【作者】 齐勇；

【导师】 程平； 王春林；

【作者基本信息】 武汉理工大学 ， 控制工程， 2011， 硕士

【摘要】 随着科学技术的发展,生产过程中的电气自动化水平不断提高,对于电动机起动方式的选择成为专业人员关注的焦点。液态软起动系统的电阻可塑性非常好,并且具有操作简单,运行可靠,维护方便,成本低以及可连续多次起动的优点,广泛应用在化工、冶金、建材以及轻工业等领域。本文通过对液态软起动系统的分析,确定了总体的架构设计。针对液态软起动系统的特点和所要实现的基本功能,选用三菱公司的型号为FX2N-64MR-001的可编程序控制器作为液态软起动控制系统的控制核心。并且加入可触摸式的液晶显示屏来显示各项信息,使整个系统在使用时更加方便。对于液态软起动系统的硬件部分,包括主电路、控制电路、开关量输入输出电路、人机交互单元,其中控制电路又包括信号检测电路、V/F转换电路、信号产生电路、多谐振荡器电路、驱动电路、隔离电路等。将各个功能模块分开设计,最后综合在一起,大大缩短了硬件设计周期,也为后期的调试和维修提供了方便。对于液态软起动系统的软件部分,首先设计了整个系统的控制流程,由于整个系统比较复杂,所以根据系统中各个部分实现的功能不同将整个系统分为数个子模块,包括初始化模块、采样检测模块、主程序模块、自动控制模块、手动控制模块等分别进行编程。分块式的设计模式不仅使整个软件的设计思路更加清晰,也减少了程序的出错率,并且在调试过程中也为操作人员提供了很多方便,提高了整个程序的可维护性和复用率。在液态软起动系统的控制过程中,本设计采用PID控制算法和模糊控制算法交替控制的控制算法,将二者融合在一起,充分利用了PID算法和模糊算法的优点进行分段控制,从而得到比较理想的静态特性和动态特性。最后采用Proteus软件对V/F变化电路进行仿真,仿真过程中通过改变输入电压Ui的大小,得到不同频率的波形,进而计算出相应的频率值,通过这些数据作出了电压频率变换图。对于系统的整体仿真采用了Matlab软件,搭建模型并输入相应的参数值后,得到了直接起动与软起动的仿真波形,证明液态软起动系统能够完成预期的要求和目的。更多还原

【Abstract】 With the development of science and technology, the automatic level of the production process improves constantly, how to start the motor is becoming a focus of professionals.The resistance of the liquid resistance soft start system has good elasticity.It has many advantages,such as easy to operate、reliable pump performance、easy service、low cost sensor element,ect. It has a widely used in chemical engineering、metallurge、construction、light industry fields.By means of the liquid resistance soft start system,the dissertation designed the global structure.Aiming at character and function of the liquid resistance soft start system,it utilized the FX2N-64MR-001 PLC of MITSUBISHI as the controlling core of the liquid resistance soft start system in this dissertation.Then I devise the hardware part，it include the main circuits、control circuit、Human-computer Interface.To separated the design of each module,and finally integrated together, not only greatly reduced the hardware design cycle,but also more convenient for the debugging and maintenance.The entire software part is divided into parts,according to the different function. Sub-block model made the entire software design more clearly,the program’s error rate lower,and also provided a lot of convenience to in the debugging process.In the control process of the liquid resistance soft start system, the fundamental algorithm uses the pid control combining vague control algorithms. Use their advantages for the segmented control.So then we can get the perfect feature.Finally,took Proteus as the simulation software of the V/F circuit,by changing the values of the voltage Ui,we can got the chart of voltage-frequency conversion.For the overall system simulation using Matlab software, we got the different waveforms from a direct-start system and a soft start-system,the result proved that the liquid soft-start system can meet requirements and objectives that are expect.更多还原