中置式高压电容器柜改进设计

分析了南屯煤矿白马河风井变电所高压电容器柜原设计方案存在的问题,并对其进行了改进设计:选用适用于容性负载的真空断路器;添加放电线圈,并将放电线圈与电容器直接并联,使放电线圈与电容器组成一个完整的放电回路;添加接地开关,接地开关既有机械闭锁又有电气联锁,操作方便,安全性高。实际应用表明,改进设计后的高压电容器柜功能更加完善,更加安全、可靠。     

一种低功耗高速的跟随器设计和实现

提出了一种应用于CSTN-LCD系统中低功耗、高转换速率的跟随器的实现方案.基于GSMC±9V的0.18μm CMOS高压工艺SPICE模型的仿真结果表明,在典型的转角下,打开2个辅助模块时,静态功耗约为35μA;关掉辅助模块时,主放大器的静态功耗为24μA.有外接1μF的大电容时,屏幕上的充放电时间为10μs;没有外接1μF的大电容时,屏幕上的充放电时间为13μs.验证表明,该跟随器能满足CSTN-LCD系统低功耗、高转换速率性能要求.     

高熵碳化物陶瓷第一性原理计算研究进展与展望

过渡族难熔金属元素和碳组成的高熵碳化物陶瓷因具有优异的耐高温性能,在高熵材料领域引起了关注。由于涉及复杂的成分范围和服役环境,利用传统试错法研发高熵碳化物陶瓷周期长且成本高,而采用第一性原理计算方法可以准确高效地预测高熵碳化物陶瓷的相稳定性、弹性性能、电子结构和热力学等性质。本文对第一性原理计算方法进行了简述,并对第一性原理计算在高熵碳化物陶瓷研究中的应用成果进行了综述,最后展望了第一性原理计算在高熵碳化物陶瓷领域的发展方向。     

桥丝电点火器的驱动电路设计

用于飞行器姿态控制的脉喷发动机常采用火药包裹的桥丝电点火器进行点火,电点火器需要短时脉冲电流驱动。本文针对微小型桥丝电点火器驱动需求,设计了光耦隔离恒流源方式及电容储能脉冲放电驱动电路,均实现了对阻值波动桥丝电点火器的点火驱动。试验证明,光耦隔离恒流源方式可靠性高,安全稳定,电容储能放电方式效率高、作用迅速。该两种设计方法可为脉喷发动机的工程实践提供参考。     

聚合物纳米电介质材料研究进展及其在埋入式无源元件中的应用概述

聚合物纳米电介质材料由于其出色的机械加工特性、电可调制特性已成为当今高密度封装技术等诸多学科的前沿领域。通过在聚合基体中引入高介电陶瓷或纳米导电颗粒形成具有高介电常数的复合材料,并通过印刷电路板(Printed Circuit Board,PCB)制备工艺内置于PCB基板内部形成埋入式元件(电容、电感及其他无源元件),这已经在电子系统小型化方面显示出巨大的应用前景。文章综述了高介电纳米聚合物复合材料领域近年来的研究进展,探讨了聚合物纳米复合材料在埋入式电容器、电感器中的应用及埋入式无源滤波器的设计方法、制备工艺以及复合材料的电磁特性对埋入式元件电学性能的影响。     

一种非接触高精度平面高度差检测方法

精密光学系统的安装精度要求非常高,必须经过严格检测.提出了一种基于电容传感器的非接触平面高度差检测方法.以精密电容传感器为核心,利用多传感器的相对测量,减小了漂移的影响,实现了高精度测量;通过使用标准厚度块,增大了测量的量程和使用范围.文中对测量的原理和精度进行了分析,经鉴定,该方法测量精度达到2 μm.     

基于MATLAB的高压电容器直流局部放电检测

高压储能电容器在出厂试验中需要有效的检验手段,在使用和存贮中绝缘状况老化的判断也需要有效的检测方法,直流局部放电检测是解决上述问题的有效手段。通过检测高压电容器的直流局部放电信号,分析其信号参量可以对其状况进行有效的评估。该检测基于Matlab软件,通过调用ActiveDSO,用PC机控制示波器,在MATLAB环境中获取示波器采集的数据并进行数据分析。试验结果表明不同状况的高压电容器的局部放电信号参量具有明显不同。     

宽带高效超声波传感器的研究

提出了一种新型的双层压电结构超声波传感器 ,借助于移相电容器的移相作用 ,改变各压电层的激励电压的幅值和相位 ,实现对传感器频率特性的控制 ,从而得到了具有宽频带高效率的超声波传感器 ,为研究宽带高效超声波传感器探索了一条新的途径     

