Energy Management System for Smart Hybrid AC/DC Microgrids in Remote Communities

Abstract

This article proposes a new energy management system (EMS) for hybrid AC/DC microgrids (MGs) in remote communities. The major goal of the proposed EMS is to minimize the daily operational costs while supplying sufficient clean water to the remote community, meeting customers’ preferences, and maintaining the technical operational limits of the MG. To achieve this goal, the proposed EMS performs real-time supervisory control on all local controllers of all system assets in both generation and demand sides. On the generation side, distributed renewable and nonrenewable generation units are integrated into the system. Renewable sources of energy are controlled through a maximum power point tracking algorithm for increased efficiency, while nonrenewable DG units are controlled through droop parameters to satisfy the demand. On the demand side, optimal operational schedules for residential appliances and water desalination units are developed to satisfy customers’ requirements and achieve minimum operating costs. Moreover, the EMS controls the AC/DC interlinking converters (ICs) allowing bidirectional flow of power to and from both AC and DC sections of the MG. For practical real-time operation, the proposed EMS utilizes an adaptive rolling-time horizon when responding to changes/disturbances in the system or in user inputs. The assets scheduling problem is modeled as a mixed integer nonlinear programing. Simulation studies were conducted on a hybrid AC/DC MG to demonstrate the effectiveness of the proposed microgrid EMS.