Apparatus and method for receiving wireless power, and system for transmitting wireless power
The wireless power reception apparatus includes: a duty controller configured to calculate an amount of current of a transmission coil required for the wireless power transmission apparatus and control a duty cycle by using at least one of distance information between the wireless power transmission apparatus and the wireless power reception apparatus or load current information; a power converter configured to convert an effective load resistance according to the duty cycle; a wireless data transmitter configured to transmit a signal that requires a control of the calculated amount of current of the transmission coil to the wireless power transmission apparatus; and a reception resonator configured to receive a power according to the amount of current of the transmission coil controlled by the signal that requires a control of the amount of current of the transmission coil from the wireless power transmission apparatus.
1. A wireless power reception apparatus which receives a power from a wireless power transmission apparatus, the wireless power reception apparatus comprising:
a duty controller configured to calculate an amount of current of a transmission coil required for the wireless power transmission apparatus and control a duty cycle by using at least one of distance information between the wireless power transmission apparatus and the wireless power reception apparatus or load current information for an actual load resistance;
a power converter configured to convert the actual load resistance into an effective load resistance according to the duty cycle;
a wireless data transmitter configured to transmit a signal that requires a control of the calculated amount of current of the transmission coil to the wireless power transmission apparatus; and
a reception resonator configured to receive a power according to the amount of current of the transmission coil controlled by the signal that requires a control of the amount of current of the transmission coil from the wireless power transmission apparatus,
wherein the duty controller controls the duty cycle of the power converter in response to the power received according to the amount of current of the transmission coil controlled by the signal that requires a control of the amount of current of the transmission coil,
wherein the wireless data transmitter transmits a signal requesting to increase the amount of current of the transmission coil to the wireless power transmission apparatus, and the duty controller controls the power converter to decrease the effective load resistance when a distance between the wireless power transmission apparatus and the wireless power reception apparatus increases,
wherein the wireless data transmitter transmits a signal requesting to decrease the amount of current of the transmission coil to the wireless power transmission apparatus and the duty controller controls the power converter to decrease the effective load resistance, when a load resistance of the wireless power reception apparatus increases.
2. The wireless power reception apparatus of claim 1 , further comprising a rectifier configured to rectify and output the current outputted from the reception resonator.
3. The wireless power reception apparatus of claim 2 , wherein the power converter is located between the reception resonator and the rectifier.
4. The wireless power reception apparatus of claim 2 , wherein the power converter is located in an output terminal of the rectifier.
5. The wireless power reception apparatus of claim 1 , wherein the duty controller determines a distance change between the wireless power transmission apparatus and the wireless power reception apparatus increases by using a PWM duty cycle of the power converter.
6. The wireless power reception apparatus of claim 1 , wherein the wireless data transmitter periodically modulates and transmits the duty cycle of the power converter at a frequency band lower than a preset reference, when transmitting the signal for a control of the amount of current of the transmission coil to the wireless power transmission apparatus.
7. A wireless power transmission system comprising:
a wireless power transmission apparatus configured to transmit a power according to an amount of current of a transmission coil; and
a wireless power reception apparatus configured to receive the power transmitted from the wireless power transmission apparatus,
wherein, when the wireless power reception apparatus transmits a signal for controlling the amount of current of a transmission coil of the wireless power transmission apparatus to the wireless power transmission apparatus according to a distance change between the wireless power transmission apparatus and the wireless power reception apparatus or a load resistance change, the wireless power transmission apparatus adjusts the amount of current of a transmission coil according to the signal for controlling the amount of current of a transmission coil and transmits a power, and the wireless power reception apparatus adjusts a duty cycle of a power converter in response to the adjusted amount of current of a transmission coil,
wherein the wireless power transmission apparatus controls to increase the amount of current of the transmission coil and to decrease the effective load resistance when a distance between the wireless power transmission apparatus and the wireless power reception apparatus increases,
wherein the wireless power transmission apparatus controls to decrease the amount of current of the transmission coil and to decrease the effective load resistance, when a load resistance of the wireless power reception apparatus increases.
8. A method of receiving a power by a wireless power reception apparatus comprising a reception resonator and a power converter from a wireless power transmission apparatus, the method comprising:
transmitting a signal for controlling an amount of current of a transmission coil of the wireless power transmission apparatus to the wireless power transmission apparatus according to a distance change between the wireless power transmission apparatus and the wireless power reception apparatus or a load resistance change;
receiving a power which is outputted after the amount of current of a transmission coil is adjusted from the wireless power transmission apparatus;
adjusting an effective load resistance conversion ratio of the power converter in response to the received power; and
converting an actual load resistance into an effective load resistance according to the effective load resistance conversion ratio,
wherein transmitting a signal for controlling an amount of current of a transmission coil of the wireless power transmission apparatus to the wireless power transmission apparatus comprises transmitting a signal requesting to increase the amount of current of the transmission coil to the wireless power transmission apparatus when a distance between the wireless power transmission apparatus and the wireless power reception apparatus increases,
wherein transmitting a signal for controlling an amount of current of a transmission coil of the wireless power transmission apparatus to the wireless power transmission apparatus comprises transmitting a signal requesting to decrease the amount of current of the transmission coil to the wireless power transmission apparatus, when a load resistance of the wireless power reception apparatus increases.
9. The method of claim 8 , wherein adjusting an effective load resistance conversion ratio of the power converter in response to the received power comprises increasing the effective load resistance conversion ratio, when the amount of current of the transmission coil is decreased.
10. The method of claim 9 , wherein adjusting an effective load resistance conversion ratio of the power converter in response to the received power comprises decreasing the effective load resistance conversion ratio, when the amount of current of the transmission coil is increased.