Self-Precharge in Single-Leg Flying Capacitor Converters

Abstract

Flying Capacitor (FC) multilevel pulse width modulated (PWM) converters are an attractive choice due to the natural voltage balance property. During start-up of the converter, care has to be taken that the power switches are not exposed to voltage overstress due to uncharged capacitors. A flying capacitor self-precharge technique is proposed which, by making use of natural balancing and a DC-bus rate control, makes the capacitors balance with a zero average load current. The DC-bus rate control depends on the capacitor voltage balance dynamics. The regular PWM natural balancing technique gives good results for even-level single-leg converter self-precharge, for odd-level converters a special switching pattern is necessary.

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Cite this paper

@inproceedings{Thielemans2009SelfPrechargeIS, title={Self-Precharge in Single-Leg Flying Capacitor Converters}, author={Steven Thielemans and Alex Ruderman and Jan A. Melkebeek}, year={2009} }