Control of electric vehicles in modern power grids
The electrification of mobility, particularly electric vehicles (EVs), is a key element in reducing the consumption of fossil fuels. With increasing charging powers and batteries, EVs are becoming dominant loads but potentially also active elements with useful features in the electricity grid. Although the large size of EV fleets connected to the grid may threaten the stability of the power system, they have the potential to serve as supportive units, not only as the widely discussed energy storage units but also as stabilization means. Bidirectional battery chargers of EVs can provide active and reactive power according to so-called vehicle-to-grid, vehicle-to-home, and, in general, vehicle-to-X concepts. Nevertheless, the interaction of EVs with the grid, through their feed-back-controlled power electronics, once they take on an active role, can lead to complexity, particularly with the increased electronification of the grid due to electronic loads, such as power supplies, electronic control gear, or drive inverters replacing previously simple transformers, light bulbs, or grid-connected motors, and generation, particularly in the form of renewable resources. This chapter studies these complexities and develops necessary control techniques for them.