基于PLC实现的三相异步电动机精确角度控制系统

发布时间：2018-09-13 06:04

【摘要】：角度控制是工业控制中常见的一种控制方式。角度控制一般大都采用步进电机作为控制对象,而控制器件也大都采用微型计算机或者数字信号处理器即DSP,但是步进电机的功率容量受到限制,微处理器和DSP也对环境有特殊要求,这对于在远离城市和野外操作的石油开采钻井造成一定的困难,而钻井又是石油开采中的重要环节。能否采用驱动容量不受限制的普通异步电动机作为控制对象,采用可靠性高和工作环境要求低的可编程序控制器即PLC作为控制手段实现精确角度控制,一直是人们追求的目标。本文通过实际科研项目,对基于PLC实现的三相异步电动机精确角度控制系统进行了研究,取得了较好的效果。首先,介绍了三相异步电机的动态数学模型,以及坐标变换原理。针对异步电动机具有非线性、强耦合、多变量的特性,采用高动态调速性能的矢量控制技术,并详细介绍了矢量控制原理以及该控制技术需要用到的电压空间矢量脉宽调制技术(SVPWM)。同时利用矢量控制技术设计了一种基于模糊控制的异步电机精确角度控制系统来实现电机旋转角度的精确控制。其次,利用MATLAB/Simulink软件对系统进行建模与仿真,根据三相异步电动机的数学模型和矢量控制技术以及模糊控制的理论知识,对系统的各个部分进行建模仿真,并进行大量的仿真实验。通过仿真分析论证控制算法的可行性及正确性,为搭建硬件平台做出理论依据。最后,搭建了由西门子S7-315型号的PLC以及西门子S120驱动系统构成的精确角度控制系统。其中PLC通过PROFIBUS-DP,总线与S120实现通讯功能,利用STEP7软件对系统硬件进行组态,并对S120驱动系统进行参数配置以及编写整个系统的程序。通过对实验数据的分析,达到了预期的要求。
[Abstract]:Angle control is a common control method in industrial control. The angle control usually uses stepping motor as the control object, and the controller also mostly uses microcomputer or digital signal processor (DSP,), but the power capacity of step motor is limited. Microprocessors and DSP also have special requirements for the environment, which makes it difficult for oil drilling which is far from city and field operation, and drilling is an important link in oil production. Whether we can use ordinary asynchronous motor with unlimited driving capacity as control object, and use programmable controller (PLC), which has high reliability and low requirement of working environment, as control means to realize precise angle control, has always been the goal that people pursue. In this paper, the precise angle control system of three-phase asynchronous motor based on PLC is studied, and good results are obtained. Firstly, the dynamic mathematical model of three-phase asynchronous motor and the principle of coordinate transformation are introduced. In view of the nonlinear, strong coupling and multivariable characteristics of asynchronous motor, the vector control technology with high dynamic speed regulation performance is adopted. The principle of vector control and the voltage space vector pulse width modulation (SVPWM).) technique are introduced in detail. At the same time, an accurate angle control system of asynchronous motor based on fuzzy control is designed by using vector control technology to realize the precise control of motor rotation angle. Secondly, MATLAB/Simulink software is used to model and simulate the system. According to the mathematical model and vector control technology of three-phase asynchronous motor and the theory knowledge of fuzzy control, every part of the system is modeled and simulated. And a large number of simulation experiments are carried out. The feasibility and correctness of the control algorithm are demonstrated by simulation analysis, and the theoretical basis for building the hardware platform is made. Finally, a precise angle control system composed of Siemens S7-315 PLC and Siemens S120 drive system is built. The communication function between S120 and PLC is realized through PROFIBUS-DP, bus. The hardware of the system is configured by STEP7 software. The parameters of S120 drive system are configured and the whole system program is written. Through the analysis of the experimental data, the expected requirements have been achieved.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM343.2;TP273

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