Soft switching voltage regulation for inductorless piezoelectric transformers: a cyclic mode analysis

This paper describes a novel methodology for predicting the ability of an inductorless driven piezoelectric transformer (PT)-based H-bridge inverters to simultaneously achieve zero-voltage switching and output regulation. A new idea for output voltage regulation by controlling deadtime interval is presented. A model is derived using cyclic-mode analysis to estimate the state-variable parameters of the circuit for a given operating condition. The model is then used to demonstrate operation in the zero-voltage switching (ZVS) region and to estimate the deadtime period, load and operating frequency along the ZVS boundary. The output voltage regulation profile is presented and regions where voltage regulation can be continuously achieved while still obtaining ZVS are shown. Both SPICE simulation and experimental results taken using a ring-dot radial-mode PT are presented as verification. The proposed method for a H-bridge PT-based inverter is able to achieve a 5V output from 15V-60V input with simultaneous ZVS and voltage regulation.