Authors: Marina González Vayá; Göran Andersson
Addresses: Power System Laboratory, ETH Zurich, Zurich 8092, Switzerland ' Power System Laboratory, ETH Zurich, Zurich 8092, Switzerland
Abstract: We address the optimal bidding problem of an aggregator that manages the charging of a group of plug-in electric vehicles. The aggregator purchases energy in the day-ahead market, and offers capacity in the frequency regulation market. The charging flexibility of the fleet is expressed as a set of time-varying power and energy constraints. The impact of the aggregator's demand on day-ahead market prices is endogenously modelled by formulating the problem as a bilevel problem: The upper level represents the aggregator's cost minimisation, and the lower level represents the market clearing. We explore several settings of the regulation market, analysing the impact of restrictions that may apply on the capacity offers (e.g., symmetric bids). Moreover, we compare the options of providing regulation with unidirectional charging, and with vehicle-to-grid (V2G). We test the proposed method in a case study for Switzerland, with historical day-ahead and regulation market data, and realistic driving patterns.
Keywords: electric vehicles; optimal bidding; electric vehicle aggregators; day-ahead markets; regulation markets; smart charging; demand side management; ancillary services; frequency regulation; strategic bidding; bilevel optimisation; MPEC; mathematical programming; equilibrium constraints; market prices; modelling; unidirectional charging; vehicle-to-grid; V2G; case study; Switzerland; driving patterns.
International Journal of Electric and Hybrid Vehicles, 2015 Vol.7 No.3, pp.209 - 232
Received: 30 Mar 2015
Accepted: 18 Apr 2015
Published online: 04 Sep 2015 *