Multi-objective long term optimal dispatch of distributed energy resources in micro-grids

The amount of distributed generators in power distribution systems is evermore increasing, and the potential benefits and drawbacks are becoming clearer. The optimal management of Distributed Energy Resources (DER) in microgrids is essential to guarantee their best exploitation. Optimal operation allows to maximize their benefits, such as reduction of network energy losses, reduction of carbon emissions and to minimize the negative effects of a strong DER penetration, such as the increase of infrastructural investment and operational costs. Hence, DER management is a multi-objective problem in which many objectives of interest, often conflicting, need to be optimized simultaneously. In this paper, the problem of the 24-hours unit commitment of distributed generators supplying a LV micro-grid connected to the main grid is addressed. The model developed considers the management of storage systems concentrated at some of the grid buses. The considered objectives are: to minimize generators annual cost, carbon emissions of the overall system and line losses. The unknowns are: the hourly power production of DER and the hourly storage unit level. The results show that the multi-objective approach based on non domination provides a wide range of alternatives and allows a strong optimization of the considered objectives.