Stochastic Assessment of Plug-in Electric Vehicles Charging in LV Distribution Network on Voltage Unbalance

The worldwide application and off-grid charging of plug-in electric vehicles (PEVs) are expected to grow in the next few years tremendously. However, uncoordinated PEV charging in low-voltage (LV) distribution networks can lead to grid problems such as transformer overloading and voltage unbalance. A potential solution and also a key challenge for PEV integration is the smart shifting of charging activities from peak hours to off-peak. In this background, this paper investigates the impacts of stochastic single-phase PEV charging based on time, rating and location of charging at residential houses on voltage and voltage unbalance factor (VUF). Additionally, Monte Carlo simulation is applied to describe the stochastic behaviour of PEVs. Different aspects like penetration level, PEV charging rate and location are investigated to better understand the impacts of PEVs on the LV distribution network. The impacts of uncoordinated and coordinated PEV charging on VUF and voltage profiles are simulated on a real Western Australian distribution network in the Perth solar city over 24 hours.