On the Global Harmonic and Supraharmonic Emission of an Electric Vehicle Charging Station: Investigation of Aggregation and Diversity

The increasing number of electric vehicles (EVs) connected to distribution networks can have a significant impact on Power Quality deterioration. In particular, waveform distortions can increase due to the rising levels of disturbances at both low frequency and high frequency. This is a companion paper to a paper in which the emissions of a single low-power charging EV are analyzed. However, when an EV charging station recharges several EVs it is necessary to investigate the cumulative emissions of the EV charging currents and to evaluate the aggregate spectra at the traditional low frequency band (below 2 kHz) and at high frequency (up to 150 kHz). The objective of this paper is to investigate the cumulative emissions taking into account the interactions due to a shared source impedance, the power level of EVs, and the variations in circuit parameters. Novel aggregation and diversity factors defined for harmonic and supraharmonic frequency bands are evaluated, predicting the cumulative emission behavior of several EVs connected to a low voltage distribution system.