Microgrid expansion through a compressed air assisted wind energy system

In a traditional power distribution system, as the community expands, the system designer plans to upgrade the capacity of transmission line to the load center. However, integrating a distributed energy resource and distributed energy storage could be an alternative to decrease the microgrid's dependence on transmission line. In this paper, a compressed air assisted wind energy conversion system (CA-WECS) is introduced. The CAWECS provides both distributed energy resource and distributed energy storage to the microgrid. A stochastic programming framework is proposed to assist the decision among upgrading the transmission line, integrating the CAWECS or the combination of both. The optimal power capacity, and storage capacity of CA-WECS, as well as the capacity of transmission line to the microgrid are determined by solving the mixed integer linear program. A numerical example is investigated to evaluate the performance of the new system. The comparison result shows that integration of a CA-WECS can largely decrease the demand on the transmission line, thus the capacity of the transmission line is decreased from 1000kW to 750kW for the identical load pattern. The average power flow though point of common coupling is reduced by around 50%. The energy cost of the community is reduced by 18%.