  We study Electric Vehicle (EV) charging from a scheduling perspective, aiming
to minimize delays while respecting the grid constraints. A network of parking
lots is considered, each with a given number of charging stations for electric
vehicles. Some of the parking lots have a roof with solar panels. The demand
that can be served at each parking lot is limited by the capacity of the cables
connecting them to the grid. We assume that EVs arrive at the parking lots
according to a known distribution. Upon arrival, we learn the desired departure
time, the amount of electrical energy it needs to charge its battery, and the
range of rates that it can be charged at. Vehicle arrival patterns, connection
times, and charging volume are based on data collected in the city of Utrecht.
The departure time of an EV is delayed if it has not finished charging in time
for its desired departure. We aim to minimize the total delay. We present a
novel approach, based on an online variant of well-known schedule generation
schemes. We extend these schemes and include them in a destroy-and-repair
heuristic. This resulted in several scheduling strategies. We show their
effectiveness using a discrete event simulation. With this, we show that
applying scheduling approaches increases the amount of EVs that can be charged
at a site and reduces the average delay. Furthermore, we argue the importance
of considering aspects of the grid layout in electricity networks and show the
benefits of using flexible charging rates.
