A Hierarchical Game Theoretical Approach for Energy Management of Electric Vehicles and Charging Stations in Smart Grids

Abstract

By the proliferation of electric vehicles (EVs) in power systems, it is needed to manage their demand energy within a regulated market framework. From the market perspective, integration of different market players, such as the energy producers, aggregators, and loads, could complicate the system operation and management. Therefore, an appropriate model of the market that shows the exact behavior of the system components is needed. In this paper, a new tri-level game theoretical approach for energy management of EVs and EV charging stations (EVCSs) as independent decision makers for their energy scenarios is proposed. To make it practical for a real power system, the system operator is also included in the proposed method as a master decision maker. Therefore, EVs’ and EVCSs’ objectives are to maximize their financial profits, while the system operator indirectly controls their energy scenarios in order to fulfill the system’s technical constraints. To do so, at the highest level of the proposed method, technical goals of the system, which are related to the system operational condition, will be followed as the objective criteria. At the second level of the designed model, the EVCSs financial objectives are optimized. In the third level of the proposed method, it is tried to minimize the EVs’ cost function. The method is tested on an IEEE 9-bus standard system, and the results show a superior performance of the proposed energy management system (EMS) compared with the conventional EMS methods in terms of technical and financial objectives. In this way, it is shown that in the case of considering only one aspect of the system, either financial or technical, the other aspects of the system may not be satisfied. Hence, it is essential to consider both the financial and technical aspects of the system simultaneously, in order to operate the system optimally and securely.