## 3 Experimental Results and Validation  
### Effect of Charging Strategies of Fleet of EVs on Peak Sharing and Valley Filling  
Fifteen charging strategies, including three Overnight, three Workplace/Other Charging Sites, and nine Overnight_Workplace/Other Charging Sites profiles (Table 1), were developed for comparative analysis and to verify the performance of the proposed charging strategy. It is observed that the peak charging load during the three-day-ahead period occurred around 7 p.m. (Figures 3 and 4). The energy performance of residential electric load profiles was evaluated using Twin test houses, specifically single-detached units, by the Canadian Centre for Housing Technology (CCHT) [27; 28]. As can be seen from Figure 5, the residential peak load occurred around 8 p.m. The simultaneous peaking of residential and electric vehicle (EV) loads can place significant strain on the energy grid. Shifting or transferring peak EV charging to Overnight or Workplace/Other Charging Sites hours can enhance energy efficiency and improve grid stability. Figures 3 and 4 illustrate that a charging strategy (CS1 \(\times\) CS4) with a 40% load shift for hybrid Overnight Workplace/Other Charging Sites is more effective than single Overnight charging (CS1, CS2, and CS3) (Figures 3a and 4a) or single Workplace/Other Charging Sites (CS4, CS5, and CS6) (Figures 3b and 4b) during peak periods in spring and winter. This strategy effectively reduces peak electricity usage and excels in both peak shaving and valley filling over a three-day prediction period. Similar results in reducing electricity demand during peak periods using Overnight and Workplace/Other Charging Sites' have been observed in various experimental studies [13; 16].  
The comparison between the aggregated load in spring and winter revealed that peak periods in spring are shorter than in winter, resulting in a higher overall charging power during winter (Figures 3 and 4). This might be due to reduced battery efficiency, increased cabin heating load, and less effective regenerative braking. The average power during peak periods is 745 and 581 kW, reduced to 391 and 301 kW for winter and spring, respectively (Tables 3 and 4). These findings demonstrate the potential for three-day-ahead EV charging strategies to significantly reduce residential loads and costs in peak periods and improve grid stability. Overall, the experiments validate the effectiveness of charging strategies based on predicted load using the ML approach.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Period** & **Cents/kWh (CADS)** & \\ \hline
7 a.m.-11 a.m. & Peak & 13.4 \\
11 a.m.-5 p.m. & Mid-Peak & 9.4 \\
5 p.m.-7 p.m. & Peak & 13.4 \\
7 p.m.-7 a.m. & Off-Peak & 6.5 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Weekday TOU hours in Ontario.  
Figure 3: Charging strategies, prediction, and actual aggregated charge power during the day in spring from 30 April 2019 to 3 May 2019. **(a)** Overnight Charging. (**b**) Workplace/Other Charging Sites. (**c**) Hybrid Overnight Workplace/Other Charging Sites strategies.  
Figure 4: Charging strategies, prediction, and actual aggregated charge power during the day in winter from 26 January 2019 to 29 January 2019. (**a**) Overnight Charging. (**b**) Workplace/Other Charging Sites. (**c**) Hybrid Overnight Workplace/Other Charging Sites strategies.  
Figure 5: CCHT research house electrical load profiles.