Modeling Of Electrode Regulating System Of Electric Arc Furnace

It has been nearly a century about steelmaking.Especially in recent decades its development is rapid.In the modern steel enterprise,electric arc furnace has a very important position.As for electric arc furnace,due to arc length is volatile in the working process which can cause dramatic arc current and leads to serious impact to the grid energy larger influences.And the main measure to solve the problem is to build an accurate and practical mathematical model to describe the arc which is convenient to control the whole electrode system so it can reduce the energy of the impact of power grids.In this thesis,we introduced a new arc model which is described by arc length,arc current and arc conductance based on the law of conservation of energy.The new arc model can describe the external features and internal electric properties of electric arc.As for this arc model,this thesis mainly studies the influence of model parameters,the identification method of the parameters and these can prove the correctness of the proposed model on describing the electric arc.In this thesis,we build the arc furnace electrode adjustment system based on the arc model.In addition to the arc model,based on the actual electric arc furnace working environment,we discuss the model of electric arc furnace power supply system and transmission mechanism hydraulic system model.By then the electric arc furnace electrode adjustment system model is completed.Since the model is completed,we can design controller to solve the problem of electric arc furnace.As for the choice of electrode control strategy,in this thesis we discuss the constant current control,constant power control and constant impedance control.And we find that the constant impedance control strategy is much more suitable for the electrode regulating system to build controller.Then based on the constant impedance control strategy,we use PID controller to realize the electrode control system simulation which is proved in this thesis that the model can be applied in the study of the control of the arc.In order to apply design of electrode system in the actual system,we design a simulation platform for the electric arc furnace on which we can use the established model.We use WinCC and the STEP7 software of Siemens on simulation platform to build the entire electrode regulating system and by using OPC technology to achieve data of matlab and WinCC interconnected to complete the entire system.At last,through experiments we investigate the properties of arc.The realization of the function of the simulation platform can make it easier for us to study arc control system in the next step.