Integration of Meshed Offshore Hvdc Grids In Electricity Markets Under Security Constraints

This paper compares the impact on operating costs and various economic indicators of integrating a meshed offshore HVDC grid into electricity markets under different security approaches. The analysis combines preventive N-1 and corrective security-constrained schemes for hybrid AC/DC systems, enhanced by droop control optimisation and extra corrective wind curtailment. Since these grids will become part of the European electricity market, they are embedded in an advanced hybrid coupling algorithm and compared with a reference case without contingencies on the DC side. The methodology is applied to an extended IEEE 3-area RTS. Results show that operating the offshore HVDC grid under a corrective scheme, while the main AC grid follows a preventive approach, and with no extra corrective wind curtailment needed, provides the most effective trade-off between economy and security in hybrid system operation. This strategy ensures lower wind curtailment, reduced need for redispatch, and lower electricity prices, thereby supporting efficient, sustainable, and secure operation by transmission system operators.