A multi-level voltage regulator system/method providing discrete regulation of a DC-DC intermediate bus converter (IBC) output voltage (Vout) is disclosed. The disclosed system/method allows IBC Vout to be regulated in discrete steps during periods where IBC input voltage (Vin) falls below nominal operating values. Rather than shutting down or degrading IBC Vout in an unpredictable non-linear fashion based on IBC input/loading, IBC Vout is regulated in fixed discrete steps, allowing IBC-connected point-of-load (POL) converters to obtain stable power input that is well-defined over IBC Vin. IBC operating parameters may define multi-dimensional operational state spaces of IBC Vout regulation that ensure optimum power flow to attached POLs while maintaining operational stability within the IBC regulator. Instabilities in IBC /POL performance across variations in IBC Vin, load transients, POL loading, and environmental variables may be prevented using Vin voltage step hysteresis.

The present invention relates to an IPT system for wireless power transfer, in particular an IPT system capable of operating at high frequencies. In one aspect there is provided an IPT transmitter comprising: a push-pull resonant converter having a resonant frequency; and configured to operate at a switching frequency below the resonant frequency and dependent on a switching characteristic of a second converter configured to inductively couple to said transmitter.

A converter includes first and second input terminals and first and second output terminals. The converter also includes an output capacitor coupled between the first output terminal and the second output terminal, and a magnetic component having two input terminals and three output terminals. A first output terminal of the magnetic component is coupled through a first electronic switch to the second output terminal of the converter, a second output terminal of the magnetic component is coupled to the first output terminal of the converter, and a third output terminal of the magnetic component is coupled through a second electronic switch to the second output terminal of the electronic converter. In addition, the converter includes a switching stage configured to transfer current pulses from the first input terminal and the second input terminal of the converter to the two input terminals of the magnetic component.