Fabrication of a poly-Si thin-film transistor with storage capacitor

The fabrication process of a low-temperature poly-Si thin-film transistor (TFT) with a storage capacitor was studied. The atmospheric-pressure chemical-vapour deposited SiO₂ protected the buried indium tin oxide (ITO) from reduction by a pure H₂ plasma treatment that was essential for the effective improvement of the poly-Si TFT characteristics. Thus, a storage capacitor with an ITO (picture electrode)-SiO₂-ITO (buried common electrode) structure was successfully fabricated. The poly-Si TFT with a channel width/length W/L ratio of 5 drove a 3 pF storage capacitor in 2 μs, and it showed superior driverability for LCD use. The TFT also had good hold characteristics under illumination for the realization of grey-scale representation.     

Stabilization of inter-area and/or oscillatory modes in large-scale power system by voltage impedance power system (VIPS) apparatus based on decentralized control scheme

New technologies such as power electronics have made it possible to change continuously the impedance of a power system not only to control power flow but also to enhance stability. A power system incorporating a variable impedance apparatus such as a variable series capacitor (VSrC) and high-speed phase shifter (HSPS) is called VIPS (Variable Impedance Power System) by the authors. This paper proposes a novel control method of VIPS apparatus such as VSrC and HSPS installed at an interconnecting point for stabilizing inter-area unstable and/or oscillatory modes. The proposed design method of the control system is a kind of hierarchical decentralized control method of a large-scale power system based on a Lyapunov function. Under the proposed control scheme, each subsystem can be stabilized independently by local controllers such as AVR, speed governor and PSS, and then the whole interconnected system can be stabilized by VIPS apparatus taking into account interactions between subsystems. The effectiveness and robustness of the VIPS apparatus control are shown by numerical examples with model systems including a large-scale power system.     

片式阻容元件的现状和发展方向

在国外的片式元器件（ＳＭＤ）中，片式阻容元件发展最快，主要表现为片式化率迅速上升，尺寸越来越小，性能越来越好，包装形式多样化和生产管理不断改进。本文综述了国外阻容元件在这些方面的进展，指出了我国的差距，提出了我国如何发展的措施。     

铝电解电容器用橡皮塞中铁的测定

主要研究了用硫氰酸钾作显色剂，用分光光度法测定橡皮塞中铁含量的方法。并对国产和进口橡皮塞做了比较，为铝电解电容器质量水平的提高提供一条新思路。     

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。     

电感电容损耗电阻的讨论

通过对电容电感阻抗的测量，发现实验值偏离理论值。定性地分析了误差的来源，得出的结论是电感电容内部的损耗电阻随着频率的变化而变化，变化方向相反而并非相同。     

电压波动和闪变对整流桥后电解电容器的影响

电网电压存在波动和闪变,使整流桥后电解电容器的纹波电流明显增加,导致其损耗增加和使用寿命缩短。为了分析该现象的成因和机制,利用三角函数模型定性分析电网电压波动和闪变引起电解电容器纹波电流的变化情况,同时推导验证了其有效值变大的现象。同时还介绍了电容器纹波电流的测试方法,并采用具有傅里叶分析功能的示波器对实际样机的纹波电流进行测试分析,获得了支持理论分析的实验数据和结果。     

基于粒子群算法的轨道电路补偿电容故障诊断方法

为了延长轨道电路传输距离,改善传输效果。本文提出一种机车信号感应电压幅值包络仿真模型,它是基于均匀传输线理论,通过补偿电容对机车信号感应电压幅值包络的影响规律,使用改进粒子群算法得到当前状态下补偿电容的最优值,进而对补偿电容的故障进行诊断。仿真结果表明,这种诊断方法是可行和有效的,能快速准确地定位故障补偿电容,替补偿电容的故障诊断提供了新的有效手段。     

基于超级电容的电梯能量再生系统

针对电梯采用制动电阻消耗回馈能量造成的极大浪费,介绍基于超级电容的电梯能量再生系统及其控制逻辑的设计。     

Performance of positive and negative electrodes in amorphous manganese oxide supercapacitor

Using potassium permanganate and acetic manganese as the reactants, amorphous manganese oxide was prepared with mechanochemical method. XRD was used for microstructure characterization, while cyclic voltammetry and constant current charge-discharge were used for electrochemical performance testing. The positive electrode （PE） and negative electrode （NE） were investigated respectively in amorphous manganese oxide supercapacitor, aiming to find their different performances in charging-discharging. The results show that the crystalline structure is destroyed in both the PE and NE material during charge-discharge process. Thereinto, the NE suffers a bit more seriously. When cycling, the PE potential scope diminishes while the NE potential scope enlarges. The increased inner resistance makes the NE curves almost bended to be a right angle, but not the PE curves. The cell＇s equivalent series resistance （ESR） is more dependent on the NE, and the capacitance is mainly determined by the rapid descent of the NE potential range. The capacitances of the NE are highly rate-dependent, decreasing from 121.3 to 53.1 F/g, by 56.2%, over the range of 5-25 mV/s. However, the PE appears to be weakly dependent and its capacitance is only dropped by 22.1%.