Software-based Power Factor Correction by using Iterative Learning Control for Battery Chargers with LLC Resonant Converter Topology

Inhalt:
The weight and volume of battery chargers play an important role for small electric vehicles. In our paper we propose a control design based on Iterative Learning Control (ILC) to control the pulsed charging current of a compact battery charger based on the LLC topology without a DC-link capacitor, while accomplishing the desired Power Factor Correction (PFC) functionality at the same time. Removing the DC-link capacitor along with the PFC stage provides significant cost savings, reduced hardware complexity and increased power density. The control-oriented converter model, the control design as well as results of extensive simulation studies are presented in detail. Important remarks on stability and on robustness issues are given. The simulation studies show promising results.