Impact of Electric Vehicle Integration on Short Circuit Capacity of Distribution Network

The protection systems of traditional distribution networks are typically set up in a radial configuration with the primary source supplying power: However, integrating bidirectional power sources like electric vehicles (EVs) and distributed generators (DGs) pose various challenges in the design of protection strategies. The challenges arise primarily due to increased short-circuit level of the system, change in the power flow direction, loss of coordination within relays, overcurrent protection issues, etc. This study evaluates the impact of EV penetration level and DG integration in four different scenarios: Grid-to-Vehicle (G2V) unidirectional charging, G2V with DG integration, Vehicle-to-grid (V2G) bidirectional charging, and V2G with DG integration. The simulation study is carried out on a detailed dynamic model of a real-life distribution system developed in DIgSILENT PowerFactory. The analysis of the obtained results highlights the need to upgrade the existing protection system for the growing presence of low-carbon technologies in Indian distribution networks.