FUZZY BASED AUTOMATIC CONTROL SYSTEM FOR AN ELECTRIC ARC FURNACE

摘要

This paper deals with an artificial intelligent based system using fuzzy logic controller to optimise the utilization of an electric arc furnace. The main objective of this system is to control the electrode movement to optimise the power consumption. In electric arc furnace, three graphite electrodes carry the three-phase current into the furnace. An electric arc is generated between electrode and the metal charge, which gives out heat. Fuzzy logic controller is used to maintain proper length of arc through out the melting cycle. Modular based hardware design consists of CPU, input card, output card, control & protection card and communication card. Software design consists of fuzzification using input and output fuzzy subsets, determination of membership function and strengths, fuzzy control, fuzzy rulebase and defuzzification to form a crisp set using C++ programming language. All the input signals, control and interlocks were simulated using computer and the outputs were studied. Pre-commissioning work was carried out using fuzzy controller to optimise the arc length to get optimum power. The response was found to be satisfactory when compared with the conventional control system. The advantages of this fuzzy control system are 1. Improved refractory life, increased production due to shorter melt down & low settling time. Improved process monitoring. Less energy consumption Elimination of over loading the furnaces and Reduction in consumption of carbon electrode.