Management of electric vehicle systems with self-interested actors

Overview & Synopsis

Electric Vehicles (EVs), as their penetration increases, are not only challenging the sustainability of the power grid, but also stimulating and promoting its upgrading. Indeed, EVs can actively reinforce the development of the Smart Grid if their charging processes are properly coordinated through two-way communications, possibly benefiting all types of actors. Because grid systems involve a large number of actors with nonaligned objectives, we focus on the economic and incentive aspects, where each actor behaves in its own interest. We indeed believe that the market structure will directly impact the actors' behaviors, and as a result the total benefits that the presence of EVs can earn the society, hence the need for a careful design. The thesis first provides an overview of economic models considering unidirectional energy flows, but also bidirectional energy flows, i.e., with EVs temporarily providing energy to the grid. We describe and compare the main approaches, summarize the requirements on the supporting communication systems, and propose a classification to highlight the most important results and lacks. We propose to use the recharging processes of EVs to provide regulation to the grid by varying the instantaneous recharging power. We provide an economic analysis of the incentives at play, including the EV owners point of view (longer recharging durations and impact on battery lifetime versus cheaper energy) and the aggregator point of view (revenues from recharging versus regulation gains). In particular, we analyze the range of regulation rewards such that offering a regulation-oriented recharging benefits both EV owners and the aggregator. After that, we split the monopolistic aggregator into two competing entities. We model a non-cooperative game between them and examine the outcomes at the Nash equilibrium, in terms of user welfare, station revenue and electricity prices. As expected, competing stations offer users with lower prices than the monopolistic revenue-maximizing aggregator do. Furthermore, the amount of regulation service increases significantly than that in the monopolistic case. Considering the possibility of discharging, we propose an approach close to Vehicle-to-Grid, where EVs can give back some energy from their batteries during peak times. But we also use EVs as energy transporters, by taking their energy where it is consumed. A typical example is a shopping mall with energy needs, benefiting from customers coming and going to alleviate its grid-based consumption, while EV owners make profits by reselling energy bought at off-peak periods. Based on a simple model for EV mobility, energy storage, and electricity pricing, we quantify the reduction in energy costs for the EV-supported system, and investigate the conditions for this scenario to be viable.