文档介绍：摘要
本毕业论文所研究的是双闭环三相异步电动机的串级调速的基本原理与实现方法。对于绕线式异步电动机来说,由于改变其转子绕组控制变量以实现调速,转子侧的控制变量有电流、电动势、电阻等。通常转子电流随负载的大小决定,不能任意调节;而转子回路阻抗的调节属于耗能型调速,缺点较多,所以转子侧的控制变量只能是电动势,这也是本文所要研究的重点之一。
利用串级调速系统,就是使绕线式异步电动机实现高性能调速的有效办法。用转子串反电动势来代替电阻,吸收转差功率;用双闭环控制提高系统的静、动态性能。把这种用附加电动势的方法将转差功率回收利用的调速称为双闭环串级调速。这是本文所必须研究的,也是本文的核心所在。并通过利用MATLAB软件对双闭环串级调速系统进行仿真,仿真结果表明通过双闭环串级调速系统能及时地对给定速度进行反馈,提高调速的准确性。
关键词:双闭环;串级;调速;MATLAB.
Abstract
The graduation thesis studies three-phase asynchronous motor is double loop bunch_rank speed-control of the basic principle and implement method. With wound rotor series, asynchronous motors can adjust speeds through control variables, which include electric current, electromotive force and resistance, etc. on the rotor side. Typically, the rotor current is determined by the load and cannot be adjusted freely. In contrast, adjusting rotor’s return circuit impedance tends to consume more power along with other disadvantages. Therefore, electromotive force should be the only control variable on the rotor side, which is also one of the major points research in this paper.
In summary, concatenation control system is one effective means to realize high control ability in series-wound asynchronous motors. Specifically, it is used to replace resistance with rotor’s electromotive force and absorb slip power; and to enhance the static and dynamic capabilities of the system using double closed loop. We refer to this method of utilizing additional electromotive force to recycle slip power as concatenation control with double close loop, which is also the focus of this paper. And through the use of MATLAB software on the double closed loop bunch_rank speed-control system, and simulation draw simulation diagram,the results show that by double closed loop bunch_rank speed-control system can timely given speed feedback, to improve the accuracy of speed
Keywords: double-loop; cascade; governor;MATLAB.
目录
摘要 I
Abstract II
1 绪论 1
2 串级调速的原理 3
异步电动机转子附加电动势时的工作情况 3
串级调速的功率传递