A new voltage sag generator base on power electronic devices

Abstract

With increased wind power penetration level, new grid codes generally require the wind power system be able to stay connect during a grid voltage sag. Voltage sag generator (VSG) is a kind of device used to simulate the fault condition so as to verify the reliability and stability of wind power system during low voltage ride-through (LVRT). Firstly, two existing VSG topologies which are based on the variable transformer-switch and back-to-back converter are briefly reviewed. To overcome their deficiencies, a new VSG based on transformer and power electronic devices is then proposed. The operating principle is explained and the design details are given. Finally, simulation and experiments are carried out to validate the performance of this VSG.