VOLTAGE SAG PROPAGATION UNDER FAULT IMPEDANCE DURING DOUBLE LINE TO GROUND FAULT ON LOW VOLTAGE DISTRIBUTION NETWORK

The voltage-sag propagation (VSP)is main issue of the power quality, which must be analyzed on different scenarios. In this paper VSP is checked during double line to ground fault under different fault impedance for distribution power network. Firstly, Mathematical modeling under symmetrical components has been done for un-balanced voltage then sequence analyzer is adopted to check different levels of voltage under unhealthy network. Secondly, the whole distribution network for double line to ground fault is adopted to check the VSP, which propagate from primary to secondary side of the transformer. In last, the VSP is visualized on different fault impedance. The simulation results can demonstrate that the voltage sag (VS) amplitude would be smaller under fault impedance and phase shift can be observed on secondary of the transformer.