Power transmission expansion planning considering large bulk power injection

The developments of UHVDC & UHVAC systems in China have imposed new challenges on power system planning and operation. These include the impacts on network structure expansion, generation output schedule, reserve capacity arrangement at bulk power receiving end, exchange power on tie lines and power support mode under new conditions, etc. A multi-objective power transmission expansion planning model is established with consideration of both investment and reliability requirements under large bulk power injection background. To guarantee power supply of receiving end power system when bulk power transmission line faults, maximum power transfer capability under N and (N-1) security should be obtained with least investment. Regional generation reserve capacity constraints of receiving end power system should be met in planning process. The plant growth simulation algorithm is adopted to solve this integer planning problem. The typical test system is analyzed to show the validity of the proposed model and methodology.