Zare, Afshin RezaeiBabaeiyazdi, Iman2020-05-112020-05-112019-082020-05-11https://hdl.handle.net/10315/37355In this thesis, the aim is to investigate the unbalanced voltage behaviour of the fast charging stations and their effects on distribution power systems. In the first stage, the fast charger is developed to derive the response of the charger to the unbalanced input voltage. This response allows us to model the charging station as a load in power flow analysis. In the next stage of the study, a simplified model is proposed to incorporate the behaviour of the fast charger in power flow analysis. Different feeders data of IEEE benchmarks such as IEEE 34-bus, 37-bus, and 123-bus are used in the base benchmark, which is IEEE 30-bus, using the proposed simplified model. Then, maximum charging capacity of the stations and unbalanced voltage ratio (UVR) is calculated for any bus of interest that the charging station has been connected to. This task is done while the system is exposed to two constraints of UVR and voltage. The power flow analysis results indicate that for the different feeders data, UVR of the system after connection of charging stations is the dominant constraint for some buses and it prevents further integration of fast charging station to the distribution system. Therefore, in order to mitigate unbalanced voltage in the system, partial transposition is utilized. In the partial transposition, the feeders are transposed and divided in two equal sections. After applying partial transposition to the feeders data, for the case of IEEE 34-bus, the UVR after connection of charging station was below the permissible value of 3%, but for IEEE 37-bus and 123-bus some buses still suffer from high UVR. Accordingly, a modified partial transposition was adopted as another alternative. The results demonstrate that the UVR of the system after applying modified partial transposition to the feeder data of IEEE 37-bus and 123-bus has decreased below the standard value of 3% and the system can accommodate higher capacity of fast charging stations. Finally, according to the power flow analysis a power distance table is acquired for the feeders data that predicts the maximum charging capacity that can be connected to the system based on its distance from the main source without violating the systems operational constraint.Author owns copyright, except where explicitly noted. Please contact the author directly with licensing requests.Electrical engineeringElectronic Thesis or Dissertation2020-05-11Power systemFast charging stationTranspositionPower distance tableVoltage instability