Predicting the zero-voltage switching profiles of half-bridge driven inductor-less piezoelectric transformer-based inverters

A methodology for predicting the ability of an inductor-less driven piezoelectric transformer (PT)-based inverter to achieve zero-voltage switching (ZVS) is presented. Cyclic-mode analysis is used to derive a model of the PT operating in the vicinity of ZVS. The output of the model is a normalised parameter that indicates the PT-based inverter´s ability to achieve ZVS for a given operating condition. Subsequently, the model is employed to generate the ZVS profiles of a PT-based inverter that indicates regions where ZVS can be achieved and provides the loci of the operating frequency and dead-time when working at the ZVS boundary. The ZVS profiles of two PT-based inverters with different characteristics are presented to highlight the need to consider the ZVS loci when selecting a PT for a given application.