Impact of energization of large power transformer from weak source through ICT

This paper presents the impact of charging the large power transformer through a relatively weak source or grid via Interconnecting Transformer (ICT). The Generator transformer (GT) of power generating station needs to be back charged from the supply grid. Often, the permanent grid supply is not available to charge the GT at the time of commissioning and there is a practice to temporarily connect lower voltage grid through ICT. The purpose of this study is to evaluate the impact of GT charging on power system network and on ICTs and provide guidelines for proper selection of ICTs. Simulation is done on PSCAD and results are verified with recorded results observed at site during actual charging of GT.