Vehicle-to-grid power system services with electric and plug-in vehicles based on flexibility in unidirectional charging

Abstract

With proper power scheduling and dynamic pricing, a unidirectional charger can provide benefits and regulation services to the electricity grid, at a level approaching that of bidirectional charging. Power scheduling and schedule flexibility of electric and plug-in hybrid vehicles are addressed. The use of electric vehicles (EVs) as flexibility resources and associated unidirectional vehicle-to-grid benefits are investigated. Power can be scheduled with the EV charger in control of charging or via control by a utility or an aggregator. Charging cost functions suitable for charger- and utility-controlled power scheduling are presented. Ancillary service levels possible with unidirectional vehicle-to-grid are quantified using sample charging scenarios from published data. Impacts of various power schedules and vehicle participation as a flexibility resource on electricity locational prices are evaluated. These include benefits to both owners and load-serving entities. Frequency regulation is considered in the context of unidirectional charging.

Keywords

• demand response
• electric vehicles
• plug-in hybrids
• unidirectional battery charging
• utility dynamic price control
• vehicle-to-grid