IoT Based Online Harmonic Emission Estimation of DC Fast Chargers

MSc thesis of Yawen Liang

In emerging fast-charging stations, DC fast chargers (DCFCs) are employed which rely on power electronics and control to achieve the required performance. Harmonic current emission induced by the complex system behavior is of great concern in the DC fast charger (DCFC) system. This thesis proposes a harmonic emission model for the typical DCFC design, i.e., the two-level active front end. The technique is based on the Fourier series method and the impedance model which is able to reveal the harmonic current emission of DCFCs under different grid conditions. Additionally, an IoT based online harmonic emission estimation tool for DCFC is built based on the aforementioned proposed model in this thesis.