文档介绍：湘潭大学
硕士学位论文
改善直接转矩控制低速性能的研究
姓名:李辉
申请学位级别:硕士
专业:电力电子与电力传动
指导教师:朱建林
20050501
Abstract
This paper is to design a Direct Torque Control system, and
improve its low-speed performance.
This paper focuses on three areas:(1) building model and
simulation in MATLAB/SIMULINK;(2) Design of experimental
system platform and experiment about Direct Torque Control on the
platform;(3) Put forward to a kind of artificial intelligence in DTC
system.
It is well known that the I-N model is used in low-speed of DTC
system. Because the DTC system is a nonlinear system,and I-N mode
strongly depends on parameters of motor . Robust of the system isn't
so good .As result, the low speed of DTC system isn't good and the
speed of motor is pulsant. This hinders the development of DTC
system.
U-I model is simple and good robust,meanwhile it is easily
realized. Because integral of the error is large in low speed,the flux
isn't accurate. In this paper U-I model is much researched and a new
flux-fuzzy control method is proposed. Round flux、hexagon flux and
fuzzy control are experimented in this system. The proposed theory is
proved by results of experiments.
At last the test prototype system is implement on a Digital signal
Processor (TMS320F240). The real time control software is written in
assembly language. Three methods have been experimented on a
180w motor without load.
key word: direct torque control; fuzzy control; DSP ; flux ;
AC motor
湘潭大学硕士学位论文
1 前言
交流电动机调速技术的发展和现状
在用电系统中,电动机作为主要的动力设备而广泛地应用于工
农业生产、国防、科技及社会生活等各方面。电动机负荷约占总发
电量的60% ~ 70%,成为用电量最多的电气设备。
电动机作为把电能转换为机械能的主要设备,在实际应用中,
一是要使电动机具有较高的机电能量转换效率;二是根据生产机械
的工艺要求控制和调节电动机的旋转速度。电动机的调速性能如何
对提高产品质量、提高劳动生产率和节省电能有着直接的决定性的
影响[1]。
根据采用的电流制式不同,电动机分为直流电动机和交流电动
机两大类[1]。众所周知,直流电动机的转速容易控制和调节。因此,
20纪80年代以前,在变速传动领域中,直流调速系统一直占据主导地
位。但是,由于直流电动本身结构上存在机械式换向器和电刷这一
致命弱点,这给直流调速系统的开发和应用带来一系列限制,如:
①机械式换向器表面线速度及换向电流、电压有一极限容许值,
这就限制了单机的转速和功率。如果要超过极限容许值,则大大