A study on capacitor charger using variable frequency inverter as a high repetitive pulsed power modulator

Various methods exist for capacitor charging circuits, but for all, a high frequency inverter is indispensable to realize high repetitive operation of the pulsed power modulator. While high frequency operation of the inverter is effective in charging voltage accuracy, the switching loss increases in proportion to the frequency of the inverter. This study utilizes a half-bridge circuit as inverter circuit to the charger characterized by the following components: The switching device is a SiC-based MOSFET (Silicon-Carbide based Metal Oxide Semiconductor Field Effect Transistor), and the converter circuit uses high-speed SiC-based diodes. After simulating capacitor charging circuit loss while varying operating frequency of the variable frequency inverter, we analyzed the stability of the charging voltage, continuous operation, and downsizing of charger.