Optimal Planning of HVDC Converter Stations for AC-DC Mixed Power Grid with High Penetration of Renewable Energy

High voltage direct current (HVDC) transmission is the best option to deliver generated power especially from renewable energy, e.g. wind and solar farms that are far away from the load center. However, one of the key challenges in designing the HVDC integrated into the receiving end AC power grid is to optimize the location for HVDC converter stations of different capacities. Optimizing the location of HVDC converter stations has significant impact on the system short circuit capacity, voltage stability and multi-infeed short circuit ratio (MISCR). The optimal sizing and placement problem of HVDC converter stations is formulated as a complex multi-criteria decision making which considers economical efficiency, power system stability, and the power flow distribution of the grid. A case study based on the IEEE 39-bus system with high penetration of renewable energy is performed to evaluate the effectiveness of the proposed method. The ranking of the optimal locations is done by combining grey relational theory and technique for order preference by similarity to ideal solution (TOPSIS). The results demonstrate that the proposed method can locate optimal sites for HVDC stations at different capacities.