Measures against voltage sags & cases from on-site data

Voltage sags are inevitable phenomenon in power system operation. Firstly impacts of voltage sags on sensitive loads in thermal power plants, petrochemical and coal chemical industry, chemical fiber industry and semiconductor industry are discussed. Then, treatment measures of voltage sag are discussed from power supply side and user side, including reducing the occurrence of line faults, reducing fault clearing time, changing power supply pattern, installing mitigating devices, adopting to AC&DC power supply scheme, and improving anti-interference performance, etc. Based on the on-site data from voltage sag treatment center of Golden Cooperate Company, cases of the above solutions are presented and analysised. Finally, treatment strategy for both power plants and other industrial users are discussed.