A collaborative hierarchal optimization framework for sustainable multi-microgrid systems considering generation and demand-side flexibilities

Abstract

This paper proposes a day-ahead stochastic operation planning for hybrid renewable/non-renewable multi-microgrid systems. The proposed model performs a multi-objective tri-stage decision-making framework to optimize the operating cost, generation flexibility, and demand-side flexibility simultaneously. The first stage of the proposed model presents a cooperative game to minimize the total operating cost of the multi-microgrid system. In this stage, microgrids consider the uncertainty of generation and consumption and share their local resources. This cooperation enhances the efficiency of energy scheduling and creates an overall gain. The Shapley value is used to consider the contribution of microgrids and define their operating costs. At the second and third stages, the generation and demand-side flexibilities are maximized to enhance the ability of the multi-microgrid system compared to the short-term changes in the system. Two new indexes Average Flexibility of Distributed Generation during Peak Period (AFDGPP) and Average Flexibility of Storage System during Peak Period (AFSSPP) are introduced to evaluate the flexibility of the system in different operating conditions. The proposed model is tested on a standard case study and the simulation results show that the AFDGPP and AFSSPP indexes have been improved by 161.8 kW and 92.32 kW, respectively.