Distribution Bus Voltages as a Metric for Grid Health Considering Widespread Public EV Charging

The widespread adoption of electric vehicles (EVs) is raising attention to the impact of EV charging on grid health conditions, as increasing public EV charging loads are being added to the distribution grid. This paper presents a study conducted to evaluate the effectiveness of using distribution bus voltages as a metric for evaluating grid health considering widespread public EV charging. Using the Caldera software and distribution network models created with the OpenDSS modeling software, the effect of EV charging on the grid power distribution network has been studied in this work. The IEEE 34-bus system and a distribution network in downtown Salt Lake City, Utah USA are used as study cases in the work. The results of the study are time-series voltage data at select buses on each network. Analysis of the results and comparison of the studies show voltage violations can occur on the IEEE 34-bus system due to public electric vehicle charging loads, but no violations were observed in the actual grid power distribution network in downtown Salt Lake City. Based on the case study results, analysis, and comments, insights have been provided in this paper to further discuss the effectiveness of using distribution bus voltages alone as the metric for grid health. Through the analysis, case studies, and system simulations, this paper concluded that distribution bus voltages alone may not be a sufficient metric in determining grid health considering widespread public electric vehicle charging.