Wireless power transmission appratus and control method thereof

A wireless power transmission apparatus, comprising:

• a transmitting unit, comprising an inverter circuit, a first compensation circuit and a transmitting coil, the first compensation circuit being coupled between the inverter circuit and the transmitting coil;
• a receiving unit, comprising a receiving coil, a second compensation circuit and a rectifier circuit, the second compensation circuit being coupled between the receiving coil and the rectifier circuit;
• a power regulation circuit, configured to regulate an output signal of the wireless power transmission apparatus;
• and
• a control unit, coupled to the inverter circuit and the power regulation circuit respectively, and configured to:
• acquire a voltage-and-current phase difference of the transmitting unit, a detection signal, and a power detection value of the wireless power transmission apparatus;
• control an operating frequency of the inverter circuit according to the voltage-and-current phase difference and a preset phase difference in such a manner that the voltage-and-current phase difference is equal to the preset phase difference, and generate a power derating signal according to the detection signal, and control, according to the power derating signal, the power detection value and a power reference signal, the power regulation circuit to regulate the output signal;
• wherein the first compensation circuit, the transmitting coil, the receiving coil and the second compensation circuit form a resonant network, and parameters of an inductance component and a capacitance component in the resonant network are adjusted, so that the resonant network has three resonant frequency points which are a first resonant frequency point, a second resonant frequency point and a third resonant frequency point, wherein the second resonant frequency is higher than the first resonant frequency, the first resonant frequency is higher than the third resonant frequency point;
• and
• the operating frequency is higher than the second resonant frequency;
• or, the operating frequency is equal to the second resonant frequency;
• or, the operating frequency is lower than the second resonant frequency and higher than the first resonant frequency.