Cooperative energy management system for networked microgrids

Abstract

This paper proposes a hybrid Energy Management Systems (EMS) architecture based on canonical coalition games for cooperative power exchange management of networked microgrids, interconnected with the main grid through a macro station. A central EMS and local EMSs perform three main processes: scheduling process, monitoring and rescheduling process, and benefits distribution process. A value function verifying the superadditivity property, which guarantees the grand coalition is the best coalition structure, and a computationally efficient non-linear scheduling model, which allows obtaining the power exchange strategy that minimizes transmission and transformation power losses, are defined. The scheduling process uses the scheduling model to generate a cooperative schedule for a rolling horizon. In order to enhance the performance of networked microgrids, the monitoring process uses efficiency thresholds for monitoring the schedule execution to identify schedule disruptions. For preserving the private information of microgrids, each local EMS only informs the central EMS of their state profiles, which specifies its power surplus or deficit for each time period of the scheduling horizon. The benefit-distribution process uses a Core-based model for distributing saved power loss obtained as a result of the power exchanged during the schedule execution. By comparing the proposed approach with a coalition formation game-based algorithm recently reported in the literature, it is concluded that the problem of power exchange management of networked microgrids should be modeled as a canonical coalition game and not as a coalition formation game. Results obtained from a prototype testing of the proposed EMS are presented.