Energy Management of Multi-Microgrids in Joint Energy and Ancillary Service Market Considering Uncertainties of Renewables

Abstract

In this study, energy management of grid-connected Multi-Microgrid (MMG) is performed through joint optimization of the energy and ancillary service market. The test system comprises the IEEE 30 bus system as the main grid and the 16-bus system as an MMG. The MMG is comprised of dispatchable and non-dispatchable generation and loads. The non-dispatchable generators are based on renewable energy sources (RES) such as solar and wind. The uncertainty modeling for wind and solar is performed by Weibull and beta probability distribution function. The strategic integration of RES helps MMG deliver both energy and ancillary services to the utility grid. This research aims to reduce the total energy cost while reducing reserve cost by maximizing the use of RES under normal operation and during contingency conditions. It is observed that if MMG is incorporated into the system, then the total generation cost, reserve cost, and power losses are reduced to 0.11 %, 0.325 %, and 1.201 %, respectively, in normal operating conditions. Under contingency, when Generator 5 is out of service and the main grid is operating alone, the total generation cost increased significantly from 22118.92 $ day-1 to 22435.68 $ day-1 and the real power loss increased from 233.35 MW day-1 to 245.11 MW day-1. However, by interconnecting MMG with the main grid, generation cost and power loss get reduced to 22375.60 $ day-1 and 243.35 MW day-1, respectively. It is analyzed that participation of MMG provides techno-economic benefits during normal operation and contingency conditions.

Keywords

• renewable energy sources
• energy management
• multi-microgrid
• energy market
• ancillary service market