Indirect connections in EV charging infrastructures for grid stability

...... The EV battery will actively contribute to the frequency variation/disturbance of the power grid system if not controlled for. If the grid is persistently disturbed, the power flow between the grid and the EV battery cannot reliably provide fast charging conditions for the EV ......  

...... The worst-case scenario includes complete failure of the grid system and the power plant unable to supply sufficient power to their designated areas, resulting in a blackout; such pitfall may occur when more than hundreds of level 3 charging stations are connected to a single Point of Common Coupling. This will impose a tremendous problem on the grid stability due to fluctuations of frequency and reductions of power factor at the Point of Common Coupling ......

.... The biggest difference with the ERR system compared to the existing methods of EV charging stations and Energy Storage systems, which use electricity via direct (active) connections to the power line, is that the ERR system can minimize the impact on grid systems and power plants by eliminating frequency fluctuations and improving the power factor.