Impact of Vehicle to Grid Technology on Distribution Grid with Two Power Line Filter Approaches

Vehicle to Grid (V2G) is capable of enhancing ancillary services in the grid by providing regulation up/down when needed. This technology will increase the security of the system by helping transformers and lines not to become overloaded and reducing peak load. However, integrating numerous electric vehicles (EVs) to the grid brings about voltage fluctuations and induces more harmonic distortions to the power distribution system. This paper investigates the impacts of V2G technology on the distribution grid and how the disturbances may be compensated by using harmonic filters to improve the power quality in the distribution grid. Multiple design schemes for power line filter topologies are used. The goal is to propose an effective filter in term of location and size by comparing a single harmonic filter on the distribution line with individual filters on each charging station. The studied model consists of an EV charging station, the corresponding DC/DC converter with its constant current controller, a DC/AC converter with its voltage-oriented controller to link the charging station to the grid, a power line filter, and a distribution grid. The results of different models are compared to each other to draw the main conclusions. The models are used to test the effectiveness of harmonic filters in different scenarios which include ten EV charging stations with a single grid side filter and with individual filters for each charging station.