On the appropriate monitoring period for voltage flicker measurement in the presence of distributed generation

Voltage flicker or voltage fluctuations are considered a major power quality problem causing temperature rise, generators and motors overloading and affecting humans through the irritating light flicker. It is expected that the level of voltage flicker will increase due to the increased penetration of distributed generation (DG) in the distribution system. Site monitoring is required to make sure that the level of voltage flicker is within the allowed limit. In order to determine the appropriate monitoring period for voltage flicker measurement while considering DGs, two case studies were considered in the paper; 1 week and 1 day monitoring periods. The results reveal that a monitoring period of 1 week may be very long especially in the presence of DG and it may hide valuable information. On the other hand a 1-day monitoring period is more appropriate in these situations. Therefore it is recommended to use 1-day monitoring period instead of 1 week especially in the presence of DG.