模糊PID算法在双闭环温控系统中的应用

摘要

在工业生产中,为克服温度控制系统的大滞后特性,构建了温度反馈和电流反馈的双闭环控制系统.上层是以PLC为控制核心的温度-电流设定值控制系统,下层是以DPS为控制核心的电流设定值-负载电流值控制系统,通过调节硅钼棒负载功率以调节钟罩炉温度.重点讨论了上层控制系统的控制策略,模糊自适应整定PID算法的选用和实现方法.通过现场测试,系统具有良好的稳定性和控制精度.%In order to reduce the high hysteresis of the temperature control system in industry application, the double-loop control system is constructed, which combines temperature feedback and current feedback. The upper system is temperature-current set point controlling, which bases on PLC module, and the lower is current set point-load current controlling, which based on DSP chips. The inner temperature of the bell-type furnace is controlled by adjusting the load power of Si-Mo sticks. The focus of the article is to discuss the controlling strategy of the upper control system, and the selection and execution of self-adaptive fuzzy PID algorithm. The field measurement result shows the system is very stable and its control is accurate.