Wireless power transmission device for vehicle and wireless charging method

A vehicle comprising:

• a control system that uses an operation frequency band;
• and
• a wireless power transmission device configured to:
• transmit a wireless power signal to a wireless power reception device, the wireless power signal having a power signal frequency in a transmitter frequency band that is lower than a transmitter resonance frequency of the wireless power transmission device, wherein the transmitter frequency band is different from the operation frequency band of the control system, wherein the transmitter resonance frequency is different from a receiver resonance frequency of the wireless power reception device, and wherein the transmitter resonance frequency is higher than the receiver resonance frequency,
• receive a power control signal from the wireless power reception device, and
• control the power signal frequency based on the power control signal and the transmitter frequency band, wherein the wireless power transmission device is configured to:
• adjust the power signal frequency to a lower frequency when the power control signal indicates a request for a decrease in power and the power signal frequency is lower than the receiver resonance frequency;
• and
• adjust the power signal frequency to a higher frequency when the power control signal indicates a request for an increase in the power and the power signal frequency is lower than the receiver resonance frequency.

A wireless power transmission apparatus, comprising:

• an electric driving unit to supply driving signals;
• a primary coil to generate an electromagnetic field based on the driving signals, the electromagnetic field operable to transmit a wireless power signal to a wireless power reception apparatus, the wireless power signal having a power signal frequency in a transmitter frequency band that is lower than a transmitter resonance frequency of the wireless power transmission apparatus, wherein the transmitter frequency band is different from an operation frequency band of a control system of a vehicle, wherein the transmitter resonance frequency is different from a receiver resonance frequency of the wireless power reception apparatus, and where in the transmitter resonance frequency is higher than the receiver resonance frequency;
• and
• a control unit configured to:
• receive a power control signal from the wireless power reception apparatus, and
• control the power signal frequency of the wireless power signal based on a frequency of the driving signals supplied by the electric driving unit and the transmitter frequency band
• adjust the frequency of the driving signals such that the power signal frequency is decreased when the power control signal indicates a request for a decrease in power and the power signal frequency is lower than the receiver resonance frequency;
• and
• adjust the frequency of the driving signals such that the power signal frequency is increased when the power control signal indicates a request for an increase in the power and the power signal frequency is lower than the receiver resonance frequency.