Probabilistic quantification of voltage unbalance and neutral current in secondary distribution systems due to plug-in battery electric vehicles charging

• The impact of plug-in electric vehicles on voltage unbalance and neutral current has been quantified.
• The charging demand of plug-in electric vehicles has been probabilistically modeled.
• Monte Carlo method is used to probabilistically quantify the voltage unbalance and neutral current in the secondary distribution system.
• Numerical results due to different PBEVs charging configurations and penetrations are presented and discussed.

The work of this paper investigates the expected impact of level 1 plug-in battery electric vehicle charging on increasing voltage unbalance, undervoltage violations, and neutral current within secondary distribution systems. Plug-in battery electric vehicles charging have been probabilistically modeled using a Monte Carlo simulation, which determines the expected impact on a secondary system extending from the IEEE 34 bus test distribution system. The impact of electric vehicle charging is compared for different penetration levels, different charging methods, and different proportions of electric vehicles charging on either split phase in the secondary system. Results of the Monte Carlo simulation show voltage unbalance and neutral currents are greater when electric vehicle charging is biased to one split phase as opposed to equally distributed amongst both split phases. Furthermore, voltage unbalance is found to increase the number of undervoltage violations experienced in the secondary system.