Dynamic model for AC and DC contactors – Simulation and experimental validation

Electromagnetic contactors have a non-linear behavior due to the magnetic force. This paper develops a robust and low time-consuming parametric model to describe the dynamic behavior of both AC and DC contactors. The proposed model solves simultaneously the mechanic, electric and magnetic coupled differential equations that govern its dynamic response. This model takes into account the fringing flux, an effect that greatly influences the dynamic behavior. In case of AC contactors, the model deals with the shading rings. First, the electric and magnetic equations of an AC contactor – which are more complex due to the effect of the shading rings – are introduced. After that, by simplifying this set of equations, the ones of a DC contactor are derived. Conversely, mechanical equations are the same for both, AC and DC powered contactors. Data from simulations carried out by applying the presented parametric model are compared with experimental data, being demonstrated its accuracy and effectiveness.     

A type-2 fuzzy logic controller design for buck and boost DC–DC converters

Conventional (type-1) fuzzy logic controllers have been commonly used in various power converter applications. Generally, in these controllers, the experience and knowledge of human experts are needed to decide parameters associated with the rule base and membership functions. The rule base and the membership function parameters may often mean different things to different experts. This may cause rule uncertainty problems. Consequently, the performance of the controlled system, which is controlled with type-1 fuzzy logic controller, is undesirably affected. In this study, a type-2 fuzzy logic controller is proposed for the control of buck and boost DC–DC converters. To examine and analysis the effects of the proposed controller on the system performance, both converters are also controlled using the PI controller and conventional fuzzy logic controller. The settling time, the overshoot, the steady state error and the transient response of the converters under the load and input voltage changes are used as the performance criteria for the evaluation of the controller performance. Simulation results show that buck and boost converters controlled by type-2 fuzzy logic controller have better performance than the buck and boost converters controlled by type-1 fuzzy logic controller and PI controller.     

低功耗DC/DC变换器

新型便携式电子产品的特点之一是轻巧。为此,可采用1～2节5~#电池通过高效率的DC/DC变换器产生 5V、 12V等稳定电压,以满足电子线路的需要。这里介绍一组美国LTC公司的低功耗、高效率的DC/DC变换器集成电路。其特点是:组成的稳压电源静态电流小、外围元件少(仅3～4个)、体积小(全部采用贴片式元件)、重量轻,效率高(80％左右)。     

Dynamic evolution control for synchronous buck DC–DC converter: Theory,model and simulation

This paper proposes a new control technique for synchronous buck DC–DC converter. Theory, design and implementation of the proposed control technique are provided. A new approach for converter controller synthesis based on dynamic evolution control theory is presented. In order to synthesize the converter controller, this method uses a simple analysis of nonlinear equation models of the converter. The synthesis process is simple and requires a quite low bandwidth for the controller. Therefore, this control method is suitable for digital control implementation. As an illustrative example, the synthesis of synchronous buck DC–DC converter controller is discussed in detail. The model of the synchronous buck DC–DC converter system was implemented using SimPowerSystems toolbox of MATLAB-SIMULINK. Performance of the proposed dynamic evolution control under step load change and step input voltage condition was investigated. Simulation results confirm that the proposed control method is superior to traditional PI based controller because of fast transient response and good disturbance rejection.     

DC

阳春三月，细雨绵绵，冷却了火爆的年前DC市场，但是也活跃离一部分即将崭露头角的新芽。纵观市场，几大品牌中要数尼康的销售情况最好，这主要是尼康的机器价位合理，外形时尚，功能全面，品质优良。比如尼康5200，这款机器500万像素，才两多块，而且外观十分小巧，性价比很高。     

Analysis and design of single-phase power factor corrector with genetic algorithm and adaptive neuro-fuzzy-based sliding mode controller using DC–DC SEPIC

This paper proposes a methodology for single-phase power factor correction with DC–DC single-ended primary inductance converter (SEPIC) using cascade control strategy which comprises of genetic algorithm-based outer PI controller and an inner current controller which uses an adaptive neuro-fuzzy inference system-based sliding mode controller. DC–DC SEPIC is a fourth-order converter, and in order to reduce the complexity in controller design, reduced-order model of the original higher-order system is obtained by using Type-I Hankel matrix method. The performance of the proposed system is analysed using MATLAB/Simulink-based simulation studies. In order to ensure the robustness of the proposed controller, the performance parameters such as percentage total harmonic distortion, power factor, % voltage regulation, and % efficiency are analysed. From the simulation results, it is inferred that the proposed method provides efficient tracking of output voltage and effective source current shaping for load, line, and set point variations.

