A review of flicker objectives related to complaints, measurements, and analysis techniques

Recent anecdotal and technical evidence exists regarding the difficulty in coordinating measured flicker levels with customer complaints. This potential poor correlation is particularly observed with regard to measurements made in HV and EHV systems and, to a lesser extent, to measurements made in MV systems. A recently completed report from CIGRE/CIRED C4.07 documented measured levels of Pst (or Plt where used) above planning levels while no complaints were received from LV users. Similar reports were also received throughout the work of CIGRE/CIRED C4.103 in revising IEC 61000-3-7, culminating in new annex material offering possible options for managing this situation. To develop further understanding of the possible causes of the observed lack of correlation, CIGRE/CIRED C4.108 was convened first in 2007. This paper documents the preliminary findings of that group.