# Evaluating Effects of Electric Vehicle Chargers on Residential Power Infrastructure
## 3 Load Profile Analysis of EV Chargers
### Power Analysis  
Another issue analyzed is power consumption. As the electrical system is originally designed for residential use, it may not account for the increased power demands of EV charging. Understanding the behavior of electric power consumption helps in the evaluation of the suitability of installing EV charging equipment without exceeding the electrical system's capacity and affecting the overall system. Additionally, it allows for an analysis of the equipment's effectiveness, facilitating further economic analysis for service providers.  
A graph of the total power is shown in Figure 6. In the graph, which shows the average power (P\({}_{\text{Lavg}}\)) in kilowatts (kW) versus the charging status of the EV charger, a notable difference in energy consumption during charging and non-charging periods is evident. During charging times, the electric power increases significantly, consistent with the power requirements of EV chargers. An instantaneous increase in power can be observed from the peaks in the graph, where P\({}_{\text{t,avg}}\) values reach approximately 12 kW, indicating very high power consumption during these periods.  
However, the electrical power in each range does not remain constant due to the various types of users utilizing the EV charging services. This variability results in different maximum power levels at different times. Additionally, power consumption occurs even outside the charging periods to operate the charger itself, impacting the electrical system, albeit to a lesser extent.  
A deeper analysis considering the power in each phase, as shown in Figure 7, reveals the average power in each phase (P1\({}_{\text{avg}}\), P2\({}_{\text{avg}}\), and P3\({}_{\text{avg}}\)) compared to the charging status at each time. During charging periods, the power usage in each phase, especially 1-Phase, increases significantly, indicating higher power usage to charge EVs. Conversely, during non-charging periods, the power consumption in each phase is greatly reduced.  
Figure 6: Total active power measured over time in relation to EV charger usage.  
According to the charger's specifications, it has a rated power of 7.4 kW for single-phase charging and 22 kW for three-phase charging, with a maximum output current of 32 A in both configurations. From the measurement results, it was observed that the charger typically operated below its maximum rated power. Single-phase charging, which constituted most of the charging events, mostly showed that the measured power ranged between 3.5 and 4.3 kW, reaching a maximum recorded power of 7.2 kW, closely aligning with the charger's rated single-phase power of approximately 7.4 kW. Similarly, three-phase charging consistently remained below the 22 kW specification. These findings are consistent with the compatibility between the charger and the electric vehicles utilized during the test, as many EV models limit the charging power according to their built-in charging capabilities. To ensure the accuracy and validity of these measurement data, repeated tests and the cross-checking of results from two independent measurement points were performed, both of which yielded consistent and reliable readings.  
The profile data collected illustrate varying energy consumption behaviors depending on the behavior and type of service users. This diversity directly impacts the connected electrical system, necessitating infrastructure design that accommodates these possible behaviors. The next section presents a study of the direct impacts on the electrical system in order to provide information for designing an appropriate system.