Literature Survey on Mitigate voltage sag and swell in transmission line by using SEN Transformer

Abstract

 Power system transmission lines are becoming more heavily loaded and this affects system security and stability. Power flow control is essential to ensure preserving lines loading security, mange the congestion of power system, alleviate line overload, and semi-equally utilize the available transmission lines as far as possible. The traditional technology of transformer and tap changer is used to implement this novel technique. A “SEN” Transformer (ST) uses transformer and tap changers that are traditionally used to build a voltage-regulating transformer. The technology of transformer and tap changer is proven to be reliable and cost-effective when compared with the emerging technology of VSC. The ‘SEN Transformer’ (ST) contains a number of tapped, magnetically-coupled, series transformer windings that provide independent active and reactive power flow control in a transmission line similar to a Unified UPFC. A transient model of the ST, using a  hybrid  transformer modeling approach  is described in this paper