  A battery swapping and charging station (BSCS) is an energy refueling
station, where i) electric vehicles (EVs) with depleted batteries (DBs) can
swap their DBs for fully-charged ones, and ii) the swapped DBs are then charged
until they are fully-charged. Successful deployment of a BSCS system
necessitates a careful planning of swapping- and charging-related
infrastructures, and thus a comprehensive performance evaluation of the BSCS is
becoming crucial. This paper studies such a performance evaluation problem with
a novel mixed queueing network (MQN) model and validates this model with
extensive numerical simulation. We adopt the EVs' blocking probability as our
quality-of-service measure and focus on studying the impact of the key
parameters of the BSCS (e.g., the numbers of parking spaces, swapping islands,
chargers, and batteries) on the blocking probability. We prove a necessary and
sufficient condition for showing the ergodicity of the MQN when the number of
batteries approaches infinity, and further prove that the blocking probability
has two different types of asymptotic behaviors. Meanwhile, for each type of
asymptotic behavior, we analytically derive the asymptotic lower bound of the
blocking probability.