光伏阵列伏安特性测试系统设计

基于对光伏电站控制和设计水平的要求,本文提出一种基于电容充放电的特性的光伏阵列伏安特性测试系统。本文阐述了测试系统的工作原理和系统关键的部分。当光伏阵列给电容充电时,得到当时环境中光伏阵列的电压、电流以及相应的功率特性曲线。同时对M*N的光伏组件进行建模,得出组件的相应的电性能参数,并对最大功率点进行分析。最后进行实验验证。本测试系统具有测量精度高、系统稳定性高、成本低廉,并且能更直观的测得光伏阵列的特性。     

一种汽车动力电池模拟负载电路设计方案

为解决BMS系统中涉及电池平衡相关功能的软硬件开发、测试、生产等对电池负载的需求,介绍了一套电路设计方案,来模拟真实的电池电特性。此系统包括电池单体模拟电路、电容充放电电路、电容电压监控电路、Pack模拟电路等电路模块。同时,负载电路还有拼接功能,满足不同规模大小的测试需求,其控制接口采用CAN总线,具备控制简单,便于集成的特点。模拟负载拥有真实负载所不具备的诸多优点,如一致性好,可重复性高,状态改变快,使用寿命长,模拟工况丰富等,因此它是BMS开发工程师的必备工具,对推动BMS系统研发有积极的意义。     

矿用级联型高压变频器母线电容控制策略

针对H桥逆变器级联型高压变频器母线电容体积大的问题,提出了一种在基波调制信号中注入三次谐波以减小母线电容容量的控制策略。在总调制比不变的情况下,三次谐波注入等价于将母线电容电流的低次谐波部分转化为高次谐波,从而减小了母线电压纹波。推导了母线电容电流谐波含量与三次谐波注入量的关系,并给出了不同功率因数下三次谐波最大注入量的表达式。Matlab/Simulink仿真结果表明,在功率因数为0.85的典型负载下,采用本文控制策略可将母线电容容量降低24.2%,验证了该控制策略的可行性和有效性。     

抗闩锁效应微处理器复位电路设计研究

主要探究解决控制系统在频繁通断电情况下容易死机的问题。通过对传统微处理器复位电路的理论分析和工作波形仿真,发现在电源掉电时,微处理器在其复位引脚受到外部复位电容的放电冲击时,容易进入闩锁状态。由此提出上电复位电路也是容易导致CMOS电路进入闩锁的外部触发条件之一,并在此基础上设计了一种新型抗闩锁复位电路,能够自动检测电源掉电,导通泄流回路,使复位电容避开复位引脚放电。仿真分析和样机测试验证了其抗闩锁功能的有效性。     

基于电磁储能的电网新能源消纳能力仿真分析

为合理调节电磁储能,在实现电网运动运行基础上加强新能源电能利用率,提出基于电磁储能的电网新能源消纳能力仿真分析方法.为准确地反映出电容器在工作过程中不同时间段内特征动态变化过程,采用改进后三支路模型对超级电容储能系统精确建模,根据超级电容恒流放电曲线完成三支路模型中等效电容值、串联电阻值和并联电阻值的辨识.对超级电容电...     

High‐speed low‐voltage driving of high‐Xe‐content PDPs with priming particles

Abstract— Power savings, image‐quality improvement, and cost reduction are the major issues facing PDP development. High‐Xe‐content PDPs have attained improved luminous efficiency, but with sacrifices in higher switching and sustain voltages and slower discharge build‐up. By examining PDPs having 3.5%–30% Xe content, it was found that utilization of the space‐charge priming effect as well as wall‐charge accumulation are effective in obtaining a low operating voltage and a high switching speed. The improvements are enhanced for higher Xe pressures. By using space‐charge priming, the statistical time lag of the discharge triggering for the 30% Xe content is reduced significantly and becomes approximately equal to that of 3.5% Xe content. Once triggered, the formative time lag of the discharge becomes shorter and the space charge experiences diffusion/drift; hence, accumulation of the wall charge is faster for discharges with higher Xe contents. These indicate that the use of an erase addressing scheme, rather than a write addressing scheme, is preferable when driving high Xe‐content PDPs, because the erase addressing scheme provides the addressing operation with an abundant amount of priming particles. Also, the drive voltages are lower for the erase addressing scheme. In order to reduce the address voltage, it is effective to accumulate wall charges prior to addressing. It was found that there are limiting values for the charge accumulation, above which self‐erase discharges ignite and the wall charge is dissipated. The self‐erase discharge occurs at relatively low wall voltages when the Xe percentages becomes higher. The sustain pulse voltage can be reduced while keeping the luminous efficiency high by increasing the sustain pulse frequency. As the frequency is increased, a residual amount of space charge created by the preceding sustain pulse increases. Due to the priming effect of these space charge, the build‐up of the discharge current becomes faster, resulting in a lower voltage.     

