Coordinated planning of transmission expansion and coal‐fired power plants flexibility retrofits to accommodate the high penetration of wind power

As one of the promising renewable energy technologies, wind power generation has developed rapidly over the last decade. However, the rapid growth of wind power resulted in significant wind curtailment due to transmission congestion and lack of flexible resources. Although energy storage is the most efficient way to increase the flexibility of the power system, large capacities of cost-effective energy storage are not yet available today. Considering that coal-fired power plants are still the dominant suppliers of electricity in many countries, it has a great potential to increase large amounts of flexibility by retrofitting the existing coal-fired power plants. In this study, the coordinated planning model for transmission expansion and coal-fired power plants flexibility retrofits is proposed to accommodate high penetration of wind power. Robust optimisation is employed to handle the uncertainties of peak load demand and wind power capacity, and the robust planning model is solved by nested column-and-constraint generation method. The validity of the proposed planning model is demonstrated using the modified IEEE 24-bus test system and modified IEEE 118-bus test system.