Determination of flicker contributions of loads supplied from a point of common coupling at an electrical system

In this paper, a new method is proposed to determine the individual flicker contributions of loads supplied from a point of common coupling (PCC) at an electrical system. The proposed method decouples the individual contributions of the loads from the interconnected system, by using their reactive current components and the short-circuit system impedance. It is shown that the individual flicker contributions of the loads are mainly due to the reactive component of the currents. Since the computational complexity of the method is low, it is appropriate for online calculations and it can be employed as a flicker-contribution-meter. The proposed method is used at a PCC which supplies multiple electric arc furnace (EAF) plants for the validation of results. The most important advantage of the method is that, in addition to the IEC flickermeter, it decouples the individual contributions of the sources and makes a numerical assessment possible so that necessary countermeasures can be taken.