Real-Time Charging Navigation Strategy for Expressway Electric Vehicles Considering Secondary Road Network， Regional Distribution Network and Fast Charging Station

[Objective] With the increasing continuous increase in electric vehicle penetration， the mismatch between charging resources and demand on expressways during peak travel periods is becoming increasingly prominent. To address this issue， this paper proposes a real-time charging navigation strategy for the entire charging process on expressways， considering secondary roads， regional distribution networks， and fast-charging stations within the secondary road network. [Methods] First， the expressway network considering secondary road networks， charging behavior of drivers， and the secondary distribution network are modeled based on the physical characteristics of the expressway network. Then， the multi-dimensional factors influencing users’ charging navigation decisions are converted into a multi-level road comprehensive impedance based on individual preferences， establishing a personalized dynamic road resistance （PDRR） model. Finally， through a two-stage real-time charging guidance， the navigation scheme is optimized with the goal of enhancing users' overall charging experience on the expressway network. In the first stage， the fast-charging station with the lowest comprehensive road resistance is preliminary selected based on real-time network information. In the second stage， an improved Floyd-Warshall algorithm is used to identify the route with the lowest weight in the PDRR model in real time and update it accordingly. Both stages incorporate individual preferences and real-time traffic information affecting various key factors of the user charging experience. [Results] Simulation results based on a real multi-level road network show that， compared with the strategy considering only the pure expressway road network， incorporating the secondary "road-network-station" factors reduces the average charging time of each charging station during peak hours by 53.97%， and increases the overall matching degree between the guidance scheme and user demand by 1.96%. [Conclusions] The proposed real-time charging navigation strategy can effectively reduce the overall charging cost， alleviate charging congestion on the expressway network during peak periods， and significantly improve the operational economy and reliability of fast charging stations.