Research On Key Technologies Of Reactive Power Compensation And Harmonic Suppression In Ac Arc Furnace

With the continuous advancement of electric arc furnace steelmaking technology,it's getting used more and more widely in metallurgical enterprises.Due to electric arc furnace's typical time-varying nonlinear characteristics,it will cause enormous impact on the power supply system,causing multiple problems such as voltage flicker,voltage fluctuations,harmonics,and power factor reduction.Aiming at the problem that the static var compensator(SVC)is not effective in suppressing voltage flicker,filtering harmonics,and the cost of static var generator(SVG)is too high,this paper come up with a low-cost composite reactive power compensation model(TSC+TCR+SVG)is proposed.The compensation model uses the TSC+TCR module to complete the preliminary compensation,SVG is responsible for subsequent fine compensation and suppression of voltage flicker,which would minimize costs and improve performance through working cooperatively;The control strategy uses a SVG sub-control system with direct current control,coming up with a selective configuration strategy based on historical state is proposed for TSC+TCR.Constructing complete system simulation model to further verify the rationality of the composite reactive power compensation model and the effectiveness of the control strategy,A complete system simulation model was constructed and verified,The results show that the proposed control strategy performs well,The hybrid reactive power compensation device also has a better compensation effect.An active power filter(APF)is a power electronic device for dynamically suppressing harmonics,This paper takes the series active power filter as the research object and makes improvement on the harmonic suppression scheme and control method for the active filter in the large-capacity load.Firstly,proposing solution based on the analysis of reactive power compensation and harmonic suppression,Additionally,optimizing the influence the gain coefficient on the filtering effect and adding delay compensation design.Constructing a complete composite control strategy circuit based on the result and verifying by building system simulation model.The simulation results gained show the correctness and effectiveness of the whole system.Finally,a static model of the electric arc furnace is established for the electric power quality problem of the electric arc furnace.On this basis,the improved genetic algorithm(PSO)is used to identify the parameters in the static model of the electric arc furnace.The identification results are in good agreement with the measured data,which lays a model foundation for the study of electric power quality comprehensive management of electric arc furnace grid.Through reasonable layout of reactive power compensation and harmonicsuppression module to eliminated the load voltage fluctuation of the electric arc furnace and to suppress the generation of even harmonics and some odd harmonics of the electric arc furnace from the source,then applying the active filter is used to further eliminate the arc furnace harmonics for the purpose of comprehensive compensation.Finally,using the simulation platform,the electric arc furnace power grid model and the final comprehensive compensation system model are built.By analyzing the system reactive power change,power factor waveform and grid current and voltage waveform of the integrated compensation system before and after the electric arc furnace grid is put into operation,fully verifying the rationality and effectiveness of the proposed governance plan.