Estimating the annual frequency and cost of voltage sags for customers of five Finnish distribution companies

Abstract

Frequency and cost of voltage sags for customers of five Finnish distribution companies were evaluated. For voltage sag frequency calculations the method of fault positions was applied. Only sags caused by short circuit faults in medium voltage distribution networks were considered. Sag frequency below considered 50% magnitude showed quite low numbers. However the cost related to this sag magnitude revealed that voltage sags are a relevant power quality issue having economic significance.