自适应变频调速棉田灌溉系统设计与仿真

Design and Simulation of Adaptive Frequency Conversion and Speed Regulation Irrigation System for Cotton Field

新疆是全国最大的优质商品棉生产基地,灌溉在棉花生产中占据着极其重要的地位。目前,兵团多地传统的变频调速系统大多采用经典的PID控制或模糊控制,适应性不强、控制精度较低,且参数整定、调试麻烦。为此,基于模型参考自适应理论提出了一种变频恒压调速系统的控制方法,根据变频调速系统的结构(包括PLC、变频器、电动机、水泵、流量计等),建立了该系统的数学模型,详细论述了采用李雅普诺夫稳定性理论实现模型参考自适应控制的过程,并求解自适应控制器和相应的控制率。最后,利用MatLab/Simulink软件对模型参考自适应控制下的系统进行仿真分析,并与经典PID控制系统进行对比分析,结果表明:控制对象输出信号yp能够很好地对参考模型信号yr进行跟踪,并具有更好的响应速度、运动精度及抗干扰能力。

Xinjiang is the country's largest high-quality commercial cotton production base,and irrigation occupies an extremely important position in cotton production.At present,the Corps often uses traditional frequency conversion speed regulation systems,and most of them use classic PID control or fuzzy control.The adaptability is not strong,the control accuracy is low,and the parameter setting and debugging are troublesome.Aiming at the control problem in this irrigation system,this paper proposes a control method of variable frequency constant pressure speed regulation system based on model reference adaptive theory.In the system design,Lyapunov theory is used to solve the adaptive controller and the corresponding control rate.The structure of the frequency conversion speed regulation system is introduced in this article,including PLC,frequency converter,motor,water pump,folwmeter,etc.The mathematical model of the system is established,and the process of implementing model reference adaptive control using Lyapunov stability theory is discussed in detail.Using MATLAB software to simulate and analyze the system under model reference adaptive control,the results show that the output signal yp of the control object can well match the reference model signal yr,and has better response speed,motion accuracy and anti-interference ability.