Wireless power feeder and wireless power transmission system
AssigneeTDK Corporation
InventorTakashi URANO
Life of this patent
Estimating the term…
Abstract
A feeding coil circuit 120 feeds power by wireless from a feeding coil L2 to a receiving coil L3 based on a magnetic field resonance phenomenon between the feeding coil L2 and receiving coil L3. A transmission power control circuit 200 supplies AC power at a drive frequency to the feeding coil L2 to make the feeding coil L2 feed the AC power to the receiving coil L3. A phase detection circuit 114 measures a phase difference between a current phase of the AC power and a voltage phase thereof. The power transmission control circuit 200 adjusts the drive frequency in accordance with the phase difference. A protection circuit 122 adjusts the phase difference in an increasing direction when the current flowing in the feeding coil L2 increases.
Claims8
A wireless power feeder that feeds power by wireless from a feeding coil to a receiving coil, comprising:
- the feeding coil;
- a power transmission control circuit supplies AC power at a drive frequency to the feeding coil to make the feeding coil feed the AC power to the receiving coil;
- a phase detection circuit that detects a phase difference between a voltage phase of the AC power and a current phase thereof;
- and
- a protection circuit that monitors current flowing in the feeding coil, wherein
- the power transmission control circuit adjusts the drive frequency in accordance with the detected phase difference, and
- the protection circuit adjusts the detected phase difference in an increasing direction when the current flowing in the feeding coil increases.
A wireless power transmission system for feeding power by wireless from a feeding coil to a receiving coil, comprising:
- the feeding coil;
- a power transmission control circuit supplies AC power at a drive frequency to the feeding coil to make the feeding coil feed the AC power to the receiving coil;
- a phase detection circuit that detects a phase difference between a voltage phase of the AC power and a current phase thereof;
- a protection circuit that monitors current flowing in the feeding coil;
- the receiving coil;
- and
- a load circuit that includes a loading coil that is magnetically coupled to the receiving coil to receive the AC power from the receiving coil and a load that receives power from the loading coil, wherein
- the power transmission control circuit adjusts the drive frequency in accordance with the detected phase difference, and
- the protection circuit adjusts the detected phase difference in an increasing direction when the current flowing in the feeding coil increases.
Dependencies are inferred from the claim text.