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

Abstract

Renewable energy systems have been introduced into Microgrids (MGs) due to environmental issues and fossil fuel depletion. 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 Distributed Generation (DG) units, including Wind Turbine (WT) and Photovoltaic (PV), are also considered in this study. The balance between total electricity generation and required demand in the system is determined based on the power interchange between the MG and the distribution system. The optimization problem is formulated, where its objectives include minimization of total operational and planning cost of the MG system, improving the voltage profile, and reducing total power losses of the distribution system. The presented methodology is applied on a 13-bus network, and the results are compared under different conditions. The simulation results demonstrate that the proposed methodology can supply all required electricity and simultaneously optimize power transactions between MG and the main network. Furthermore, it is indicated that the optimal power transaction between the main network and MG can reduce the distribution network's total operational cost. Meanwhile, reducing total power losses (i.e., more than 30 %) and improving the studied network's voltage profile results in a grid-connected mode.