1、 PDF外文：http:/ 中文5373字毕业设计（外文翻译） 英文题目 Realization of Neural Network Inverse System with PLC in Variable &nb
2、sp; Frequency Speed-Regulating System 中文题目 PLC 变频调速的网络反馈系统的实现 系 （院） 自动化系 专 业 电气工程与自动化 学生姓名
3、; 00 学 号 2009022221 指导教师 李思光 职 称 &nbs
4、p; 讲 师 二 一三 年六月 滨州学院本科毕业设计 (外文翻译 ) 1 Realization of Neural Network Inverse System with PLC in Variable Frequency Speed-Regulating System The variable frequency speed-regu
5、lating system which consists of an induction motor and a general inverter, and controlled by PLC is widely used in industrial field. However, for the multivariable, nonlinear and strongly coupled induction motor, the control performance is not good enough to meet the needs of speed-regulating. The m
6、athematic model of the variable frequency speed-regulating system in vector control mode is presented and its reversibility has been proved. By constructing a neural network inverse system and combining it with the variable frequency speed-regulating system, a pseudo-linear system is completed, and
7、then a linear close-loop adjustor is designed to get high performance. Using PLC, a neural network inverse system can be realized in actural system. The results of experiments have shown that the performances of variable frequency speed-regulating system can be improved greatly and the practicabilit
8、y of neural network inverse control was testified. 1. Introduction In recent years, with power electronic technology, microelectronic technology and modern control theory infiltrating into AC electric driving system, inverters have been widely used in speed-regulating of AC motor. The
9、variable frequency speed-regulating system which consists of an induction motor and a general inverter is used to take the place of DC speed-regulating system. Because of terrible environment and severe disturbance in industrial field, the choice of controller is an important problem. Neural network
10、 inverse control was realized by using industrial control computer and several data acquisition cards. The advantages of industrial control computer are high computation speed, great memory capacity and good compatibility with other software etc. But industrial control computer also has some disadva
11、ntages in industrial application such as instability and fallibility and worse communication ability. PLC control system is special designed for industrial environment application, and its stability and reliability are good. PLC control system can be easily integrated into field bus control system w
12、ith the 滨州学院本科毕业设计 (外文翻译 ) 2 high ability of communication configuration, so it is wildly used in recent years, and deeply welcomed. Since the system composed of normal inverter and induction motor is a complicated nonlinear system, traditional PID control strategy could not meet the requireme
13、nt for further control. Therefore, how to enhance control performance of this system is very urgent. The neural network inverse system is a novel control method in recent years. The basic idea is that: for a given system, an inverse system of the original system is created by a dynamic neural networ
14、k, and the combination system of inverse and object is transformed into a kind of decoupling standardized system with linear relationship. Subsequently, a linear close-loop regulator can be designed to achieve high control performance. The advantage of this method is easily to be realized in enginee
15、ring. The linearization and decoupling control of normal nonlinear system can realize using this method. Combining the neural network inverse into PLC can easily make up the insufficiency of solving the problems of nonlinear and coupling in PLC control system. This combination can promote the applic
16、ation of neural network into practice to achieve it full economic and social benefits. In this paper, firstly the neural network inverse system method is introduced, and mathematic model of the variable frequency speed-regulating system in vector control mode is presented. Then a reversible an
17、alysis of the system is performed, and the methods and steps are given in constructing NN-inverse system with PLC control system. Finally, the method is verified in experiments, and compared with traditional PI control and NN-inverse control. 2. Neural Network Inverse System Control Method The basic
18、 idea of inverse control method is that: for a given system, an-th integral inverse system of the original system is created by feedback method, and combining the inverse system with original system, a kind of decoupling standardized system with linear relationship is obtained, which is named as a p
19、seudo linear system as shown in Fig.1. Subsequently, a linear close-loop regulator will be designed to achieve high control mathematic model of the variable performance. Inverse system control method with the features of direct, simple and easy to understand does not like differential geometry method, which is discusses the problems in
