Joint Generation, Transmission and Energy Storage Systems Expansion Planning in Multi-area Power Systems Considering Detailed Modeling of Tie lines

The interconnection of sub-regions through tie lines can improve the overall economy of the system and provide a broad space for renewable energy consumption, such as wind power. However, at present, no detailed models exist for tie lines in the planning of multi-area power systems. In this paper, a novel multi-area and multi-objective model for the generation, transmission, and battery energy storage systems expansion planning is proposed in a central planning method that considers uncertainties of wind power and load. Tie lines among different subareas are used as support power sources, and detailed tie-line expansion planning models that consider the power flow direction, degree of power flow fluctuation, and number of power flow direction reversal in the tie line are presented to make the model more realistic. Besides, short-term operation problems (i.e., unit commitment) are incorporated in the long term planning issues to improve the adaptability of planning schemes. Linearized procedure for the different tie-line operation modes is implemented in order to improve the efficiency of the presented model. The proposed model is finally transformed into a mixedinteger linear programming formulation. The modified IEEE RTS-24 bus system is conducted to evaluate the practicality and effectiveness of the proposed method.