Impact of vehicle to grid in the power system dynamic behaviour

摘要

The development of this thesis is devoted to the exploitation of two important sectors that up until now did not have a relevant direct connection, the electric power system and the road transportation sector. The integration of Electric Vehicles (EVs) in the vehicle fleet will impose deep modifications to both sectors and may contribute for the reduction of greenhouse gases emissions as EV expansion is expected. In relation to the transportation sector, alongside with the conventional gas stations, sufficient recharging facilities should be provided to EV owners, either charging at home or by providing public charging infrastructures. In any case, in the electricity sector, Distribution System Operators (DSOs) will have to cope with a new load that before was not included in planning and operation.;The work presented in this thesis involves the development of new functionalities for EV charging control to enhance frequency related ancillary services provision. EVs may play a crucial role in the operation of the power systems, enabling further expansion of Renewable Energy Sources (RES) integration. Therefore, the thesis comprises three main stages, the definition of an integration framework for EVs, the development of primary frequency control techniques with EVs for isolated systems and the integration of EVs in the Automatic Generation Control (AGC) operation for provision of secondary reserves in interconnected systems.;The definition of an EV integration framework promotes the change from a "fit-and-forget" policy to the active EV management and control, implying the creation of a full integration framework. This framework should be able to deal with the technical aspects of electricity grids operation and with market operation. The technical operation layer of the integration framework is managed by the DSO and expands the concepts of Microgrid and Multi-Microgrid to establish a hierarchical control structure. For the market layer, a new player should be introduced for aggregating EVs and represent them in the electricity and reserves markets, the Aggregator. This layer should have a similar hierarchical structure to the technical layer, in order to be able to share the communication path.;Then, primary frequency control techniques with EVs were defined using droop control and inertial emulation to mimic the behaviour of conventional generators. These techniques were using the simulation software Eurostag in a small isolated system, as isolated systems have reduced inertia and so dealing with imbalance situations between load and generation may lead to large frequency deviations.;Finally, EVs were integrated in the AGC operation for provision of secondary reserves in interconnected systems, as interconnected systems present different challenges regarding RES integration. Due to higher inertia values the main issue is to guarantee sufficient secondary reserves. The AGC operation with EVs was assessed using PSS/E in a test network.;The possibility of increasing the integration of intermittent RES was evaluated for both case studies.