The Challenges of standards related to voltage sag

Voltage sag is an inevitable power quality problem in power system. This paper reviews and summarizes IEEE (Institute of Electrical and Electronics Engineers), IEC (International Electro technical Commission) and Chinese standards related to voltage sag, mainly including voltage sag definition, monitoring, indices evaluation, voltage sag tolerance test of sensitive equipment and governance measures. This paper also summarizes the differences and focuses of each standard and analyzes the problems that are still worthy of improvement in the existing standards so as to provide reference for scientific understanding and solving the voltage sag problem.