A fast and automatic candidate lines selection approach for transmission expansion planning

Traditionally, candidate lines for the transmission expansion planning are manually selected, which faces great challenges in terms of multi-regional planning and large penetration of renewable energy sources (RES). In this paper, an approach is proposed to select candidate set of transmission lines automatically. The utilization level of RES can be ensured by the created candidate set. Through the definition of congestion buses, the size of promising candidate lines is greatly reduced. Moreover, to make a trade-off between the integrity of the candidate set and the computation time, linear relaxation is applied. Two case studies verified the performance of the proposed approach.