Research of Voltage Sag Propagation through Transformers

Abstract

Voltage sag is one of the most critical power quality problems. This paper calculates voltage sag propagation through YNd11 and Dyn11 winding connected transformers in series using symmetrical components, thus obtaining the voltage transfer matrix. Then the voltage sag propagation of single line-to-ground fault is computed using the transfer matrix. Simulation result proves the correctness of the analytical calculation, providing reference for the further study of voltage sag influence and estimation.