Study Of The Charging Navigation Of Electric Vehicles Considering The Voltage Endurance Of Urban Distribution System And Its Coordinated Fast Charging Strategy

Electric Vehicle(EV) is a new media of transportation that can effectively reduce the environmental pollution and fossil energy consumption caused by fuel vehicle. EVs and other new energy vehicles will gradually replace traditional fuel vehicles and become an important trend for future development of automotive industry. With the penetration of EVs gradually increases, the charging demand of EV users will also magnifies. Existing researches show that random charging of large numbers of EVs will bring about many negative effects, such as widening peak- valley difference, increasing harmonic currents, exacerbating voltage deviation and so on. In order to mitigate the adverse effects and guarantee the safe and economic operation of the power grid after connection of large-scaled EVs, it is of great necessity to develop a charging navigation strategy and a coordinated charging guide policy that are accessible for EV users and can guarantee reliable operation of the power grid. Taking the requirements above into account, two issues are studied in this thesis, i.e., EV charging navigation and coordinated charging guidance. The main contents are as follows:Current vehicle navigation system does not consider the part of the power grid, thus it is not completely suitable for the navigation of EVs. To address this problem, an EV charging navigation strategy considering the voltage endurance of the distribution system is proposed in this paper. The formation of the EV charging navigation strategy is analyzed from 3 perspectives, i.e., the user side, the power grid side and the traffic side. For the power grid side, a distribution system voltage endurance index of the fast charging station location node is proposed, and the corresponding power adjustment method of fast charging piles is analyzed. For the traffic side, an optimal path planning method based on Dijkstra algorithm is analyzed. The EV charging navigation strategy proposed in this thesis combines the information provided by the power grid side and the traffic side, and it is capable of meeting diverse needs of EV users. With the navigation strategy, EV users can obtain more comprehensive information and receive better charging experience.To address the problem that EV uncoordinated fast charging may lead to a waste of resources, a coordinated fast charging strategy based on the adjustment of charging service fee is proposed in this thesis. The responsive behavior of cost-sensitive EV users is firstly analyzed. Considering the power grid benefit and user satisfaction, the charging service fee of each fast charging station is formulated by using fuzzy planning method and genetic algorithm. Simulation example shows that this charging guide method can effectively improve the charge uniformity of the region and ensure user experience at the same time. Hence, spatially coordinated charging is achieved.