Wireless power feeder, wireless power receiver, and wireless power transmission system
View Patent ↗A wireless power feeder which performs power feed to a wireless power receiver having a power receive resonance circuit including a power receive coil and a power receive capacitor, this wireless power feeder including: a power feed coil; a resonance current detector; and a control circuit; wherein the power feed coil does not substantially constitute a resonance circuit; the current detector has a detection resonance circuit including a detection coil and a detection capacitor, and detects a resonance current of the power receive resonance circuit; the winding region of the detection coil in the current detector is smaller than the winding region of the power feed coil; and the detection coil in the current detector is disposed such that the central winding axis thereof forms an angle of not less than 80° and not more than 100° with respect to magnetic field vectors generated by the power feed coil.
1. A wireless power feeder which performs power feed by a non-contact method to a wireless power receiver having a power receive resonance circuit including a power receive coil and a power receive capacitor, the wireless power feeder comprising:
a power feed coil;
a resonance current detector which detects a resonance current of the power receive resonance circuit; and
a control circuit which performs power feed from the power feed coil to the power receive coil, on the basis of a magnetic field resonance effect between the power feed coil and the power receive coil, by supplying AC current to the power feed coil, and which associates a frequency of the AC current with a frequency of the resonance current detected by the resonance current detector, wherein
the power feed coil does not substantially constitute a resonance circuit;
the resonance current detector has a detection resonance circuit which includes a detection coil and a detection capacitor, and detects a resonance current of the power receive resonance circuit on the basis of a magnetic field resonance effect between the detection coil and the power receive coil;
a winding region of the detection coil in the resonance current detector is smaller than a winding region of the power feed coil; and
the detection coil in the resonance current detector is disposed such that a central winding axis of the detection coil forms an angle of not less than 80° and not more than 100° with respect to magnetic field vectors generated by the power feed coil.
2. The wireless power feeder according to claim 1 , wherein a length of the winding region of the detection coil in the resonance current detector, which is the length of the winding region of the detection coil in a radial direction of winding of the power feed coil, is not more than 1/10 of the length of the winding region of the power feed coil in the radial direction of winding.
3. The wireless power feeder according to claim 1 , wherein a length of the winding region of the detection coil in the resonance current detector, which is the length of the winding region of the detection coil in a radial direction of winding of the power feed coil, is not more than a length of a coil wire region of the power feed coil in the radial direction of winding.
4. The wireless power feeder according to claim 2 , wherein the detection coil in the resonance current detector is disposed over a coil wire of the power feed coil.
5. The wireless power feeder according to claim 3 , wherein the detection coil in the resonance current detector is disposed over the coil wire of the power feed coil.
6. The wireless power feeder according to claim 1 , wherein the resonance current detector further comprises a detection resistance element for reducing a Q value of the detection resonance circuit.
7. The wireless power feeder according to claim 1 , further comprising a plurality of resonance current detectors and an adder which adds up output signals from a plurality of resonance current detectors; and
the control circuit associates the frequency of the AC current with the frequency of the output signal from the adder.
8. A wireless power feeder which performs power feed by a non-contact method to a wireless power receiver having a power receive resonance circuit including a power receive coil and a power receive capacitor, the wireless power feeder comprising:
a power feed coil;
a resonance current detector which detects a resonance current of the power receive resonance circuit; and
a control circuit which performs power feed from the power feed coil to the power receive coil, on the basis of a magnetic field resonance effect between the power feed coil and the power receive coil, by supplying AC current to the power feed coil, and which associates a frequency of the AC current with a frequency of the resonance current detected by the resonance current detector, wherein
the power feed coil does not substantially constitute a resonance circuit;
the resonance current detector has a magnetic detection element and detects a resonance current of the power receive resonance circuit, on the basis of a magnetic field of the power receive coil;
an outer shape of the magnetic detection element in the resonance current detector is smaller than a winding region of the power feed coil; and
the magnetic detection element in the resonance current detector is disposed such that the magnetic detection direction forms an angle of not less than 80° and not more than 100° with respect to magnetic field vectors generated by the power feed coil.
9. A wireless power receiver which acquires power by a non-contact method from the wireless power feeder according to claim 1 , comprising a power receive resonance circuit including a power receive coil and a power receive capacitor,
the wireless power receiver acquiring power from the power feed coil by the power receive coil on the basis of a magnetic field resonance effect between the power feed coil in the wireless power feeder and the power receive coil in the wireless power receiver.
10. A wireless power transmission system which performs power transmission by a non-contact method between the wireless power feeder according to claim 1 and the wireless power receiver, wherein
power transmission is performed from the power feed coil to the power receive coil on the basis of a magnetic field resonance effect between the power feed coil in the wireless power feeder and the power receive coil in the wireless power receiver.