Development of a 100 kW High Output Voltage Full Bridge LLC Resonant Converter

Abstract

The aim of this master thesis project is the development of a 100 kW high output voltage LLC resonant converter, which is based on Silicon Carbide Metal-OxideSemiconductor Field-Effect Transistors (SiC MOSFETs). Possible application scenarios for the developed converter include the usage as a high voltage capacitor charging power supply for a voltage of up to 40 kVp, or the application as a plasma generator. Initially, the LLC resonant converter topology is described mathematically by the usage of First Harmonic Approximation (FHA) in order to derive a selection process for the passive component values. After this step, the design and dimensioning process of the passive resonant components is explained. In addition to that, the development process of the full bridge used in the LLC converter is outlined and how the selection of the switching frequency influences soft switching conditions. Finally, a controller design based on Pulse Density Modulation (PDM) is proposed and applied to the LLC resonant converter, as it offers a number of benefits in terms of switching loss reduction compared to other control approaches. At the end, the finished LLC resonant converter is evaluated in terms of soft switching behavior, load step response, achieved output characteristics and efficiency.

Datum der Bewilligung	2024
Originalsprache	Englisch
Betreuer/-in	Mario Jungwirth (Betreuer*in)