Comparative Assessment of Electric Vehicle Charging Impacts on the IEEE 33-Bus and Ayepe 34-Bus Distribution Networks
Olufunso Kehinde *
Department of Electrical/Electronic Engineering Technology, Osun State College of Technology, Esa-Oke, Osun State, Nigeria.
Gafari Adepoju
Department of Electronic and Electrical Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
Oluwaseyi Adebiyi
Department of Electronic and Electrical Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The increasing adoption of electric vehicles (EVs) introduces additional demand into existing distribution networks, potentially increasing power losses and weakening voltage stability. This study comparatively assesses the technical impacts of electric vehicle charging stations (EVCSs) on the IEEE 33-bus benchmark and Ayepe 34-bus practical distribution networks in Nigeria. A 20% EV penetration level was considered for both networks, with EVCSs modelled as constant active-power loads operating in grid-to-vehicle mode at unity power factor. A Direct Load Flow technique was implemented in MATLAB R2023a to evaluate real power loss, reactive power loss, and Average Voltage Stability Index (AVSI) under three conditions: base case, EVCS-only, and EVCS with Unity-Power-Factor Distributed Generations (UPF-DGs). The EVCS capacities were 1.529 MW and 1.628 MW for the IEEE and Ayepe networks, respectively. EVCS integration resulted in additional real power losses of 5.72 kW/MW (4.14% increase) in the IEEE network and 21.87 kW/MW (4.67% increase) in the Ayepe network, while reducing AVSI. The optimal allocation of the three UPF-DG units using artificial rabbits optimization subsequently reduced real power loss by 65.56% in the IEEE network and 80.98% in the Ayepe network relative to their EVCS-only conditions, while substantially improving voltage stability. The findings demonstrate that EVCS impacts depend strongly on feeder characteristics and that appropriately allocated UPF-DGs can effectively mitigate EV-induced technical deterioration.
Keywords: Average voltage stability index, direct load flow, electric vehicle charging station, radial distribution network, distributed generation, power loss