## 3 Results of Measurements
### Voltage Harmonics during Vehicle Charging  
One of the important parameters for users are those connected with the charging process. While in the case of DC charging, the charging time for a passenger car usually does not exceed several minutes to 1 h, depending on the desired charge level, in the case of AC charging, this time is much longer. Therefore, knowledge of this process is important, especially for users who charge their vehicle batteries at home. To investigate the impact of charging an EV on the home electrical installation, a number of tests were carried out. Charging power curves for individual vehicles are presented below (Figure 11). Figure 11: _Cont._A significant difference was observed during this process, with significant fluctuations in current consumption when the batteries reached a charge level greater than 80%. During the last 20%, the current consumed varied from 1 to 32 A. In addition, it was the only time when the cooling fans of the charging system and batteries turned on after charging. In the case of scooters, charging was as follows: for BMW C evolution, charging was linear with full power, except that in the last stage (the last few percent of capacity), in which there was an exponential decrease in power consumption from the network; in the case of the second scooter, an older example of an unknown brand, the power consumption, and thus the current, oscillated around the maximum value of the charger current throughout the charging process, and at the end, it dropped to the minimum value in a short time; the kick scooter, on the other hand, drew very little current throughout the charging process;  
Figure 11: Power curves for different electric vehicles: (**a**) for the BEV (11 kW three-phase AC charger); (**b**) for the PHEV (7.4 kW single-phase AC charger); (**c**) for the scooter (2.4 kW single-phase AC charger (Brick)); (**d**) for the kick scooter (3 A, single-phase AC charger (Brick)). moreover, frequent steps of 10 W can be noticed; because of method of operation of the charger--it worked with this step. A significant load on the installation may result in a voltage drop in individual phases. As long as the load is symmetrical, this effect is not dangerous, but significant asymmetry in the case of a single-phase load, while home loads are usually single-phase, may result in very high current in the neutral line or voltage asymmetry in the other three-phase loads (e.g., utility water heaters). Phase voltages waveforms is presented for the least favorable case, i.e., the plug-in hybrid (Figure 12). Figure 12: Voltage during charging for different electric vehicles: (**a**) for the BEV (11 kW three-phase AC charger); (**b**) for the PHEV (7.4 kW single-phase AC charger). In the case of a scooter and kick scooter, voltage changes did not exceed 3 V. It can be seen that the voltage drop is significant for the highest value of the current, but voltage did not exceed the limits of the permissible value range. Another analyzed parameter was the analysis of distortions caused by the nonlinearity of the load, which is the on-board charger. A potential threat is the impact of the presence of higher harmonics on other loads. Despite these differences, it was observed that in none of the analyzed cases were the normative quality parameters of electricity exceeded. At the same time, the analysis of the harmonic distribution showed that the chargers generate current and voltage harmonics in the range from the DC component to the 50 th harmonic, the distribution of which depends on the vehicle. The harmonics spectrums registered during the charging process for the VW ID.3, the Fiat 500e, and the Kia eNIRO, are presented in the Figure 13 respectively. Only the first 25 harmonics are shown, because; components with orders over 25 are negligibly low. Figure 13: Cont.