Wireless power transmission apparatus
A wireless power transmission apparatus according to an embodiment of the present invention includes a resonance-type coil unit, an induction-type coil unit, and a loss suppression unit including a serial resonant circuit connected to both ends of the induction-type coil unit, wherein the loss suppression unit resonates at a first frequency for driving the resonance-type coil unit. A wireless power transmission apparatus according to another embodiment of the present invention includes a resonance-type coil unit, an induction-type coil unit, and a switch element connected to both ends of the induction-type coil unit, wherein the switch element is turned on or off when power is transmitted by either of the resonance-type coil unit or the induction-type coil unit.
1. A wireless power transmission apparatus comprising:
a resonance-type coil unit;
an induction-type coil unit; and
a loss suppression unit comprising a serial resonant circuit connected to both ends of the induction-type coil unit,
wherein the loss suppression unit resonates at a first frequency for driving the resonance-type coil unit.
2. The wireless power transmission apparatus of claim 1 , wherein the serial resonant circuit comprises at least one capacitor and at least one inductor.
3. The wireless power transmission apparatus of claim 1 , wherein the loss suppression unit has an impedance magnitude equal to or greater than an impedance magnitude preset at a second frequency for driving the induction-type coil unit.
4. The wireless power transmission apparatus of claim 3 , further comprising:
a first DC/AC conversion unit configured to convert a first DC signal and transfer an AC signal having the first frequency to the resonance-type coil unit; and
a second DC/AC conversion unit configured to convert a second DC signal and transfer an AC signal having the second frequency to the induction-type coil unit.
5. The wireless power transmission apparatus of claim 4 , further comprising a control unit configured to control operations of the first and second DC/AC conversion units,
wherein the control unit enables the first DC/AC conversion unit and disables the second DC/AC conversion unit so that the first DC/AC conversion unit is controlled to transfer the AC signal having the first frequency to the resonance-type coil unit, and enables the second DC/AC conversion unit and disables the first DC/AC conversion unit so that the second DC/AC conversion unit is controlled to transfer the AC signal having the second frequency to the induction-type coil unit.
6. The wireless power transmission apparatus of claim 4 , further comprising an AC/DC conversion unit configured to receive an AC signal and supply the first and second DC signals to the first and second DC/AC conversion units,
wherein the first DC/AC conversion unit comprises:
a first high-frequency filter unit connected between the AC/DC conversion unit and a first node;
a second high-frequency filter unit connected between the AC/DC conversion unit and a second node;
a first switch connected between the first node and a third node; and
a second switch connected between the second node and the third node,
wherein the resonance-type coil unit is connected between the first node and the second node.
7. The wireless power transmission apparatus of claim 4 , further comprising an AC/DC conversion unit configured to receive an AC signal and supply the first and second DC signals to the first and second DC/AC conversion units,
wherein the second DC/AC conversion unit comprises:
a first switch connected between the AC/DC conversion unit and a first node;
a second switch connected between the first node and a third node;
a third switch connected between the AC/DC conversion unit and a second node; and
a fourth switch connected between the second node and the third node,
wherein the induction-type coil unit is connected between the first node and the second node.
8. The wireless power transmission apparatus of claim 3 , wherein the first frequency is about 6.78 MHz, and the second frequency is about 125 KHz.
9. The wireless power transmission apparatus of claim 1 , wherein the loss suppression unit comprises a variable capacitor and a variable inductor connected in series to each other.
10. The wireless power transmission apparatus of claim 9 , wherein, when the first frequency is varied, at least one of a capacitance of the variable capacitor and an inductance of the variable inductor is varied.
11. A wireless power transmission apparatus comprising:
a resonance-type coil unit;
an induction-type coil unit; and
a switch element connected to both ends of the induction-type coil unit,
wherein the switch element is turned on or off when power is transmitted by either of the resonance-type coil unit or the induction-type coil unit.
12. The wireless power transmission apparatus of claim 11 , wherein the switch element is turned on when power is transmitted by the resonance-type coil unit.
13. The wireless power transmission apparatus of claim 11 , wherein the switch element is turned off when power is transmitted by the induction-type coil unit.
14. The wireless power transmission apparatus of claim 13 , further comprising:
a first DC/AC conversion unit configured to convert a first DC signal and transfer an AC signal having a first frequency to the resonance-type coil unit; and
a second DC/AC conversion unit configured to convert a second DC signal and transfer an AC signal having a second frequency to the induction-type coil unit.
15. The wireless power transmission apparatus of claim 14 , further comprising a control unit configured to control operations of the first and second DC/AC conversion units and an operation of the switch element,
wherein the control unit enables the first DC/AC conversion unit and disables the second DC/AC conversion unit so that the first DC/AC conversion unit is controlled to transfer the AC signal having the first frequency to the resonance-type coil unit, and
the control unit turns on the switch element.
16. The wireless power transmission apparatus of claim 14 , further comprising a control unit configured to control operations of the first and second DC/AC conversion units,
wherein the control unit enables the second DC/AC conversion unit and disables the first DC/AC conversion unit so that the second DC/AC conversion unit is controlled to transfer the AC signal having the second frequency to the induction-type coil unit, and
the control unit turns off the switch element.
17. The wireless power transmission apparatus of claim 14 , further comprising an AC/DC conversion unit configured to receive an AC signal and supply the first and second DC signals to the first and second DC/AC conversion units,
wherein the first DC/AC conversion unit comprises:
a first high-frequency filter unit connected between the AC/DC conversion unit and a first node;
a second high-frequency filter unit connected between the AC/DC conversion unit and a second node;
a first switch connected between the first node and a third node; and
a second switch connected between the second node and the third node,
wherein the resonance-type coil unit is connected between the first node and the second node.
18. The wireless power transmission apparatus of claim 14 , further comprising an AC/DC conversion unit configured to receive an AC signal and supply the first and second DC signals to the first and second DC/AC conversion units,
wherein the second DC/AC conversion unit comprises:
a first switch connected between the AC/DC conversion unit and a first node;
a second switch connected between the first node and a third node;
a third switch connected between the AC/DC conversion unit and a second node; and
a fourth switch connected between the second node and the third node,
wherein the induction-type coil unit is connected between the first node and the second node.
19. The wireless power transmission apparatus of claim 11 , wherein, when the resonance-type coil unit is driven, an AC signal having a frequency of about 6.78 MHz is supplied to the resonance-type coil unit.
20. The wireless power transmission apparatus of claim 11 , wherein, when the induction-type coil unit is driven, an AC signal having a frequency of about 125 KHz is supplied to the induction-type coil unit.