Probabilistic assessment of the impact of plug-in electric vehicles on power quality in electric vehicles on power quality in electric distribution systems.

Abstract

The electrification of the transportation sector may have socio-economic benefits such as reducing greenhouse gases, lowering the soaring gas prices, and ending the reliance on imported oil. The integration of plug-in electric vehicles into the electric distribution system may pose potential power quality problems due to the uncertainties in the number of these vehicles, their charging time and locations. Several power quality phenomena such as voltage deviations, voltage imbalance, transformer overload and unbalance are investigated in this thesis. Since the problem is of a stochastic nature, a probabilistic approach using Monte Carlo simulation is adopted in this work to assess potential impact on power quality in the distribution system and hence addressing the uncertainties associated with integrating those electric vehicles. The analysis presented in this work also considers different vehicle types (i.e., plug-in hybrid and battery electric vehicles) for automobiles and pick-up trucks, vehicle penetration and vehicle charging levels. The results of Monte Carlo simulation reveal that Plug-in Battery Electric Vehicles and level 2 charging contribute most impact on undervoltage and transformer overloading, whereas level 1 charging contributes most impact to load unbalance on transformers. Recommendations are made to mitigate such impacts for future work.