N - 1 Contingency Constrained Transmission Expansion Planning with Offshore Wind Farm Integration

Offshore wind farm (OWF) has been developed rapidly worldwide as one of the promising renewable energy technologies. Transmission expansion and flexibility reformation of thermal power units may be necessary to accommodate wind power and maintain operational security. This paper proposes an optimization approach to jointly optimize the sites of OWF integration, the transmission expansion, and the flexibility reformation of thermal power units. In the planning model, the total investment cost is minimized under the requirements of wind power utilization and N-1 security. The problem is decomposed and solved by an iterative algorithm, which comes down to solving mixed-integer linear programming problems repeatedly with modified constraints. The case study based on the IEEE-30 bus system demonstrates the effectiveness of the proposed method.