A Series–Parallel-Type Resonant Circuit Wireless Power Transfer System with a Dual Active Bridge DC–DC Converter

This paper presents an equivalent circuit for a non-tight transformer of a series-parallel-type resonant wireless power transfer system. The proposed non-tight transformer circuit is designed as an equation of state with a coupling coefficient parameter and it enables to consider its fluctuation while performing a simulation. In addition, we present a wireless power transfer system with a dual active bridge DC-DC converter. The proposed system synchronises by a phase-locked loop control system and transmits power. In order to confirm performances of the proposed system, we simulated a simulation of the system transfers power using a variable coupling coefficient and a simulation of the system transfers power bi-directionally. In addition, the proposed system adopted pulse width control can improve distortions of AC voltage and current when the dual active bridge DC-DC converter of the proposed system is supplied with different DC voltage sources. From the simulations, we confirm good results and proposed the wireless power transfer with a dual active bridge DC-DC converter that realizes high efficiency power transmission.