  Uncoordinated charging of large-scale electric vehicles (EVs) will have a
negative impact on the secure and economic operation of the power system,
especially at the distribution level. Given that the charging load of EVs can
be controlled to some extent, research on the optimal charging control of EVs
has been extensively carried out. In this paper, two possible smart charging
scenarios in China are studied: centralized optimal charging operated by an
aggregator and decentralized optimal charging managed by individual users.
Under the assumption that the aggregators and individual users only concern the
economic benefits, new load peaks will arise under time of use (TOU) pricing
which is extensively employed in China. To solve this problem, a simple
incentive mechanism is proposed for centralized optimal charging while a
rolling-update pricing scheme is devised for decentralized optimal charging.
The original optimal charging models are modified to account for the developed
schemes. Simulated tests corroborate the efficacy of optimal scheduling for
charging EVs in various scenarios.