Pixel structures using the negative feedback method for high‐resolution active matrix organic light‐emitting diode displays

Novel two pixel structures are proposed for high‐resolution active matrix organic light‐emitting diode displays. The proposed two pixels (pixel structures A and B) use the negative feedback method for high‐resolution displays that requires to have small‐sized storage capacitance. The proposed pixel structures A and B improve the luminance uniformity by reducing the voltage distortion in the storage capacitor. However, the proposed pixel structure A is vulnerable to the organic light‐emitting diode (OLED) degradation because the anode voltage of the OLED affects the emission current. In order to compensate the OLED degradation, the proposed pixel structure B stores the turn‐on voltage of OLEDs in the storage capacitor. The simulation results show that the emission current error of the proposed pixel structure B is improved by four times in comparison with the proposed pixel structure A when the OLED turn‐on voltage increases by 0.1 V. Also, the emission current error of the proposed pixel structure B when the threshold voltage of driving thin‐film transistors varies from ?2.2 to ?1.8 V is from ?0.69 least significant bit (LSB) to 0.13 LSB, which shows the excellent luminance uniformity. The proposed pixels are designed for 5.5‐in. full high‐definition displays.     

Discharge diagnosis of high Xe concentration and high‐γ protective layer in PDPs

Abstract— The high‐Xe‐concentration and high‐γ (ion‐induced secondary‐electron emission coefficient) protective layer have been diagnosed from both experimentation and simulation. The experimental results show that there is a great increase in luminance and luminous efficacy, while the breakdown voltage decreases in the high‐Xe and high‐γ discharge. In the high‐Xe discharge, the great increase in VUV radiation mainly results from an increase in excimer VUV emission. The application of high‐Xe concentration can greatly increase the luminous efficacy, while the high‐γ protective layer can promote it further. Considering that the total discharge efficiency can be divided into the electron heating efficiency, the Xe excitation efficiency, and the VUV radiation efficiency, both the electron heating efficiency and Xe excitation efficiency increased for a high‐Xe discharge; while for a high‐γ discharge, the increase in electron heating efficiency contributes to the improvement in discharge efficiency.     

超级电容的充放电控制策略研究

超级电容作为一种绿色环保、高效实用的新型储能装置,具有充电时间短、使用寿命长、温度特性好、节约能源和绿色环保等特点。因此在众多领域有着巨大的应用价值和潜力。针对超级电容模组的额定电压为15V,功率为500W的实验平台,研究了电流电压双闭环控制特点,比较了恒压充电和先恒流再恒压充电的效果,在电流电压双闭环控制作用下,超级电容模组在放点是能够很好地跟踪功率的变化。达到了预期的实验目标。     

A 550‐PPI LCD using 1.5 µm channel width LTPS TFTs with low frame rate driving

A 550 PPI low‐temperature polycrystalline silicon thin‐film transistor liquid‐crystal display has been developed. Shrinkage of the channel width of pixel thin‐film transistor together with thinner insulator for the storage capacitor allows high display quality in terms of vertical cross‐talk and flicker. Thirty hertz frame rate driving is implemented to offer low power while keeping high display quality.     

磁阻驱动器电路参数对发射性能的影响

介绍了磁阻驱动器的理论模型和计算方法,着重仿真了在给定的磁阻驱动器结构下放电电容参数对出口速度的影响。利用电解电容器作为脉冲电源,采用可控硅开关,设计并组建了磁阻驱动器,利用铁磁质弹丸进行了试验,验证了电容器的电压、容值参数对出口速度的影响规律。     

在微细电火花加工极间放电状态高速采集系统中的DMA技术

为了提高微细电火花加工的脉冲利用率,控制系统要求能对一段时间内的放电状态进行连续采集。通过对待测信号的调理,使采集系统的任务降到只需以微细电火花脉冲电源速率进行采样即可,即速率要求为２ＭＨｚ。然而市场上的板极采集元件不是达不到速度要求,就是速度太高,功能冗余,价格昂贵。为此,笔者采用了ＤＭＡ技术,配合高速Ａ／Ｄ转换器ＡＤＣ－２０８ＭＣ的应用,设计了一个适用于极间放电状态检测的高速采集系统。文中对该