Comparative Analysis of Charging Modes of Series-Resonant Converter for an Energy Storage Capacitor

This paper discusses charging modes of series-resonant converter (SRC) for an energy storage capacitor in terms of charging time, losses of switch, normalized peak resonant current, normalized peak resonant voltage, and switch utilization in three operational modes. Principles of operation on the full-bridge SRC with capacitor load are explained, and charging characteristics in discontinuous and continuous operational modes are analyzed. Based on the analysis and the simulation focused on the aforementioned five performance indexes,
ms
= 0.5 is evaluated to be the optimized operating frequency ratio for charging an energy storage capacitor. A 1.8-kJ/s SRC prototype is assembled with the TI 28335 DSP controller and a 40-kJ 7-kV capacitor. Design rules based on the comparative analysis are verified by experiment.