Self-tuning resonant power transfer systems

The wireless power transfer system of 1, wherein resonator tuning between the receiver and transmit resonators is optimized to keep a voltage gain within a specified range as the coupling coefficient varies.

The wireless power transfer system of 1, wherein resonator tuning between the receiver and transmit resonators is optimized to maximize efficiency over a given range.

The wireless power transfer system of 1, wherein resonator tuning between the receiver and transmit resonators is optimized to achieve a minimum amount of power transferred for a given source voltage.

A method of controlling a wireless power transfer system, comprising the steps of:

• transmitting wireless power from a transmit resonator to a receive resonator;
• and
• allowing resonant frequencies of the system to move towards an operating frequency of the system as a coupling coefficient between the transmit and receive resonators becomes smaller.

A method of controlling a wireless power transfer system, comprising the steps of:

• transmitting wireless power from a transmit resonator to a receive resonator;
• and
• controlling a current delivered to a DC load connected to the receive resonator by comparing an actual current at the DC load to a current requested by the DC load and adjusting an angle or a magnitude of a voltage at the DC load to match the requested current.

A wireless power transfer system, comprising:

• a transmit resonator coupled to a voltage source;
• and
• a receive resonator inductively coupled to the transmit resonator and connected to a load with a rectifier circuit comprising a plurality of FETs, wherein the rectifier circuit acts as a controlled voltage source and is configured to tune resonant frequencies between the transmit resonator and the receive resonator.