Development of Operation Strategies of MIDC Systems for Mitigating Renewable Energy Curtailment in Korean Power System

With the growing integration of renewable energy (RE), there is an increasing emphasis on system flexibility, underscoring the need for a high-voltage direct current (HVDC) infrastructure. In Korea, multi-infeed HVDC (MIDC) systems asynchronously interconnect the mainland and Jeju Island to enhance the stable power supply of Jeju power system. However, as the penetration of RE expands, the risk of transmission line (TL) overload increases, affecting both the mainland and Jeju, potentially leading to regional conflicts based on the operation point of MIDC. To mitigate this issue, this study proposes a methodology for determining the optimal operating point of MIDC to alleviate TL overloads and mitigate the possible curtailment of RE. The impact of the operating point of MIDC and the output of RE on TL overloads is determined through a sensitivity analysis using the power transfer distribution factor. We then propose a method to determine the steady-state optimal operating point of MIDC through linear programming-based optimization for the three optimization objectives. The proposed strategy is validated through case studies of a real Korean power system using PSS/E and MATLAB.