Impact Assessment of Residential Electric Vehicle Charging on the LV Distribution Grid in Uganda
Abstract
Considering Uganda’s focus on energy sustainability and the electrification of transportation, this research focuses on the implementation challenges of electric vehicles (EVs) in Uganda. Uganda recognizes the urgency of addressing climate change and reducing greenhouse gas emissions and to accomplish this, the nation aims to integrate renewable energy sources into its power grid and promote the adoption of EVs. However, uncertainties remain regarding the power system’s generation, transmission, and distribution networks’ capacity to sustain the EVs and their associated charging loads. This study examines the impact of PEV charging on a representative Low Voltage (LV) grid, using a section of the distribution grid in Kololo - Kampala district, as a case study. The research provides an overview of electric vehicle charging characteristics and employs computer simulation through DigSILENT PowerFactory to model and predict distribution system distortion and load demand resulting from
EV charging. The analysis includes an exploration of the uncontrolled charging
scenario and investigates different penetration levels of PEVs (12.5%,25%, and50%). The 24-hour time simulations reveal noteworthy impacts on transformer loading, feeder loading, and system losses in the LV grid under the uncontrolled charging
scenario. In response, proposed solutions such as transformer upgrades and the implementation of indirectly controlled charging scenarios are discussed. This research also contributes to a better understanding of the challenges associated with installing EV charging infrastructure on the low-voltage grid and comprehensive studies are crucial for assessing the impacts on LV grid operation.