  Electric vehicles (EVs) have enjoyed increasing adoption because of the
global concerns about the petroleum dependence and greenhouse gas emissions.
However, their limited driving range fosters the occurrence of charging
requests deriving from EV drivers in urban road networks, which have
significant uncertain characteristic from time dimension in the real-world
situation. To tackle the challenge brought by the dynamic charging requests,
this study is devoted to proposing optimal strategies to provide guidance for
EV charging. The time-varying characteristic of road network is further
involved in the problem formulation. Based on the charging request information,
we propose two charging guidance strategies from different perspectives. One of
the strategies considers the travel demands of EV drivers and uses the driving
distance as the optimization criterion. In contrast, the other strategy focuses
on the impacts of EV number on the charging station operation and service
satisfaction. The reachable charging stations with minimum vehicle number are
selected as the optimal ones. More importantly, both the strategies have the
ability to ensure the reachability of selected charging stations in a
time-varying road network. In addition, we conduct simulation examples to
investigate the performance of the proposed charging guidance strategies.
Besides, the insights and recommendations on application scenarios of the
strategies are introduced according to the simulation results under various
parameter scenarios.
