A magnetic coupled resonant wireless power transfer method

Abstract

The application aims to provide a magnetic coupling resonance type wireless power transmission method, which utilizes a wireless charging device with the following structure: the wireless charging device comprises a transmitting coil moving platform, a shell, a receiving coil and a SEPIC circuit; the transmitting coil moving platform comprises a base, a vertical moving mechanism, a horizontal moving mechanism, a horizontal moving table, a horizontal steering mechanism, an angle steering mechanism, a coil mounting platform, a coil support, a transmitting coil, a controller, a direct current voltage source, a high-frequency full-bridge inverter module, a current sensor and a receiving end; the wireless charging device is used to adjust the position of the transmitting coil so that it is located at the optimal position corresponding to the receiving coil. The application adds a mechanical control structure to the transmitting coil and a control algorithm to overcome the problem of reduced system transmission efficiency caused by the positional and angular deviation between the transmitting coil and the receiving end. The SEPIC circuit of the receiving end is controlled by the disturbance observation method to realize the maximum power output of the system.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and more specifically to a magnetically coupled resonant wireless power transmission method. Background Technology

[0002] Resonant wireless charging allows devices to be charged without contact. However, the transmitting coil of a resonant wireless charger is usually fixed in one place, and the receiving device is placed arbitrarily. Each time it is charged, there is a high risk of positional deviation. This positional deviation may cause the system to operate in an over-coupled or under-coupled state, which will greatly affect the transmission efficiency of the system. Summary of the Invention

[0003] This invention aims to provide a magnetically coupled resonant wireless power transfer method. This method utilizes a uniquely structured wireless charging device combined with a particle swarm optimization (PI) algorithm to achieve frequency locking of the current system, thereby suppressing frequency splitting and undercoupling, and improving transmission efficiency. Furthermore, at the receiving end, a perturbation-observation control algorithm is incorporated using a SEPIC circuit, enabling the system to output maximum power.

[0004] The technical solution of the present invention is as follows: The magnetically coupled resonant wireless power transfer method described above utilizes a wireless charging device with the following structure: The wireless charging device includes a transmitting coil moving platform and a receiving coil; The transmitting coil moving platform includes a base, a vertical moving mechanism, a horizontal moving mechanism, a horizontal moving stage, a horizontal turning mechanism, an angle turning mechanism, a coil mounting platform, a coil support, a transmitting coil, a controller, a DC voltage source, a high-frequency full-bridge inverter module, a first communication module, and a first power detection module. The vertical moving mechanism is mounted on the base, and the horizontal moving mechanism is mounted on the vertical moving mechanism, enabling it to rise and fall under the drive of the vertical moving mechanism; the horizontal moving platform is mounted on the horizontal moving mechanism, enabling it to move horizontally under the drive of the horizontal moving mechanism; the horizontal turning mechanism is mounted on the top surface of the horizontal moving platform; the angle turning mechanism is mounted on the horizontal turning mechanism, enabling it to rotate under the drive of the horizontal turning mechanism; the coil support is mounted on the angle turning mechanism, and the transmitting coil is mounted on the coil support.

