Research On Community-Level Electric Vehicle Charging Coordination Strategy Based On The Enhanced Hysteresis Model

Nowadays,climate and energy issues are serious challenges faced by the world.Electric Vehicle(EV),as an important resource to promote energy transition,is rapidly developing and gradually replacing fuel vehicles with the support of policies in various countries and regions.However,the uncontrolled charging behavior of large-scale EVs,especially in communities,can threaten the security of distribution systems,for the charge time of EVs in communities coincides with the peak of residential electricity consumption.Coordination of the EV charging behavior in communities to alleviate the pressure of power systems and enhance flexibility has become a focus.To address the above issues,this thesis investigates the EV charging coordination in communities based on the enhanced hysteresis model,aiming to reduce the risk of power system operation and improve the economic benefits of EV owners and EV Aggregators(EVAs)by managing the charging and discharging behavior of community EVs.Firstly,the enhanced hysteresis model is established based on the cost optimality of individual EV owners.With the time-of-use tariff,an optimization model is developed with the objective of minimizing the charging cost of EV,and the corresponding charging/discharging durations are obtained for each tariff period;based on the optimal charging/discharging durations,the nominal charging profile is constructed,and the conventional hysteresis model is enhanced considering V2 G.Case studies verifies the superiority of the proposed enhanced hysteresis model in reducing charging cost and smoothing load profile.Secondly,the priority method for EVs is established based on the characteristics of the enhanced hysteresis model(including dead zone and state switching mechanism),and combined with the enhanced hysteresis model to form a real-time control strategy.The priority index is constructed considering the SOC,state switching frequency and charging time margin;and then the real-time control strategy is developed according to the real-time scheduling requirements.Case studies verify the dispatch flexibility of the proposed priority method and real-time control strategy,and sensitivity analysis is performed.Finally,the thesis has developed a multi-time-scale coordination strategy based on the enhanced hysteresis model.The day-ahead coordination strategy is developed with the objectives of optimal charging cost,load fluctuation and peak-to-valley difference in the region.Then the rolling intra-day coordination strategy is established to minimize the deviation from the day-ahead schedule,and the communities are guided to play a cooperative game to further reduce the economic loss caused by the deviation between the day-intra schedule and the day-ahead schedule.Then,with the intra-day schedule as the target power,and EVA achieves tracking of this target with the real-time control strategy based on the enhanced hysteresis model.Case studies verify the economic promotion and the reasonable economic allocation of the proposed cooperative game strategy.It is also confirmed that the proposed multi-time scale coordination strategy can effectively guide EV owners’ charging behavior.In summary,the proposed methods can realize the EVs charging coordination in communities,promote the economic benefits of EV owners and EV aggregators,and exploit the flexibility of EVs to ensure the security and stability of the power system.