Congestion Risk Alleviation in Modern Distribution Systems Using Electric Vehicles as Mobile Energy Storage Devices

In the modern distribution systems (DSs), one of the severe challenges that the distribution system operators (DSOs) have is the risk of congestion in a day-ahead operation. Electric vehicles (EVs), as mobile energy storage assets, can travel around the system and help the DSO to minimize the risk of congestion. In this paper, a two-level management framework is proposed to mitigate the risk of congestion in a day-ahead operation. The DSO uses a subsidy mechanism to compensate for the EVs rescheduling cost in a low-level risk (LLR) of congestion. The DSO also uses a dynamic tariff (DT) method to motivate EVs to plug in the area without congestion risk if there is a high-level risk (HLR) of congestion in the system. The modified IEEE 13-bus unbalanced distribution system is used as a case study. It is inferred from the simulation results that the collaboration among DSO and the EV aggregators (EVAGs) can significantly reduce the congestion risk. The proposed framework can take advantage of EVs' mobility and motivate them to use cheaper charging places. It gives the possibility to manage the congestion in a modern distribution system with numerous EVs.