Variable Compensation Inverter Circuit and Related Techniques

A high-frequency inverter architecture is provided that compensates for coupling variations in wireless power transfer (WPT) systems, while adapted to operate at a fixed frequency and maintaining high efficiency. This implementation, termed a variable compensation inverter (VCI), includes a plurality of high-frequency inverters feeding a lossless resonant network, with the inputs of the inverters fed by controllable voltages. By appropriately controlling the input voltages of the individual inverters and their relative phase-shift, the VCI can maintain near-resistive, and slightly but sufficiently inductive, loading of the inverters even as the reactance of the WPT coupler changes; hence, providing compensation while maintaining zero-voltage and near-zero-current switching. The VCI also ensures that the output power of the WPT system is maintained at a fixed level even during coupling variations.