Towards Excessive Short-Circuit Current Suppression via MMC-HVDC: A Stochastic Hybrid AC/DC Transmission Expansion Planning Approach

To overcome the limitations of conventional short- circuit current (SCC) suppression approaches in transmission expansion planning (TEP), this letter proposes a novel SCC-constrained hybrid AC/DC TEP model considering wind uncertainty. To quantify the maximum SCC contribution of MMC, a planning-oriented equivalent current source (ECS) model is developed with different fault-type-dependent magnitudes which could be directly embedded into the TEP. Then, a unified SCC formulation is proposed, integrating the SCC contribution of high voltage alternating current (HVAC) lines, synchronous generators (SGs) and superconducting fault current limiters (SFCLs). Based on the SCC formulation, the proposed stochastic model is cast as a mixed-integer linear programming (MILP) model. Numerical simulations suggest that the proposed formulations are effective in SCC modeling and suppression.