Harmonic distortions of multiple power factor compensated EV chargers

Electric vehicle chargers are mostly power converters with power factor correction and waveform shaping features included. Different vehicle makes and models will likely have different charger control and topology. While the charger charging currents have generally low AC waveform distortions, including variety of chargers at the same time can provide even further lower harmonic currents. This is due to harmonic cancellation brought by different harmonic patterns of different chargers. The present paper analyzes the sine distortions and the sum of the harmonic currents of multiple harmonic sources of such type. The inputs for the analysis are the measurements of the commercial EV's harmonic charging current patterns. It will be shown that remarkable harmonic cancellation will be likely if different vehicle types are included in the pool of vehicles charging at the same time. The results presented here for the EV chargers would be valid also for other similar mains interface converters.