Impacts of G2V and V2G power on electricity demand profile

Successful integration of growing number of energy-efficient electric vehicles (EV) into existing power grid necessitates the study of impacts posed by their adoption in larger numbers. However, their gradual adoption will give sufficient time to the utilities for planning the infrastructure upgrades to prevent destabilization of power network. The work presented in this paper investigates the proportion of energy that can be injected back into the grid by EVs through vehicle-to-grid (V2G) mechanism. The V2G energy profiles are obtained using constant power discharging approach for various power levels (as per charging standards) during the time vehicles are parked. For charging, constant power followed by constant time charging approach is used in succession complying with Li-ion battery charging characteristics together with a constraint of retaining reasonable battery lifetime. The simultaneous effect of V2G power and resulting G2V load on typical daily load curve is figured taking modified IEEE 30-bus as a test system.