1、S7-300 PLC 中程序控温算法设计 I S7-300 PLC 中程序控温算法设计 Temperature Control Algorithm Design Based on S7-300 PLC S7-300 PLC 中程序控温算法设计 II S7-300 PLC 中程序控温算法设计 自动化专业 摘摘 要要 温度控制是最重要的过程控制之一， 有些温度控制过程要求按照一定的升 温、保温、降温曲线控制温度。西门子 S7-300 PLC 中 FB41 PID 控制模块有双极性输出 功能，但是该模块不具有程序控温功能。 本设计在 FB41 PID 控制模块的基础上进行的, 自主设计的程序控温算法
2、实现了夹 套锅炉的程序控温。主要包括多段温度设置曲线程序设计，升-保-降温度段控制规律的 研究和控制参数的设置。温度曲线设置采用温度-时间格式算法，本段温度设定与上段 温度设定的差值，除以本段设置时间得到温度曲线斜率，以定时中断模块 OB35 中断时 间作为设置时间的时间刻度，进行线性运算，产生设定值曲线。温度曲线设置程序输出 值作为 FB41 模块的给定值进行 PID 运算，正极性 PID 输出配合脉宽调制实现时间比例 加热控制，负极性 PID 输出调节夹套冷却水流量实现降温控制。对升-保-降温度段选用 不同控制规律和参数设置实现了程序控温，达到控温精度 0.1 ，实现了设计任务。 关键词关
3、键词 温度；双极性; PID；FB41 Temperature Control Algorithm esign Based on the S7-300 PLC Abstract: Temperature control is one of the most important process control, Some temperature control process is base on ramp rate of heating up,keeping and cooling.Siemens S7-300 PLC FB41 PID control module has dual pola
4、rity output function,but the module has no program control temperature function.This design is based on FB41 PID control module, the independent design temperature process control algorithm realize the clip set of boiler temperature control of the program.Mainly includes multistage temperature setti
5、ng curve program design, study about heating up,keeping,cooling temperature control law and preferences.Setting temperature curve is by temperature-time format algorichm, the d-value is between setting temperature and last-setting temperature , this period time is divided by d-value between setting
6、temperature and last-setting temperature ,then get the temperature curve slope. scope multiplied time get setting value curve by linear operation. Setting value is as given value of FB41 for PID operation. Positive polarity PID output and pulse width S7-300 PLC 中程序控温算法设计 III modulation realize time-proportion heating control, negative polarity PID output realize cooling control by adjusting cool water flow in clip setting. To rise-keep-cool temperature period drop choose different con
