Influence of the current control loops of DC arc furnaces onvoltage fluctuations and harmonics in the HV power supply system

摘要

It is necessary, to an increasing extent, to take controllers andcontrol loops into consideration in mathematical modelling andsimulations for power quality studies. DC arc furnaces belong to thoseelectric loads which network behaviour is essentially influenced bycontrol processes. Rated at more than 100 MVA, these furnaces causevoltage fluctuations and harmonics in the HV power system. Based onexperiences of onsite measurements at several plants, a mathematicalfurnace model was completed by implementing phase lock-loop and DCcurrent control loops. The paper shows what influence is exerted toharmonics and flicker severity by the DC furnace current control. Casestudy calculations are compared to measurement results. It is shown thatit is not sufficient to simplify or neglect the control loops in suchcases