Objective Trade-off in MPC Based Energy Management for Microgrids

Microgrids (MGs) are considered one of the key enabling factors of future electric power systems. Their limited size allows optimal control, as the solution space of optimization problems increases exponentially with the number of assets, if significant model simplifications are not undertaken. Additionally, the capability to disconnect from the main grid and autonomously supply loads can serve to increase the resilience to failures in the main grid and be provided as a service to the Distribution System Operator (DSO). An energy management system (EMS) is responsible to facilitate the optimal use of resources; however, optimality can refer to a multitude of target objectives. This paper builds up on previous research, implementing a Model Predictive Control (MPC) based EMS that is used to show the trade-off between four different objectives in MG operation. The different objective functions are the minimization of operational cost, minimization of the energy exchanged with the main grid, minimization of resistive losses and maximization of potential islanding time (PIT) for a possible future islanding event.