【作者】 张锐锋；

【导师】 余强；

【作者基本信息】 东北大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 LF钢包精炼炉是国内外最为流行的炉外精炼方式。钢包炉通常采用三相交流电弧加热。随着直流电弧炉技术的发展,钢包炉也采用直流电弧加热,并具有多方面的优点,尤其是在耐火材料消耗指数方面有着极大的优势。本项目采用炉底阳极形式的直流LF钢包精炼炉,是将一根石墨电极控制在具有一定电阻的熔渣层中,使石墨阴电极与金属熔池间保持一定的距离,当直流电压加在电极上时,阴极产生电弧。直流电通过阴阳极、电弧、电渣构成回路,达到对钢水加热的目的。本文针对某钢铁集团技术中心实验工厂新建项目——2吨直流LF精炼炉系统,采用西门子S7—300及ET200S系列PLC设计了基于PROFIBUS—DP的分布式计算机控制系统,实现了对整个精炼过程的控制。利用西门子公司的WinCC组态软件,完成上位机监控软件组态,实现现场数据实时记录和监控。设计了冶炼计时、记录查询、读写工艺参数等具有Windows风格的动态操作画面。在LF炉内钢水的加热速度和温度完全由电流控制系统和电压调节系统决定。电流控制通过调节石墨电极升降速度和插入深度实现,电压控制通过调节直流整流电源的输出电压实现。然而,电极插入深度既影响电流大小,同时也影响供电电压的大小,形成较强的耦合作用。本文针对这一现象,同时考虑到LF炉非线性、时变、没有准确数学模型的特性,尝试设计了一种PID神经网络解耦控制器。它是把传统PID方法与神经网络相结合,对LF的电流电压进行解耦控制,从而使被控对象具有良好的动、静态性能,满足控制要求。论文详细地介绍了直流LF炉的生产工艺流程、控制系统的总体结构设计、PLC系统选型、控制软件的编制等内容。更多还原

【Abstract】 The ladle furnace is the most popular refine way in the domestic and foreign. The ladle furnace usually uses the three phase AC arc to heat. Along with the development of the DC arc furnace technology, the ladle furnace also uses DC arc to heat, and has the various merits, has the enormous superiority in particular in the fire-proof material consumption index aspect. This project uses single bar bottom positive electrode, which takes a graphite electrode in the slag level that has the certain resistance, maintains the certain distance between the graphite negative electrodes and the metal molten bath. When DC voltage is added to the electrode, the negative electrode produces the electric arc. The DC constitutes loop through the electrode, the electric arc and the electricity slag, to achieve the goal to heat up the molten steel.This article aim at some Iron & Steel Corporation Steel Corporation group technology center pilot plant newly built project of 2t DC ladle furnace system, design distributed computer control system which is based on the PROFIBUS-DP. It controls the entire smelting process by using Siemens S7-300 and ET200S series PLC. Using Siemens’s WinCC configuration software, to complete monitoring software configuration, to realizes the field data real-time recorded and the monitoring. Having designed smelting time, recording inquiry, read-write parameter and so on. Those have the dynamic operation picture of the Windows style.In the ladle furnace, heating speed and the temperature of the molten steel completely lie on the electricity control system and the DC voltage control system. The electricity control is plying by the rise and fall speed and the infixed depth of graphite electrode. The voltage control is plying by the output voltage regulation on the DC power supply. But the infixed depth of graphite electrode make effect on the electricity, at the same time it also influenced the voltage. So it made great coupling. The thesis aim at the bad control impact made by the voltage and the electricity coupling in the DC ladle furnace, take into account the characters of the ladle furnace:non-linear, time-variation, inaccurate mathematic model. Design one kind of PID neural network decoupling controller. It combined the conventional PID method and the neural network, decoupling the electricity and the voltage of the ladle furnace, accordingly to have good dynamic and static characteristic, meet the control demand.更多还原