Optimal operation of microgrid with consideration of V2G's uncertainty

The aggregation of the remaining battery capacity of electric vehicles (EVs) can be used as distributed energy storage to participate in the microgrid optimisation through vehicle-to-grid (V2G) technology. However, the reliability of this service to be delivered is affected by the uncertainty of EVs' behaviour. The un-reliable service will bring risks in the operation of microgrid when EVs' V2G electricity is regarded as an important flexibility resource. This paper, first proposes an analytical method to quantify the reliability of EV aggregation's (EVA's) V2G electricity based on the analysis of historical charging data and compound Poisson process. Based on this model, electric vehicles aggregators can evaluate the V2G bid quantity for any time slot on day t+1 according to the reliability requirements. Secondly, an optimal operation model of microgrid with consideration of V2G's reliability is considered. Finally, a test system with photovoltaics (PVs) and EVA on top of the original IEEE 33-node system is used to verify the effectiveness of the proposed model. The results show that with the proposed reliability evaluation method of V2G electricity, the optimal operation of the microgrid can be reached with appropriate evaluation of the capability of the EVA. 1 Based on the compound Poisson process, a model for calculating the bid quantity and its reliability for vehicle-to-grid (V2G) when electric vehicles aggregator (EVA) participates in the day-ahead ancillary service is proposed.2 A method to characterize the probability distribution of the available V2G electricity for the EV users at any given time is proposed.3 A method based on historical charging data from private EV users to classify and estimate the available V2G electricity at any given time is proposed.4 The factors that influence the reliability of day-ahead V2G electricity for private EVA are analysed.5 Based on the cases of sudden PV decrease and load increase, a model for the participation of EVA in microgrid optimisation is established.image