     

合理选择DC—DC转换器

讨论线性稳压器、开关型DC－DC转换器、电荷泵等三种DC－DC转换器的特点、如何选用以及应用中的相关问题。     

DC260 DC220双龙出水

记者汪若菡报道柯达公司在'98中国国际照相机械摄影器材与技术博览会上向中国市场正式推出了柯达DC220和DC260数码照相机,其中DC220提供了百万像素(1152×864)和2倍光学加2倍数码的变焦镜头;DC260则具有超百万像素(1536 × 1024)和3倍光学加2倍数码变焦镜头。这两款相机的价格都在万元以下。另外,柯达还附送PICTURE EASY 3.02软件,它可以在WINDOWS 95和NT4.0上运行,能够使用户直接从数码相机、扫描仪、光盘或软、硬盘上获取图像,并对图像进行编辑。     

亿维发布UN CPU224 DC／DC／DC

2011年12月．亿维（UniMAT）正式发布了UN CPU224DC／DC／DC．订货号为UN214-1AD23—0XB0。这是一款由亿维研发部根据多年PLC模块的市场经验．历时1年研发出来的200系列自主品牌PLC控制器模块．在兼容西门子PLC功能的前提下,做了部分优化及功能增强。     

Design methodology and fabrication process of a microinductor for the next generation of DC–DC power converters

Magnetic materials used in cored microinductors to supersede ferrite in the 0.5-10 MHz frequency range are investigated in this article. The performance of electrodeposited nickel–iron, cobalt–iron–copper alloys and the commercial alloy Vitrovac 6025 have been assessed through their inclusion within a custom-made solenoid microinductor. Although the present inductor achieves 77% power efficiency at 500 KHz for 24.7 W/cm3 power density, an optimized process predicts a power efficiency of 97% for 30.83 W/cm3 power density. The main issues regarding microinductor design and performance are discussed.     

DC—DC变换器的SPICE仿真

本文讨论应用ＳＰＩＣＥ通用集成电路计算机分析程序仿真ＤＣ－ＤＣ变换器的方法。着重论述脉冲变压器的回旋器组等效模型、脉宽调制器的等效模型以及双稳态触发器和常用逻辑电路的数学模型。恰当运用上述模型，可仿真所有类型的ＤＣ－ＤＣ变换器，包括谐振变换器、ＰＷＭ变换器、软开关变换器以及开关电容变换器。文中给出了一些实例。     

DC老祖宗

1995年3月10日,是数码相机发展史的大日子。第一部消费级数码相机QV-10便是在那天上市。当年QV-10的售价高达65,000日元,没记错的话,95年100日圆兑1美元左右,大概约人民币6400左右,不计通货膨胀,今时今日足够买到一部入门级DSLR。     

DC新闻

1SONY2GB高速记忆短棒现身PMA在PMA2005上,SONY发布了容量分别为2GB和1GB的Memory Stick Produo,其中2G日的版本是被设计用在支持传输速度最大80Mbps的设备上,工作温度-13°Ft0+185°F。     

DC行情

三星推出的新款卡片相机i6采用600万像素CCD，3倍光学变焦镜头，2．5寸液晶屏幕，1厘米微距。主体黑色卡片机身设计，金属防滑条采用了央扣型设计，使得整机在方正之亦充满流线感，轻薄而时尚。i6不仅能播放MP3音乐，还内建了影片播放程序，可以说该款相机整合了传统DC和MP4的功能。     

DC篇

卡西欧Z60 最便宜的卡片机 要价1900元;松下FZ7 12倍长焦机3450元;理光GR-D 复古感觉 4850元;奥林巴斯SP-500UZ 10倍长焦2850元;索尼W100家用旗舰3050元;佳能A700价格接近2000元。[编者按]     

低功耗电荷泵 DC/DC 升压电路设计

电源管理芯片的应用范围十分广泛,发展电源管理芯片对于提高整机性能具有重要意义,对电源管理芯片的选 择与系统的需求直接相关。其中电荷泵电路通过电荷转移方式工作,来达到在无电感元件情况实现一定升压,因此该升 压电路和该款电源管理芯片在应用中很受欢迎。该设计分析的低功耗电荷泵 DC/DC 升压电路是同国外某公司的合作项 目。该电路采用 0.35 μm 标准的 CMOS 工艺制成,输入电压在 2.5 V～5.0 V,且输入电压高于或低于输出电压时,输出 电压都可保持稳定的低纹波输出,并能自动工作于升压或降压模式。该电荷泵电路采用比较升压电路,有效的降低了芯 片功耗,特别在轻负载情况下提高了系统的转换效率。电路还具有软启动、过热保护及过流保护等多重保护功能。仿真 结果均达到预定指标,是设计理论与实践相结合的一次有价值的尝试。     

DC行情

在1月市场行情上，佳能与索尼的大幅降价引来了极大的连锁反映，尤其在卡片机领域，由于索尼T系列旧款机型价格的下降，其他厂家也都只好跟打价格战的牌，市场上几乎所有的卡片机都有不同程度的降价。而索尼DSC-T9在全国正式上市和卡西欧Exilim Card EX-S600的抢先登陆更在卡片机市场掀起了一阵小旋风。     

DC篇

尼康黄金版S6套装优惠价;奥林巴斯三防相机μ-720SW新低;佳能IXUS800IS促销狂送一堆;索尼T30即将被取代售价小降一百。     

DC篇

中焦新标志佳能G7上市虽然现在中焦DC不太火暴,但佳能没有放松对中焦的掌握,前段时间松下和索尼在12倍光学变焦DC领域的激烈格斗使佳能的影响力削弱了不少,S3 IS一直都不是很受人关注,销量也很一般。G7的到来,是佳能试图翻盘的标志,