Research On Optimal Operation For Distribution Network With Electric Vehicle

With the rapid development of the electric vehicle industry,more and more electric vehicles are connected to the power grid as an emerging means of transportation Electric vehicles are connected to the distribution network for charging.On the one hand,it will bring new power loads to the grid and bring new challenges to the operation of the grid,on the other hand,as a kind of distributed generation,electric vehicle energy storage battery can be used to optimize the charging and discharging scheduling of electric vehicle energy storage battery by the power grid,which can absorb the excess wind and light energy during the load valley,and discharge the power grid during the load peak to reduce the power supply pressure of the power plant.At the same time,the voltage drop caused by insufficient power supply is reduced to improve the economy and safety of distribution network operation.Firstly,this paper carries out simulation modeling on the operation mode of electric vehicle,and establishes the mathematical model of electric vehicle random charging behavior.Aiming at the randomness of output and conventional load of renewable energy including photovoltaic and wind turbine,the interval optimization method is adopted to deal with the uncertainty of random variables in the operation model of distribution network.Model based on the V2G operation model and the interval optimization method,established by economic considerations of V2G economic optimization model.The simulation results prove that reasonable arrangement of charging and discharging of electric vehicles and the addition of V2G to power grid operation can effectively improve the economy of power grid operation.Secondly,in the second chapter of this article,considering the limitations of traditional interval optimization methods in dealing with large-scale distribution network operation,an improved interval optimization algorithm is proposed.The model of electric vehicle participating in voltage regulation and optimal operation of distribution network is established.The model extends the classification of electric vehicles and carries out simulation modeling of electric buses.The influence of random access charging of EV on the voltage of distribution network is analyzed.The model compares the effect of EV participating in voltage regulation of distribution network under random charging and discharging mode and V2G operation model.The simulation results show that scheduling the charging and discharging behavior of electric vehicles with the voltage deviation of distribution network as the target can effectively reduce the overall voltage drop of the grid during the peak load period and enhance the stability of the grid operation.Finally,this paper establishes the model of multi-time-scale EV participating in the optimal operation of distribution network.The forecast data of day-ahead optimization are based on the historical operation data of distribution network,and there is a big deviation in the actual operation process.Based on the interval of optimization results obtained by day-ahead optimization,the multi-time-scale operation model in this paper runs on day-ahead optimization scheme in the real-time operation process,and gives feedback correction to the day-ahead optimization scheme.Based on different optimization objectives,the problem of two-stage optimization operation is analyzed on different time scales.The simulation results show that the two-stage optimization problem can effectively improve the accuracy of day-ahead optimization and real-time optimization,and it has better optimization effect.