A voltage source Class-D inverter was exploited for the first time in a test rig for IPT rectifier characterisation independent of the magnetic link. The developed test rig makes the measurement of ac power feasible with commercially available passive voltage and current probes. while providing IPT conditions for the circuits under test. With square wave gate drivers the inverter has a multi-frequency ability and it’s capable of outputting voltage waveforms within the range of 6.78 MHz to 13.56 MHz. Negative bias was essential for eliminating parasitic turn-on from the high dv dt rates. Techniques have been adapted that eliminated the turn-on losses usually observed in Class-D topologies. The implemented inverter was capable of delivering power levels greater than 200 W at the tested rectifiers with peak efficiency greater than 80 %. The gate drive losses occupied 10 % of the total losses. which were dominated by conduction losses. A potential boost in the efficiency of the inverter could come from the replacement of the Si MOSFETs with GaN transistors.
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