Intelligent Electric Vehicle Integration - Domain Interfaces and Supporting Informatics

Abstract

This thesis seeks to apply the field of informatics to the intelligent integration of electric vehicles into the power system. The main goal is to release the potential of electric vehicles in relation to a reliable, economically efficient power system based on renewables. To make intelligent EV integration a reality, it is prudent to understand the domain in its entirety. In this thesis, this is reflected by a thorough investigation of the stakeholders most relevant to the synergistic relationship between electric vehicle and grid. The rst investigation addresses the power market. The market can give system operators access to the exibility of electric vehicles while at the same time creating an immediate economic incentive for the EV owner. A fleet operator is introduced to allow a fleet of electric vehicles to participate in the markets. Examples are provided on the specic markets and services in which the electric vehicle may be best suited to participate. The next stakeholder investigated is the distribution system operator representing the low voltage grid. The challenge is assessed by considering a number of grid impacts studies. Next, a set of grid congestion mitigation strategies are proposed with a special attention to the impact that congestion would have on the operation of a fleet operator. The third and most important stakeholder is the electric vehicle owner. The emphasis is on the plug in patterns of a number of Danish electric vehicle drivers. The objective is to understand how owner behavior will influence charging flexibility. It is indicated how plug in behavior may be predicted and how the resulting flexibility may be applied to achieve several different goals. After having investigated the aims, constraints and requirements for the above stakeholders, the attention, in the second part of the thesis, is turned to three vital topics within the eld of informatics. The first topic is the control architecture that determines the placement and relationship between control systems used to control electric vehicle charging. A centralised market-based architecture is chosen and the functionalities needed by the control logic are demaned. The next informatics topic, communication, describes a set of protocols and standards applicable for electric vehicle integration. The study investigates the IEC 61850 standard and its ability to support smart charging. Finally it is described how considerations to each of the stakeholders can be included in the optimization done by the fleet operator. It is shown how dierent markets can be considered and how stochastic optimizationcan be used to model uncertainty in regards to plug in behavior and grid congestion. A large part of the above work have been done as contributions to the EDISON project in which the Thesis Author has participated. During the project the author has built a technical platform for testing several of the technologies mentioned above, against a small fleet of electric vehicles. This thesis is meant as an input for market players, system operators, fleet operators, fellow researchers and anyone with an interest in the role of the electric vehicle in the future power system.