Recoverable Service Shortfall-Driven Dispatch for Fixed-Mobile Charging Coordination: Exponential Deadline-Viability Flow on Real Transaction Event Streams

Public charging sessions may terminate prematurely because of charger failures or system anomalies, creating service shortfalls that remain recoverable only within a limited response window. This study introduces recoverable service shortfall (RSS), which converts abnormal charging sessions into actionable mobile-recovery tasks by combining a normal-delivery reference, termination cause, location, and remaining service lifetime. Building on this representation, we propose exponential deadline-viability flow (EDVF), which compares cumulative deadline demand with reachable mobile-service capacity and optimizes irreversible loss, early recovery, and movement in strict lexicographic order. The resulting framework supports scalable optimization across network sizes. Over 153 consecutive Jiaxing evaluation days, EDVF achieves 93.82% Coverage and 74.56 kWh/day Unrecovered RSS while accounting for task lifetime, spatiotemporal reachability, and movement constraints; relative to Myopic dispatch, it reduces Unrecovered RSS by 52.27 kWh/day and increases Coverage by 5.08 percentage points. Binary-gating and UrbanEV experiments provide additional robustness evidence under alternative task definitions, real inter-station distances, finite onboard energy, and travel-speed stress. The study reframes mobile charging from flexible capacity supplementation to a dispatchable service-restoration resource, providing a unified basis for expiry-priority service, cross-station relocation, and scalable resource deployment, with broader relevance to dynamic service systems involving expiring tasks and mobile resources.