## 7 Impact Assessment of EVs
### Existing Solution of EV Integration with Grid  
The integration of EVs into the grid has several positive impacts on grid stability. The EVs must be carefully placed into and utilized in the system for the frequency and voltage support of the grid. Improper utilization of EVs adversely affects the voltage and frequency stability of the grid. However, various alternative technologies and approaches are reported in the literature for the integration of EVs into the grid [149; 150]. These approaches include distributed energy resources (DERs), demand response, EV charging management, co-ordinated EV charging, smart charging, vehicle-to-grid technology, etc. Some Existing Solution of EV Integration with Grid:  
* Smart Charging: This innovation optimizes the way EVs are charged to save the power grid from overload. It allows EV charging to be scheduled based on the availability of renewable energy or during the off-peak hours. * Smart Grid: Smart grids are built to automatically detect, monitor, and regulate the flow of energy between power generators and end users using the information and communication technology. In smart grids, EVs can be charged and discharged in a coordinated way that also allows renewable energy sources such as solar and wind power to be integrated into the system. * EV-Charging Management Systems: These systems can help maximize the amount of energy that EVs draw from the grid, reducing the load on distribution networks and the distribution transformer. By offering usage-based or dynamic tariffs, these systems can also help reduce the cost of EV charging. * Demand Response: By incentivizing e-vehicle owners to charge their cars during off-peak hours (e.g., evenings), utilities can reduce peak demand. This reduces the burden on the system, provides better regulation service, and reduces the possibility of congestion in the grid. * Vehicle-to-Grid (V2G): EVs can provide electricity to the grid according to V2G technology. By supplying extra energy during the peak hour's periods, this helps the frequency regulation service for the grid. * EV/Grid Interoperability Standards: The safe and effective integration of EVs into the grid can be ensured with the aid of EV/grid interoperability standards. The gear and software used for EV charging may be made compatible with the grid as a result of these standards. * Renewable Energy Sources: EVs may be charged using renewable energy sources like solar and wind energy. This lessens the dependency on conventional energy resources and lowers greenhouse effects. * Battery Storage: When there is a large demand for EVs, battery storage technology can be utilized to charge them. It also allows for the storage of extra renewable energy. \begin{table}
\begin{tabular}{c p{142.3 pt}} \hline \hline
**Challenges** & **Remarks** \\ \hline Fluctuation in Voltage & The level of integration and charging rate of EVs have a significant impact on voltage fluctuations. The effect grows with both the rate of charging and the amount of people who are being charged. \\ \hline Voltage Swell & The increased use of single-phase charging for EVs has a larger effect on voltage imbalance. It may cause the grid voltage stability. \\ \hline Losses & Unregulated and single-phase EV charging systems cause more power loss. Increased EV penetration leads to overloading and power losses in distribution transformers. \\ \hline Harmonic & The impact of EV penetration on harmonics varies with the level of penetration, and grows with both the level of penetration and the charging rate. Additionally, uncontrolled EV charging leads to an increase in harmonics. \\ \hline Frequency Imbalance & The impact of integration and penetration of a large number of EVs leads to the considerable change in frequency mismatch. The uncoordinated way of charging of the large number of EVs leads to frequency imbalance of the grid. \\ \hline \hline \end{tabular}
\end{table} 
Table 23: Challenges of EV integration with regard to the power quality. This will result in a reduction of energy costs.