Research On Dynamic Economic Dispatch Considering The Strategies Of Electric Vehicle Charging And Discharging

In recent years,the evolution and development of electric vehicles have provided a solution to the ever-deteriorating environmental problem.However,a large scale electric vehicle which connects to the power grid will pose an obvious challenge to the stability of the grid.Therefore,there is a need to regularly control the charging and discharging load of the vehicles to make sure the power system operates safely.Hence,the aim of the thesis is to build a model of the vehicle charging and discharging,optimise the charging and discharging load and develop a strategy of the dynamic economic dispatch.The first contribution of this thesis is to present various electric vehicle projects on the driving and charging behavior in most European countries and in America,which include the average distance travelled per day and trip,energy consumption per kilometre,return of the last journey of the day,charging location,charging frequency,state of charge and so forth.Secondly,three methodologies for the EV to interact with the grid,namely dumb charging,smart charging,and vehicle-to-grid,are introduced in this thesis to illustrate the impact on the power system.After this,the thesis presents a framework of the EV charging and discharging.In this framework,not only a dynamic charging price,which aims to capture the interaction between the charging load,is developed for the optimization of the charging load one by one,but also the availability of EV for grid services,or the parking time,which functions as a benchmark of the charging times in one single day,is considered.Thirdly,a dynamic economic dispatch model is developed to evaluate the likely operating regimes of thermal power plants after calculating the EV charging and discharging load.Security constraints for power plant operating constraints,such as power output limits and ramp rates,ensure the operational feasibility of the dispatch schedules.In addition,to solve this nonlinear,nonconvex,multi-objective model,an improved pattern search algorithm is developed for the exactness and time-consuming calculation of the optimal solution.Finally,numerical cases on the IEEE 39 bus feeder demonstrate the effectiveness of the model.This thesis is expected to provide useful insights for the regulation of the electric vehicle and the operation of the power system.