the transformer has high efficiency, low leakage inductance, good thermal behavior, and good line insulation properties. The topology enables the designer to make a trade-off between leakage inductance and interwinding capacitance. Due to the well-defined geometry, parasitic interwinding capacitance and leakage inductance are reproducible and can be computed relatively easily     

Coreless printed circuit board (PCB) transformers with high power density and high efficiency

The authors report the use of a coreless printed circuit board transformer for power conversion with very high power density and efficiency. A coreless PCB transformer with an outermost radius of /spl sim/1 cm and 19 turns for both the primary and secondary windings can transfer 19 W at an efficiency of 90%, resulting in a record power density of 24 W/cm/sup 2/. The power density and energy efficiency of a coreless PCB transformer are higher than those of core-based microtransformers. Coreless transformers are simpler in structure, easier to implement in silicon wafer and cheaper than core-based planar transformers.     

基于LPC2220低压无功补偿控制器设计

本文设计了一种基于ARM7TDMI-S处理器LPC2220为主控制MCU,以复合开关为电容投切开关的压无功补偿控制器.该控制器能够实现自动采样计算、无功自动调节、故障报警保护、数据存储等功能.并具有LCD液晶菜单显示,直观地显示测量基本电网参数.软伟设计采用基于嵌入式实时操作系统μC/OS-Ⅱ.并且可通过上位机进行实时电网参数、电容投切情况、及历史数据的远程查询.     

Practical control for improving power density and efficiency of the BLDC generator

This work presents an advanced control technique for maximizing power density and efficiency of the brushless dc generator by using a linear tracking method and also suggests a sub-optimal control method in practical applications. In a generator of given rating, the weight and size of the system affect the fuel consumption directly; therefore, power density is one of the most important issues in a standalone generator. Conventional rectification methods cannot achieve the maximum power possible because of a nonoptimal current waveform. The optimal control scheme to maximize power density and minimize machine size and weight in a nonsinusoidal power supply system has been derived, incorporated in a control system, and verified by simulation and experimental work. A new simple algebraic method has been proposed to accomplish the proposed control without a fast Fourier transform which is time consuming and complicated.     

开关电源反激变压器选型设计步骤简介

开关电源广泛应用于电气行业,具有效率高、重量轻、稳压范围宽、安全可靠、功耗小等优点.反激拓扑是开关电源中最简单的隔离拓扑结构,具有元件少、成本低、自动复位等显著特点,而且既可以升压也可以降压,具备其它拓扑结构无法替代的优势,而反激变压器则是此拓扑结构中最为关键的器件.     

Design issues of a three-dimensional packaging scheme for power modules

This paper presents design issues of a novel three-dimensional packaging approach for power modules. Solder interconnections are implemented on power devices (insulated gate bipolar transistors and diodes) to obtain vertical interconnections for the proposed multi-layer packaging technique. Issues related to materials selection and processing, electrical and thermo-mechanical aspects of implementing the new packaging concept are discussed.     

Impulse-doped GaAs power FETs for high efficiency operation

The authors have fabricated impulse-doped GaAs power FETs demonstrating 59% power-added efficiency with 10.4 dB associated gain and 0.33 W/mm at 10 GHz. To the best of their knowledge, this is the highest power-added efficiency ever reported at X-band for a GaAs FET     

A composite varactor for simultaneous high power and high efficiency harmonic generation

The proposal of connecting several varactor wafers in series to obtain higher breakdown voltages without loss of cutoff frequency is explored theoretically and experimentally. Calculations indicate that for a common wafer and junction geometry, the cutoff frequency of series-stacked varactors will vary approximately as VB^-1/2instead of the more rapid VB^-1or VB^-3/2variation characteristic of a single wafer. The virtue of this scheme has been demonstrated in a 4-to-12 Gc/s multiplier using varactors consisting of 1, 2, 3, and 4 series-connected, epitaxial GaAs, surface barrier wafers. As anticipated, the varactor breakdown voltages increased directly with the number of wafers employed and the power capability as the square of that number, while efficiency decreased only slightly. A maximum power output of 1.2 watts at 12 Gc/s was obtained with 62 percent efficiency in a tripler circuit.     

低电压电源系统的发展趋势

过去的十年时间里,大多数电子设计人员都逐渐放弃了集中式供电方式。电路板上的砖式DC/DC电源转换器提供了更为灵活的解决方案。现在,这种方法又正在被基于中间总线结构的电源输送系统所代替。     

基于ARM的电力变压器风冷实时调节系统设计

大部分传统电力变压器风冷调节系统主要通过人工方式闭合和断开机械触点调节冷却器投切,自动化程度较低,容易使电力变压器出现电火花,无法保障电力变压器安全运行。因此,设计基于ARM的电力变压器风冷实时调节系统,系统中的信息采集模块将采集的变压器油温信息、负荷开关量信号和温湿度信号等测量参数传输到ARM控制器后,ARM控制器将油温信息传输到冷却器控制电路,在该电路中根据采集油温值高于设定油温值程度判断开启冷却器个数,实现冷却器的运转和停止,达到实时调节电力变压器风冷的目的,实现无触点化控制。经过实验分析发现,经过该系统调节的电力变压器平均温差和灵敏度分别为12.08℃和99.9%,说明该系统能实时调节风冷,降温效果较好。