| Electric vehicles as an important means to alleviate the global shortage of fossil fuels and environmental pollution pressure have been supported by governments of all countries.However,slow charging speed,short mileage and other issues has gradually become a bottleneck in the promotion of electric vehicles,but the safe,flexible and efficient wireless charging technology provides a breakthrough for the large-scale application of electric vehicles.The safety and stability of the power grid and the economic operation will be affected by a large number of charging load in the future.The research on the dynamic and static load characteristics and influence of the electric vehicle will be helpful to the scheduling of the vehicle in the wireless charging mode and coordinate with wind and light power generation in the new grid structure,such as micro-grid.Thus,the safety,stability and economy of power network operation can be ensured while increasing the utilization rate of renewable energy.On the basis of building a system model of wind-solar hybrid micro-grid system with wireless charging of electric vehicles,the related data of wireless charging load calculation is analyzed,and a load calculation model based on traffic flow and parking rate is established.Compared with the wired charging,the load characteristics of wireless charging are studied by using Monte Carlo method and found that DWPT mode of wireless charging in random state has the ability to improve the characteristics of the wired charging load.In view of this,a multi objective sequential charging strategy based on bootstrap pricing is proposed.This strategy takes the uncertainty of the vehicle charging behavior and the sensitivity of the charging probability to electricity price into account,and analyzes the possibility of enhancing the spatial and temporal transfer of load under the wireless charging mode and the city line load rate limit is combined.QFA is used to solve the problem that the ordered charge can reduce the peak valley difference of the random wireless charging load and the ratio of the voltage limit node and the network loss can be further reduced by increasing the proportion of DWPT reasonably in the area of economic operation of line load rate.However,the orderly charging can only be used as the primary interaction between the mobile energy storage and the power grid in the process of intelligent development of power grid,so its optimization effect is limited;it is also need to optimize the discharge through the coordination with the power grid to realize the comprehensive interaction of V2 G.In light of this,a multi objective cooperative scheduling strategy is proposed for vehicle mounted energy storage system in micro-grid environment.It combines the orderly charging and discharging of electric vehicles and cooperates with fixed energy storage battery in power grid under the energy management strategy for micro-grid.According to the inherent characteristics of different energy storage devices,the charging and discharging operation is carried out,and the multi objective optimization is realized by means of electricity price guidance and line load rate limitation.Finally,the results of Monte Carlo method and QFA simulation show that the proposed strategy can realize peak load shifting of the total load,improve the utilization of renewable energy and mobile energy storage,reduce the cost of micro electricity online shopping,avoid node voltage over-limit and reduce power loss,achieve the improvement of voltage quality and the smoothness of load fluctuation. |
PDF Full Text Request