Optimization Technology Research Of Power Quality For AC Electric Arc Furnace

The electric arc furnace (EAF) which has characters like high quality of the smelting,reliable operation, low investment cost is important smelting equipment in modern iron andsteel enterprises. With the development of technology, more and more electric arc furnace thathas large capacity and high power has been already put into production. However, due to theirown working environment and characteristics, power quality problems that caused by EAF,such as harmonics and flicker, etc. have seriously affected on the quality of power supplynetwork. EAF has become one of the main pollution of power grid. With the expanding anddeepening power quality requirements of the power users, power quality improvement hasbecome a guarantee for the safe operation of power system.First, in this paper, introduced the main components and every part’s circuit model of ACelectric arc furnace’s electrical system, and then the core part which is called time-varyingresistance in this paper of the EAF is built, it is based on the energy balance, combined withresults of previous studies. In the simulation, this model is encapsulated into subsystems andadded into the electrical system. Simulation results show that this electric system canaccurately approximate the characteristics of actual AC EAF. This model has laid a goodfoundation for solving power quality issues.Then, through the harmonic analyze of this model, find out the changes of power qualityproblems which caused by AC EAF in different periods of smelting. On this basis, acompensator package was proposed which is based on static vat compensator (SVC), to solvethe problem that caused by EAF, like voltage fluctuations and flicker, low power factor, etc.Next, the working principle and compensation characteristics of traditional SVC are analyzed.And then, designed the SVC system with the characteristics of actual EAF, and verified itsreliability by simulation. In this article, the control signal detection methods of SVC havebeen described and validated. Finally, compare the compensation effects of different controlsystem, select the best one.