Research on the Siting of Mother Stations for Dual-Purpose Mobile Charging Robots on Highways

To address the growing prominence of emergency charging rescue demands for electric vehicles on highways, as well as the issues of insufficient coverage from traditional fixed charging piles and inadequate emergency service capabilities, this paper proposes a methodology based on a System Three-Stage Dynamic Location-Allocation Problem (STSDLAP) for a dual-purpose (routine and emergency) mobile charging robot mother station system. First, Monte Carlo simulation is employed to predict the spatiotemporal distribution of both routine and emergency charging demands. Second, service capacity is evaluated based on non-preemptive priority M/M/C queuing theory to quantify waiting times and system load rates. Finally, an optimization model aiming to minimize cost and maximize coverage, while incorporating constraints on waiting time and load rate, is constructed and solved using the NSGA-II algorithm. Empirical results demonstrate that this solution can achieve emergency response within 30 minutes and meet over 95% of total charging demand on a 1000-kilometer highway section. Compared with traditional fixed charging pile solutions, it not only ensures daily service provision but also significantly enhances emergency handling efficiency. This study provides a reference for the flexible deployment of highway charging infrastructure and cost-effective emergency management.