Compensation topologies for wireless power transmission system in medical implant applications: A review

Abstract

This review paper addresses and discusses the challenge of selecting the best topology for a wireless power transmission (WPT) system for a medical implant application in order to improve power transfer efficiency (PTE). WPT systems using inductive and magnetic resonance coupling (MRC) have been introduced in recent years as a convenient and secure alternative to traditional wired charging systems. Compensation topologies are essential in MRC-WPT system to improve the PTE over certain distances. The fundamental topologies comprising series-series (SS), series-parallel (SP), parallel-series (PS), parallel-parallel (PP), and Series-Non resonant secondary (SN) or primary side series (PSS) are all explored and discussed. The theoretical analysis of power transfer efficiency using reflected impedance theory, as well as the selection of the most relevant topology depending on system requirement and application, are studied and addressed. Resonance frequency selection is necessary to identify the compensation capacitor for magnetically coupled WPT system. IEEE and ICNIRP safety regulations and guidelines for biomedical applications are reviewed and addressed.