The ever continued growth and development of distributed generation(DG)in the electrical grid system led to the increasing expansion of microgrids.Microgrids contains distributed power generation units,energy storage devices,and controllable loads with the capability to operate in both grid-connected and island modes.Microgrids economic operation is achieved through an energy management system which optimally schedules distributed generations and storage devices and continuously balances supply and demand.In this paper,a formulation of optimal unit commitment and dispatch scheduling of DGs in a grid-connected microgrid is presented.Mixed integer linear programming(MILP)is used to implement the optimal resource scheduling model.The objective is to minimize the overall operating cost of the system by optimally utilizing an energy storage device and a combined heat and power(CHP)generation unit by using load and renewable energy generation prediction.Operational constraints such as generation limits of DGs,battery charging/discharging limits and state of charge(SOC)limits are to be satisfied during all intervals of operation.Simulation results indicate that the operational cost of the system is effectively reduced through an optimal scheduling of an energy storage system and a CHP unit using the proposed strategy. |