Balancing traffic and charging efficiency for EVs in freeway bottlenecks: Charging (Low-SOC) or fast passage (High-SOC)

Congestion frequently occurs in freeway bottleneck zones. Although various control schemes have been proposed to mitigate this issue, congestion remains challenging to eliminate completely. In recent years, with the continuous growth of electric vehicle (EV) populations, range anxiety and charging inconvenience have become increasingly prominent, particularly within freeway bottleneck zones. Due to speed fluctuations and complex traffic flow variations in these areas, intensified congestion prolongs EV dwell times, further exacerbating range anxiety. To address this challenge, this paper proposes an innovative solution integrating dynamic wireless charging, variable speed limit (VSL) control, and lane-changing strategies. By capitalizing on the congestion characteristics inherent to bottleneck zones, this solution aims to achieve an optimal equilibrium between traffic efficiency and charging efficiency. Specifically, we propose a Dynamically Predictive Variable Speed Limit (DPVSL) control strategy. This strategy dynamically adjusts speed limits by predicting congestion in real-time within bottleneck zones featuring lane drops, thereby optimizing both Total Travel Time (TTT) and Total Net Energy Replenishment (TER) while accommodating the needs of EVs at varying SOC levels. Numerical experimental results demonstrate that, compared to existing control strategies, the DPVSL strategy achieves an optimal balance between traffic efficiency and charging efficiency(enhancing traffic efficiency by 10.79 % and increasing TER by 104.64 kWh). Under this strategy: Low-SOC EVs gain more net charging energy, albeit with slightly increased travel time. High-SOC EVs experience shorter traversal times through bottlenecks but receive relatively less net charging energy. The results further validate the effectiveness of this strategy, demonstrating its ability to not only reduce user travel costs but also significantly alleviate EV range anxiety.