Research on propagation regularity of voltage sags in power system

Voltage sag is a major power quality problem, which could disrupt the operation of voltage sensitive equipment. The fault in transmission and distribution lines of the power system creates voltage sags. It´s important to analyze the voltage sags caused by faults in high voltage systems to solve the voltage sag problems of customers. A fully digital power system simulation tool, EMTDC/PSCAD, was applied to build a system model of a large power customer, a large quantity of simulating calculation about voltage sags was carried out. It demonstrates the possible application of the platform and affordable means to study different cases of these problems.