Research On Scheduling Strategies Of Electric Vehicles Participating In Voltage Regulation In Smart Grid

In order to alleviate the problem of energy crisis and environmental pollution,governments are gradually strengthening the research on new energy based transportation.The electric vehicles(EVs)have attracted broad attention around the world and been rapidly developed because of their advantages such as non-pollution,low-noise and simple structure,etc.It has negative effects on the smart grid that EVs randomly plug in the smart grid to charge.The negative effects include overload,grid frequency fluctuation and grid voltage fluctuation,etc.Nevertheless,EVs have long average park time,fast response speed and good flexibility,which makes it possible for them to provide auxiliary services like voltage regulation for the smart grid.So far,it has attracted the attention of scholars all around the world that how to schedule the plug-in EVs to provide voltage regulation service for the smart grid.Although progress has been made tin related research,huge challenges lie ahead and more needs to be down.For example,how to balance the stability of grid voltage,the charging demands of the EV users and the economic interests of the the EV scheduling center,namely aggregator(AGG).Aiming at this problem,this paper proposes a scheduling model based on the economic interests of the AGG and studies the scheduling strategy on EV-based voltage regulation.More details are as follows:Firstly,according to the rationale and basic structure of EV-based voltage regulation combined with the general infrastructure of the smart grid,this paper proposes the topology structure of the scheduling system with plugged-in EVs.An AGG is drawn into the topology structure to act as an agent between the grid operator and the EV users.The AGG need to design the scheduling strategy and send it to all EV users to instruct their operations.Secondly,this paper formulates the economic model of the AGG,the stability model of the grid voltage and the charging demand model of the EV users based on the aforementioned topology structure.Then,this paper formulates the optimal scheduling model of the EV-based voltage regulation based on the economic interests of the AGG and designs an optimal scheduling strategy according to the scheduling model.Thirdly,this paper fully analyzes the randomness of the EV users' behaviors and proposes another optimal scheduling strategy based on analysis results as well as the above optimal scheduling model.Besides,in order to better motivate the EV users to participate in voltage regulation,an incentive reactive power price bidding method is proposed using game theory.On the basis of the aforementioned research,simulation and analysis of the optimal scheduling strategies proposed are performed on MATLAB platform.The simulation results show that the scheduling strategies proposed in this paper can improve the grid voltage,raise the economic interests of the AGG,reduce the cost of the EV users and so on.Besides,the second scheduling strategy is more in line with the actual situations and does better at voltage regulation compared to the first one.