The research and solutions of voltage sag in Shenzhen power gris under the high load growth

Voltage sag, swell, asymmetry, flicker and harmonics in distribution system, made by faults in power system or the increasing use of large numbers of non-linear and impactive loads, will result in abnormally and causing huge economic losses. Power quality is an issue that is becoming increasingly important to electricity consumers at all levels of usage. Because of increases in electricity and the loads, with using sensitive equipment and non-linear loads are now more commonplace in both the industrial/commercial sectors and the domestic environment, there are serious power quality of the transmission-line system of electric power of SHENZHEN district, especially voltage sag. This paper use the theory and PSCAD/EMTD simulating program to analysis the power quality of transmission-line system of electric power of SHENZHEN district, finally give solutions to solve the problem.