Three-level converters-a new approach for high voltage and high power DC-to-DC conversion

The most important advantage of the half-bridge (HB) three-level (TL) power converter is that the voltage stress of the switches is only the half of the input voltage. This paper presents the derivation of HB TL converter, and from which two TL switch cells are extracted. The derivation of HB TL converter is extended to all DC-to-DC converters, and a family of TL converters are proposed. In addition to the reduction of the voltage stress of the switches, some TL converters have the merit that the filter can be significantly reduced, which improves the transient response. TL converters are very suited for high input/output voltage and medium-to-high power DC-DC conversions.