Optimization-based operation of island hybrid power systems: a case study in Suðuroy, Faroe Islands

An optimization-based energy management system (EMS) for the island hybrid power system of Suðuroy on the Faroe Islands is proposed in this paper. Next to balancing generation and load, the aim lies in reducing the operational costs while dealing with uncertainties from the intermittent nature of renewables. This is achieved by a two-layer model predictive control (MPC) approach solving a mixed-integer linear programming problem for unit commitment, as well as a non-linear programming optimal power flow problem for economic dispatch. The setpoints are transferred to the local controllers of the distributed energy resources. Simulations of the MPC strategy show that the utilization of renewables is preferred and, thus, decreasing operational costs are obtained while satisfying operational and security requirements. The proposed EMS is further investigated in quasi-stationary simulations using a simplified model of the Suðuroy power system. It can be observed that after changes of power setpoints and besides small deviations from the predicted values, no stability boundaries are violated.