High State Count Power Converters: an Alternate Direction in Power Electronics Technology

The general trend in power electronics devices has been to switch power semiconductors at increasingly high frequencies in order to minimize harmonics and reduce passive component sizes. However, the increase in switching frequency increases the switching losses which become especially significant at high power levels. One approach to avoiding these losses is to utilize soft switching converters. However, this typically increases converter cost due to higher power electronics requirements and additional passive components. An alternate approach is to utilize high state count converters which use a large number of semiconductor devices to provide a high number of possible switching states. This allows lower switching frequency operation for a given performance, thus reducing switching frequency and reducing switching losses. The purpose of this paper is to discuss the use of high state count converters as an alternative to soft switched technologies.