Electric Vehicles Charging System in Apartment Complexes Under the Limited Number of Chargers

초록

The coexistence of growing electric vehicle (EV) populations and legacy parking infrastructure in apartment complexes creates a critical resource constraint, characterized by a severely limited number of available chargers. In this infrastructure-scarce setting, most existing systems rely on uncontrolled charging. Under the conventional fi xed occupancy assumption—where an EV remains connected until its charging goal is met—this approach leads directly to persistent charger overstay and drastically low utilization of the scarce resource. To fundamentally overcome the limitations imposed by this high EV-to-charger ratio, we propose a reservation-based EV charging scheduling framework that incorporates userspecifi ed move-and-park availability. This availability is defi ned by time windows during which users voluntarily move their vehicle between charging and non-charging slots. Integrating such user behavioral fl exibility enables charger rotation, transforming the limited charger into high-throughput shared resources. The scheduling problem is formulated as a mixedinteger nonlinear programming model aimed at minimizing aggregate user dissatisfaction (refl ecting incomplete charging or denied access). Using real-world charging data collected from apartment complexes in Korea, we compared the proposed user-aware scheduling framework against uncontrolled and fi xed-occupancy baselines. Simulations demonstrate that our approach achieves a 67.7% reduction in total user dissatisfaction (from 4.65 to 1.5) compared with the uncontrolled FCFS baseline. The inclusion of proactive user movement is shown to be vital for maintaining high throughput and equitable access. These fi ndings highlight that, under high-demand conditions, at least half of EVs must have access to dedicated chargers to ensure acceptable user satisfaction. Overall, the proposed system establishes a scalable pathway for managing shared EV charging resources in infrastructure-limited urban environments.

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