Impact of Electric Vehicles on the Distribution Grid

Abstract

With the growing concerns over climate change, global warming, rapid urbanization, and energy security, the focus of the global community is shifting towards clean, green, and sustainable energy resources. Electric Vehicle (EV), because of its low well-to-wheel greenhouse gas emissions and zero tailpipe emission, finds a central place in several international and national initiatives and policies. Thus, the future distribution grid is likely to witness a surge in the penetration of EVs. This increasing penetration of EVs into the grid requires proper analysis and planning to ensure a smooth transition to the new EV regime. Detailed analysis helps in minimizing the negative impacts of Electric Vehicles Grid Integration (EVGI) and in harnessing the positive benefits, thereby improving the operation of the distribution grid. The aim of this report is to analyze the impact of EVs on the distribution grid. A detailed literature review on EV modelling and the impacts of EVGI is presented. The IEEE 13 and IEEE123 Node Test Feeders are used for the analysis. A 24-hour profile is assigned to the loads and the EV is modelled as a Constant Power Load (CPL) during the Grid to Vehicle operation. The EVs available in the Indian market are studied and are fit into the CPL model. The entire system is modelled in the Open Distribution System Simulator (OpenDSS). The load flow analysis is carried out using the MATLAB-OpenDSS COM Interface. Different charging scenarios- Concentrated Charging, Uncoordinated Charging, and Coordinated Charging- are simulated using the proposed rule based strategy. The subsequent impact on the voltage drop, network losses, system peak load, load profile, transformer overloading and phase unbalance is recorded and analyzed. Monte Carlo Simulation is performed to depict the effect of uncertainties in State of Charge of EV, EV arrival time, type of EV and its charging duration.