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.     

槽孔式水力驱动控制棒槽孔阻力系数实验研究

对槽孔式水力驱动控制棒槽对孔阻力系数进行了大量实验研究，获得了槽孔式水力驱动控制棒槽对孔阻力系数和其随槽对孔位移的变化规律，分析了槽对孔阻力系数与控制棒槽对孔结构参数之间的关系。结果表明：随槽对孔位移的增加，槽对孔阻力系数从某一较大的定值迅速降低到某一较小的定值，然后再迅速反回到初始的定值，形成一个对称的宽幅波谷；槽高使阻力系数曲线波谷幅宽发生变化，也使完全不重合段的阻力系数发生变化；随内套孔径的增大，阻力系数有所降低，其对阻力系数的影响也进一步减弱。孔径增大到一定程度，阻力系数基本不受孔径参数的影响。     

基于Winsock 的多线程CAMAC通信服务器软件的设计与实现

叙述了应用 Winsock技术与多线程技术实现高性能的 CAMAC通信服务器程序。介绍了整个程序的设计实现方法 ,重点介绍了网络通信服务的实现和多线程访问设备时的同步问题     

起重机吊钩拖动绕线电动机他励双高调速系统

本文提出励磁电流可自动控制的他励式双高调速系统设计方案。系统在提升特别是在下放重物时，具有较硬的机械性；在负载１０－１００％的变化范围内，可实现最大偏差Δｎｍａｘ／ｎｍｉｎ１００％≤１０％，调速范围Ｄ≥１０；在满载运行条件下，可节约电能８０％以上。     

智能控制在回转窑配料系统中的应用

本文介绍智能控制在回转窑配料系统中的应用情况，并阐述该控制器设计、构成、软件系统特点及现场运行效果。     

一种新的机器人手臂控制方法

从机器人手臂的关节电机力学出发，本文提出了一种独立于现行机器人关节控制器的离线补偿方法，通过对－２自由度机器人的数值研究，证明该法不仅能有效地克服由于惯性负载，关节间耦合与重力效应给控制系统带来的动态精度问题，而且还可以消除由于控制系统本身的固有特性所决定的系统的跟踪误差。     

Passive least-squares-type estimation algorithm for direct adaptive control

The standard least squares (LS) estimation algorithm is modified in such a way that it becomes passive. Therefore the scope of application of the LS algorithm is extended to those adaptive schemes whose convergence proof is based on passivity. The passive version of LS is presented in both continuous and discrete time.     

对洪水分级的浅见

洪水的等级划分应考虑流量、水位、防洪能力及灾害等因素,综合这些因素把洪水分成5个等级。1、2级洪水,洪水流量小,水位低,基本无灾;3级洪水,洪水流量较大或水位较高,有一定灾害;4级洪水,为大洪水或高水位,有较大灾害;5级洪水,为特大洪水或高水位,灾情严重。