Wireless power transfer (WPT) technology has two origins of technical background. One is power electronics technology, in which WPT mechanism is considered as a transformer. The other is radio frequency (RF) technology, in which WPT mechanism is considered as a coupling of resonators. The aim of this chapter is to unveil the essence of coupled-resonant WPT by introducing a unified model that enables us to understand power electronics-based WPT and RF-based WPT in the same manner. In the first part of this chapter, unified model of resonance coupling WPT is conducted. This model enables us to understand the mechanism of resonant WPT system from the viewpoint of electric/magnetic coupling and resonance. In the later part, generalized WPT model is conducted. This model represents the whole WPT system including RF inverter and rectifier. By using this model, various kinds of WPT system can be explained from the viewpoint of impedance matching, resonance, and coupling.

Chapter Contents:

• 3.1 Classification of WPT systems
• 3.1.1 Classification of near-field and far-field WPT
• 3.1.2 Classification of resonant WPT
• 3.1.3 Relationship among WPT types
• 3.2 Unified model of resonance coupling WPT
• 3.2.1 Concept of the "coupler"
• 3.2.2 Unified model based on resonance and coupling
• 3.2.3 Application for LC resonator
• 3.2.4 Application for electric field coupling WPT
• 3.2.5 Application for self-resonator
• 3.3 Generalized model of WPT
• 3.3.1 Energy flow in WPT system
• 3.3.2 Generalized model
• 3.3.3 Understanding of coupled-resonator WPT system through generalized model
• 3.3.4 Understanding of coupler-and-matching-circuit WPT system through generalized model
• Acknowledgment
• References

Inspec keywords: invertors; rectifiers; radiofrequency power transmission; inductive power transmission

Other keywords: wireless power transfer technology; resonance coupling WPT; generalized WPT model; RF technology; impedance matching; power electronics technology; electric-magnetic coupling; transformer; radio frequency technology; RF-based WPT; rectifier; RF inverter

Subjects: Power electronics, supply and supervisory circuits; Wireless power transmission