Modeling of an Electro-Mechanical-Acoustic Contactless Energy Transfer System Based on Multiphysics Networks and Resonant Topologies

This doctoral thesis shows a modeling methodology for an electro-mechanical-acoustic contactless energy transfer system and the analysis and design of its power conversion circuits. Contactless energy transfer systems (CET) are mainly divided into acoustic, inductive, capacitive and optical, which main applications related to biomedical and wireless chargers. The electro-mechanical-acoustic CET system is composed by: an ultrasound transmitter and a receiver based on piezoelectricity, a transfer media and a power conversion circuit. Due to the multi-domains, like as electrical, mechanical and acoustical, a multiphysics scenario is depicted. Modeling of such system requires a well-defined methodology. In this sense, this work presents an analytical multiphysical model based on lumped parameters. The model is based on the geometry and properties of the materials. By means of a decomposition into unit-less parameters scheme, the system is represented by a normalized state-space model. The model leads to solutions that do not depend on design specifications and do not rely on real system parameters. This work shows an equivalent electrical model that can be converted into a piezoelectric transformer model, which is used as part of the resonant tank in resonant topologies. This allows the design of power conversion circuits in order to manage the transfered electrical power. Furthermore, an augmented-order multiphysical model is proposed as an enhancement of the previous models. The models are evaluated for different scenarios and an error analysis is conducted based on the comparison between the experimental response of the physical system and the theoretical results. Resonant topologies are used as representation of the system and the generalized averaged dynamic modeling is performed for the Class-E2 resonant converter. A practical demonstrator including the piezoelectric ultra-sound transmitter and receiver, solid transfer media, and the power conversion circuitry was assembled in order to evaluate the feasibility of the system for practical applications.