基于S7-300PLC的电加热器模糊控制编程实现

The Program of Fuzzy Logic Control about Electric Heater Based on S7-300 PLC

针对某实验装置中电加热器大时滞、非线性、难以建立精确数学模型等特点,提出采用模糊策略对其控制的方法,并基于S7-300PLC对模糊控制策略的实现进行了分析设计,给出了关键步骤的梯形图程序.通过实验结果分析比较了模糊控制和传统控制策略的控制效果.结果表明,此方法较好地解决了电加热器控制的大时滞、非线性等特点,且PLC实现简单实用,取得了良好的调节品质.

According to the features of the long time lag,nonlinearity and the precise mathematic model that is hard to build in electric heater,a fuzzy logic control method applied to the system is presented and the realization of the fuzzy logic control algorithm is analyzed and designed based on $7 -300 PLC. At the same time, the pivotal LAD program is given. According to the experiments, the control effects of fuzzy control and traditional control have been analyzed and contrasted to each other. The result shows that the method resolved the long time lag and nonlinearity of electric heater control,and that the algorithm is realized with PLC simply with a better control quality.