Simultaneous measurements for analysing the flicker dissipation in meshed HV power systems

Three-phase AC arc furnaces (EAF) are sources of voltage fluctuations, harmonics and unbalances in the power supply system. Modern high-power furnaces with a rated power of 100 MVA or more are often coupled at the HV buses in order to limit these power quality impacts. However, the remaining impacts are widely spread in these cases, since they are dissipated, via the HV distribution and transmission system, to downstream MV and LV networks supplied by the HV system which is meshed and extended usually. Especially, the voltage fluctuations generated by the furnaces and dissipated in the HV network are noticed as flicker in LV light installations. The paper presents results and experiences gained by means of simultaneous field tests at different node points in a meshed 380/220/110 kV system supplying among others, electrical steel plants and urban areas as well. General conclusions are drawn concerning the dissipation of power quality impacts