Voltage sags: their impact on the utility and industrial customers

This paper describes the impact of voltage sags on the electric utility and industrial customers. Several utility measures are presented to minimize the customer's exposure to voltage sags. These measures cannot completely eliminate the impact of voltage sags on sensitive equipment, however. A case study is presented in this paper that includes measurement results that were used to characterize the voltage sags experienced on the utility system and in the industrial facility. Simulation results used to develop "area-of-vulnerability curves" for the industrial facility, mitigation equipment that was employed to improve the sensitive equipment's ridethrough capability and the lessons learned from the systems approach analysis are presented.