Diagnostics of Supraharmonics in Terms of Analysis of Electric Vehicle Charging

Charging electric vehicles is a non-stationary process that affects the power quality in different ways. Depending on the power of the electric vehicle charger, its topology and the connection point in the power system change. For on–board chargers, the power supply directly from the household in the low–voltage network is sufficient. Taking into account the fact that current policies and trends on global markets result in an ever–increasing number of electric vehicles in use, it is also possible that power quality can deteriorate due to the increased share of on-board chargers on the low–voltage side. Electric vehicles, depending on their topology and the properties of the power supply circuit, can cause various disturbances of power quality. One of the common disturbances of power quality that result from charging an electric vehicle is the signal distortion caused by supraharmonics. Unfortunately, because of the low value of these components and the commonly used power electronics, it is difficult to identify power quality parameters, including spectrum components, associated only with the electric vehicle charging process. The article proposes an approach supporting the selection process of available values related to charging an electric vehicle. Obtained results in the field of power quality are presented for various on–board chargers of electric vehicles under the conditions of the simultaneous occurrence of other sources of power quality disturbances.