Optimal management algorithm of microgrid connected to the distribution network considering renewable energy system uncertainties

•This paper presents a new management methodology to find the optimum operation of a grid-connected MG, which is modeled as an optimization approach and aims to minimize total cost.•The uncertainties in renewable energy-based DG units, including wind turbine (WT) and photovoltaic (PV), are also considered in this study.•The optimization problem is formulated, where its objectives include minimization of total operational and planning cost of the microgrid system.•The simulation results demonstrate that the proposed methodology can supply all required electricity and simultaneously optimize power transactions between MG and the main network.