Series compensation system modelling, protection challenges and recommendations for the anglo-scottish interconnection

Series compensation on the Great British transmission system has been a subject of discussion in recent years. Active work has taken place in collaboration with the utilities involved and protection manufacturers to understand the effects of such series compensation devices on the primary and secondary system including protection equipment. The authors of this paper working for their respective organizations have been involved in such studies. The results of such a study have been discussed in detail within this paper. Additionally the authors have also brought out some of the recommendations that have been made consequent to the detailed modelling studies. Importantly, this paper aims to bring out the challenges of having series compensation devices in such a tightly meshed and interconnected system with relatively short transmission lines, particularly focusing on the impacts of the existing protection philosophy.