Optimal hierarchical energy management scheme for networked microgrids considering uncertainties, demand response, and adjustable power

Abstract

In this study, a novel strategy for transactive energy in the networked microgrids (MGs) is presented. This strategy consists of three stages: local optimisation, global optimisation, and re-local optimisation. In the local optimisation, the daily cost of each MG is minimised by local energy management systems (EMSs). The results of the local optimisation are sent to the central energy management system (CEMS), and global optimisation is performed by CEMS. Finally, the primary scheduling of MGs is modified in re-local optimisation. The adjustable power concept is introduced to provide power exchange among MGs and external units. Various uncertainties, such as loads, renewable generations, and market prices are deliberated to the model. To do so, the worst condition of forecasted values of renewable generations and load consumptions are considered to assign a safety margin. Besides, the uncertainty of market prices is implemented by using the variance matrix based on forecasted and real values of market prices in D days in advance. To evaluate the efficiency of the proposed model, it is tested on a standard case study. The simulation results show that the cost of MGs in the grid-connected mode is improved effectively.