Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology, Ministry of Education (Northeast Electric Power University), Jilin 132012, China

In order to address the urgent need for flexibility resources in transmission networks and tap into the flexibility support potential of distributed resources in distribution networks, firstly, a vehicle-to-grid response model for electric vehicles in the market environment is constructed to analyze the demand response ability of electric vehicles under different charging-discharging modes, which provides the model basis for electric vehicles to participate in power grid dispatch and control in the market environment. Then, taking into account the aggregation effect of distribution network operators on demand-side flexibility resources, a clearing model of energy-flexibility markets with transmission and distribution coordination is proposed considering charging and discharging modes of electric vehicles with the objective to minimize the total cost of purchasing electricity and flexibility resources. Various flexibility resources in transmission and distribution networks are coordinated and controlled to meet the flexibility demand of the transmission network. Finally, the effectiveness of the proposed clearing method of energy-flexibility markets with transmission and distribution coordination is analyzed and verified by the coupling test system with improved IEEE 33-bus transmission network and two IEEE 33-bus distribution networks. The results show that the proposed method can improve the operation economy and flexibility of power systems.