The simple construction method for three-level DC converter based on switch-diode-capacitor network

Three-level (TL) technique can be used to reduce the voltage stress of switches to half and effectively decrease the filter's volume and weight. However, few literatures make further discussions on the construction methods for TL converters. Therefore, a simple construction method for TL DC-DC converters based on switch-diode-capacitor (SDC) network was proposed in this paper. This method was applicable to all non-isolated single-switch converters. At beginning, the definition of the SDC network is presented, and the basic ways of extracting or constructing SDC network are introduced. Next, taking the Buck-Boost converter as an example, this paper expounded the basic steps to construct the TL DC-DC converters based on SDC network structure. Then, the TL topologies of fourth-order DC-DC converters capable of continuous input and output current are deduced by means of this method. As one of the topologies, the Superbuck TL converter was analyzed in detail. Lastly, the validity of theory analysis is verified by the experiment results of a 100W/100kHz prototype.