文档介绍：摘要
直流调速系统具有调速范围广、精度高、动态性能好和易于控制等优点,所以在电气传动中获得了广泛应用。为了获得可调的直流电压,利用电力电子器件的完全可控性,采用脉宽调制技术,直接将恒定的直流电压调制成可变大小和极性的直流电压作为电动机的电枢端电压,实现系统的平滑调速,这种调速系统就称为直流脉宽调速系统。
本设计建立了基于脉宽调制的转速、电流双闭环直流调速系统的数学模型,并分析了系统的基本原理及其静态和动态性能。然后按照自动控制原理,对双闭环直流脉宽调速系统的设计参数进行分析和计算。在理论分析和仿真研究的基础上,采用MATLAB软件对直流电动机双闭环直流脉宽调速系统进行计算机仿真,并查看仿真波形,以此验证设计的调速系统是否可行。本文在MATLAB环境下建立了双闭环直流脉宽调速系统模型,并对系统的性能指标进行了仿真测试,与此同时建立了一套单闭环系统进行对比测试,表明所设计的双闭环脉宽调速系统运行稳定可靠,具有较好的静态和动态性能,达到了设计要求。
关键词:直流调速系统;脉宽调制;转速电流双闭环;仿真
Abstract
Being widely used in electrical transmission, DC (Direct Current) speed control system has the advantages of wide speed range, high accuracy, good dynamic performance, and it is easy to control. To achieve adjustable DC voltage, using the full controllability of the power electronic devices and pulse width modulation technology, a constant DC voltage is modulated directly into variable size and polarity, which is used as the motor armature terminal voltage to achieve smooth speed control of the system, this speed control system is known as the DC PWM (Pulse-Width-Modulation) speed control system.
A mathematical model based on speed and current double closed loop DC speed control of PWM is established in this paper and its principle, static and dynamic performance are analyzed. Then the system parameters are designed, analyzed and calculated according to the automatic control theory. Also, the speed control system of DC motor double closed loop is simulated by use of MATLAB, and the simulation waveforms are viewed in order to verify whether the design of the speed control system is feasible or not. A double closed loop DC PWM System model is established in the MATLAB environment, and the system performance is simulated and tested. At the same time, a single closed loop system is also established to carry out parison test, indicating that the operation of the design of double closed loop PWM System is stable and reliable and the system has a good static and dynamic performance, which can meet the design req