Modelling Aspects of Flexible Multi-Energy Microgrids

The paper presents a corrective receding horizon mixed integer linear programming (MILP) model of multi-energy microgrid (MEM). The operational behavior of local, aggregated generating units, renewable energy sources and customers is investigated through different modelling assumptions and multiple MEM system configurations/layouts. The results clearly show how operational points of multi-energy units, also of the MEM as a single entity, depend on modelling assumptions, in particular, those of converting device efficiencies. These approximations, often used in MEM planning models or matrix Energy Hub concepts, have negligible impact when it comes to long term analyses. However they result in significantly different flexibility indicators in short term operational time frame when compared to the more accurate models. This paper elaborates how these assumptions affect MEM behavior in market driven environment and demonstrates MEM capability to respond to intra-day disturbances caused by variability and uncertainty inherent to the production of the renewable energy sources (RES).