Comparison of Methods for Modelling Electric Vehicle Chargers for Harmonic Studies

As a significant increase of electric vehicles (EV) is expected in the future, studies of the impact of this new technology on the harmonic levels in distribution grids are very important. Realistic simulation results require reliable and accurate models of EV chargers, which generally utilize complex circuits including control algorithms for the active PFC. As part of a research project on the impact of high EV penetrations on the harmonic levels in public low voltage networks, a time-domain and a frequency-domain approach for the design of such models have been studied and compared in terms of difficulty, development effort and accuracy. The paper discusses in detail the methodology for the development of both types of models and summarizes their specific advantages and drawbacks, for both assessing performance of individual devices and for analyzing their interactions in network simulations. Based on different objectives, the conclusions provide guidance on the preferred modelling approaches for efficient and reliable network simulations.