Multi-frequency Class-D inverter for rectifier characterisation in high frequency inductive power transfer systems

摘要

This paper presents the development and utilisation of a voltage source multi-frequency Class-D inverter in a cost-effective test rig for rectifiers in 6.78 MHz to 13.56 MHz inductive power transfer (IPT) systems without the need of the magnetic link. Apart from the inverter, the rig compromises a tuned receiving (Rx) coil of the IPT system and a rectifier under test. With the inverter emulating a magnetically induced voltage in an Rx coil, rectifiers experience IPT conditions while they are isolated from the rest of the system. Therefore, they are accurately analysed with commercially available instruments, without affecting other parts of the IPT system. The Class-D inverter was implemented with Si MOSFETs and is capable of delivering power greater than 200 W with efficiencies higher than 80 %.