Widening the bottleneck: Increasing the utilisation of long distance AC transmission corridors

This paper considers the challenges faced by power system planners and operators with regards to heavily loaded transmission corridors which constrain power flows within the AC system, that is, they are `bottlenecks' within the AC system. Particular reference is made to long distance inter-area AC transmission lines. The addition of back-to-back HVDC schemes within these AC transmission circuits is considered and the benefits that could be realised are reviewed with some qualitative examples.