直流双闭环调速系统的设计与仿真

采用MATLAB软件中的控制工具箱对直流电动机双闭环调速系统进行计算机辅助设计,并用SIMULINK进行动态数字仿真,结果表明,用MATLAB软件是控制系统设计与仿真的一种功能完善、编程简单、且具有较高精度的有力工具.     

带电压内环的直流调速系统的设计与仿真

带电压内环的直流调速系统与转速、电流双闭环直流调速系统相比,在电流环内多加入一个电压环,能及时调节电网电压波动所造成的的扰动.以小功率直流电机为对象,采用工程设计法,对电压调节器、电流调节器和转速调节器进行设计,并在Matlab的Simulink环境中对系统进行仿真与调试,最后得出满足系统相应性能指标的一组参数.     

对直流高压试验中电压极性的研究

为了能够准确及时的发现直流高压设备中潜在隐患问题,有必要对直流高压进行试验,并对此问题进行深入分析研究。本文选择对直流高压实验中电压极性的研究作为课题进行此方面的问题研究与探讨。     

高压直流输电系统损耗浅析

一个高压直流系统的换流站的损耗可以分为晶闸管阿损耗、换流变压器损耗等八大部分,各部分分别计算,再求和即可以得到整个换流站的损耗.各部分顿耗大小和运行参数值相关,而各个运行工况下的运行参教、设备投入情况又不同.     

高压直流输电系统阀短路保护动作研究

阀短路所形成的保护动作对高压直流输电系统的换流器起到一定的保护作用,对高压直流输电系统的安全运行有着重要的意义.本文通过分析系统阀短路保护的保护测点及范围,并利用实时数字仿真技术来做实验证明高压直流输电系统阀短路保护动作运行理论的正确性,以保证高压直流输电系统的正常运行.     

基于SIMULINK的转速单闭环直流调速系统的仿真

为了提高直流调速系统的动静态性能指标,通常采用闭环控制系统（包括单闭环系统和多闭环系统）。对调速指标要求不高的场合,采用单闭环系统,而对调速指标较高的则采用多闭环系统。按反馈的方式不同可分为转速反馈,电流反馈,电压反馈等。在单闭环系统中,转速单闭环使用较多。     

基于单片机的模糊PID控制双闭环直流调速系统研究

本文针对机床加工过程中需要高性能可控电力拖动和经常正反转运行的问题,设计了基于单片机的双闭环直流调速系统,采用模糊PID控制的方法,研究分析了模糊PID参数自整定的性能,通过仿真证明了该系统的有效性。     

基于Matlab的直流电动机起动的仿真分析

结合实际,谈谈基于Matlab的直流电动机起动的仿真分析。     

高压直流换流器差动保护异常动作分析

通过实际工作中的非典型高压直流换流器差动保护异常动作的案例分析,阐述了如何通过故障特征进行故障分析,提出相应措施,具有一定参考指导作用。     

高压直流输电的特点与展望

文章回顾了高压直流输电技术的发展历史,介绍了直流输电系统的基本原理、技术特点和应用现状,并预测了高压直流输电的发展前景。     

Pulse-width-modulated speed control of d.c. motors

This paper deals with the analytical and experimental investigations of an open-loop pulse-width-modulated d.c. motor speed control system. The analysis is carried out by two different approaches, circuit approach and the lattice function approach. From the circuit approach, the relationship between the current-ripple-factor and the pulse width is obtained. The lattice function approach yields the relationship between pulse width and the speed variation. There is good correlation between the experimental and theoretical results.     

高压磁控软起动装置在除尘风机上的应用

本文主要介绍磁控软起动装置的工作原理,起动特性及其在大型高压电动机上的成功运用.     

220kV母差失灵保护二次回路设计及应用

论述了目前电力系统220kV双母接线方式线路、主变保护失灵启动回路的几种方式。依据有关设计规范及反措文件,结合广东电网的实际情况,对220kV母差失灵保护二次回路设计要求及应用进行评价、优化,并提出了220kV母差失灵回路的验收方法及定期校验中应对失灵启动回路采取的安全措施。     

On rectangular systems of differential equations and their application to circuit theory

A system of differential equations A(d/dt) x = Bx+f, along with the initial condition x(0) = k, is considered where A and B are m x n matrices. Generalized inverses of the matrix A are used to derive algebraic conditions for the existence and uniqueness of a solution. An example is presented to illustrate application of the results to circuit theory.     

中国科学院与载人航天工程应用系统

飞船应用系统是我国空间任务中规模最大、涉及领域最广的空间科学与应用研究任务。文章系统地总结了中国科学院在载人航天工程应用系统中所承担的任务、研制过程以及在空间对地观测、空间科学实验和探测方面所取得的成果。     

Robust finite-time stabilizers for five-degree-of-freedom active magnetic bearing system

In this paper, the robust finite-time stabilization problem for a fully suspended five-degree-of-freedom active magnetic bearing system is addressed in the presence of external disturbances and additive uncertainties. By developing the nonsingular terminal sliding mode control and defining new nonlinear sliding surfaces, three separate classes of stabilizers are proposed to regulate and place the suspended rotor in the desired positions of air gaps within adjustable finite times. The suggested nonlinear sliding surfaces and designed control inputs for each class of stabilizers are two major differences between these stabilizers. It is mathematically proven that five control voltages of this system, designed by each class of the suggested stabilizers, are able to locate the suspended rotor at the centers of air gaps in the adjustable finite time which is summation of two reaching and settling finite times. Moreover, several new inequalities are extracted for determining the reaching and settling finite times related to the three classes of stabilizers. These inequalities reveal the dependencies between optional parameters of the proposed stabilizers and the mentioned finite times. Finally, numerical simulations are provided to illustrate the efficiency and good performance of each class of the designed stabilizers.     

CAS leads development of application system for spaceship

The spacecraft Shenzhou-VII blasted off on 25 September, carrying three astronauts to attempt China＇s first-ever spacewalk. It is the seventh space mission successfully launched by this country. As usual, its space application system, one of the seven major systems for this space engineering project, is developed under the leadership of CAS.     

模糊信息融合在电子电路故障诊断中的应用

本文提出了电子电路故障定位的多传感器模糊信息融合方法。通过测试电路中的被诊断元件的工作温度和工作电压两个物理量,得出模糊信息理论中两传感器对各待诊断元件的故障隶属度,再利用模糊信息融合,确定故障元件,并通过单传感器诊断结果与模糊信息融合诊断结果比较,说明多传感器融合的优越性。