A Framework for Simultaneous Management of Greenhouse Gas Emission and Substation Transformer Congestion via Cooperative Microgrids

Abstract

This paper proposes a cooperative framework among microgrids (MGs) in a distribution power network to systematically manage pollution and substation transformer congestion (PSTC). In the first layer, each MG conducts an optimization individually for the day-ahead unit commitment with the objective of cost minimization. In the second layer, the MGs cooperate with each other to result in an effective PSTC management. The proposed operator in this paper, named microgrids aggregator (MGA), supervises the cooperative mechanism of MGs such that 1) purchased power from the distribution system operator (DSO) is minimized to result in congestion management of substation transformer (ST), 2) reliance on fossil fuels is controlled to prevent excessive CO2 emission, 3) sensitive data of each MG is only shared with MGA and other MG operators will have no access to such information. Finally, in the third layer, DSO receives the modified schedules from MGAs to ensure no technical constraint in the entire system is violated. If such a violation exists, a mandatory load shedding will be implemented by DSO. The effectiveness of the introduced framework is validated on the 33-bus IEEE distribution network modified with diesel-engine distributed generation (DEDG) units, wind turbine DGs (WTDGs), photovoltaic DGs (PVDGs), and electric vehicles (EV) stations.