Flicker emission assessments and a new method based on RMS measurements

Under the scope of the IEC technical report 61000-3-7, the principles to assess flicker emission limits for the connection of fluctuating loads to the public network power system have been outlined. This technical report gives also the definition of the flicker emission level. But this report does not explain how to measure and assess the flicker emission level. Actually, because of the existence of background flicker, the flicker emission level of a customer cannot be determined from a simple voltage measurement at the PCC (point of common coupling). System operators need adequate methods to carry out flicker assessment. The present paper gives review and explication of some existing methods in the literature in flicker contribution studies, particularly, the methods based on direct on-line measurement. Different assessment techniques described will be completed by our case studies. A simple and novel method for flicker source assessment has been studied and presented. This method needs small volume of on-site data recordings and it is based on simulation with recorded customer load variation and simplified IEC flicker meter emulator. The method makes it possible to assess flicker emission with fast monitoring electric values and it is adaptable for system operator to perform flicker assessment with their available monitoring data.