[0005] The controller, DC voltage source, and high-frequency full-bridge inverter module are mounted on the base; the DC voltage source supplies power to each power-consuming module, and the DC voltage source supplies power to the transmitting coil through the high-frequency full-bridge inverter module; the controller controls the operation of each module. The first communication module and the first power detection module are mounted on the coil support and are electrically connected to the controller. Its transmission method includes the following steps: A. Place the receiving end above the transmitting coil. The controller starts the first communication module and the first power detection module. The first power detection module detects the power of the transmitting coil and transmits power, voltage, and current signals to the controller through the first communication module. The controller controls the horizontal movement mechanism to drive the transmitting coil to move 1cm in each of the four horizontal directions (front, back, left, and right). After moving 1cm in each direction, it returns to its original position and then moves to the next direction. The controller compares the power of the transmitting coil after moving in each direction and controls the horizontal movement mechanism to drive the transmitting coil to move 1cm to the position with the highest power. This new position is used as the starting position for the next set of four horizontal directions. This process is repeated until the power is not as high as the power at the previous position when moving to the next direction. Then, the coil returns to the previous position and the horizontal movement ends. B. The controller controls the angle steering mechanism to drive the transmitting coil to rotate in the vertical plane, adjusting the angle between the transmitting coil and the horizontal plane. The angle of the transmitting coil deviates by 1 degree. Then, the controller controls the horizontal steering mechanism to drive the transmitting coil to rotate 360 ​​degrees in the horizontal plane, and detects the power during this process. This process is repeated until the transmitting coil forms a 45-degree angle with the horizontal direction. The controller, based on the angle position corresponding to the maximum power, drives the transmitting coil to reach that position by controlling the angle steering mechanism and the horizontal steering mechanism. C. The controller controls the vertical moving mechanism to drive the transmitting coil to rise 1cm. Based on the power obtained from the first power detection module and the second power detection module, the controller calculates the efficiency at this position, restores the original position, and then descends 1cm. The controller calculates the efficiency at this position based on the power obtained from the first power detection module and the second power detection module, compares the efficiency of the upward and downward moving positions, and controls the vertical moving mechanism to drive the transmitting coil to move 1cm in the direction with greater efficiency. The moved position is used as the origin for the next set of upward and downward movements. This process is repeated until the transmitting coil reaches the position with the best efficiency.

[0006] It also includes the following steps: D. The current and voltage waveforms of the current transmitting coil are obtained through the current phase sampling module and the voltage phase sampling module, and input to the controller. The controller compares the phases of the voltage and current signals to obtain an error signal. The error signal is controlled using a particle swarm optimization (PID) algorithm to ensure that the phase difference between the voltage and current is zero. A voltage-controlled oscillator is implemented internally by the controller, generating a PWM wave to drive the high-frequency full-bridge inverter module, achieving system resonance. Both the voltage phase acquisition module and the current phase acquisition module are mounted on the coil support.

[0007] The receiving end is equipped with a second communication module and a second power detection module; the second power detection module detects the power of the receiving coil load and transmits data to the controller through the second communication module; Throughout step AD, the controller sets the sampling time interval and uses the second power detection module to detect the load power and load voltage across the load terminals of the receiving coil. The controller then uses the read load power and load voltage to calculate and control the SEPIC circuit using the perturbation-observation algorithm. The control process is as follows: The controller compares the power at the receiving coil load terminal of the previous moment with the power at the current moment. If the current load power is greater than the previous load power, it compares the current load voltage with the previous load voltage. If the current load voltage is greater than the previous load voltage, the controller increases the duty cycle by 1%. If the current voltage is less than or equal to the previous voltage, the controller decreases the duty cycle by 1%. The same process continues until the current load power equals the previous load power, at which point the duty cycle reaches its optimal value, achieving impedance matching and maximizing power output. The controller adjusts the duty cycle by controlling the switching of the MOSFETs in the SEPIC circuit. Repeat the above process at regular intervals to ensure that the wireless charging device operates at maximum power output.

[0008] The efficiency information calculation formula in step C is as follows: (1) in, AC voltage source The current in the circuit containing the transmitting coil. The detuning factor, ; Coupling factor j is the imaginary part; , The power supply impedance is... The impedance of the transmitting coil (14) is... The impedance of the receiving end. The impedance of the load; The frequency generated by the high-frequency full-bridge inverter module; is the inherent resonant frequency of the resonant circuit; M is the mutual inductance between the transmitting coil and the receiving coil.

[0009] The vertical moving mechanism includes a vertical stepper motor, a vertical transmission mechanism, screw a, and screw b; The horizontal moving mechanism includes a horizontal stepper motor a, a horizontal stepper motor b, a horizontal rod a, a horizontal rod b, a horizontal sliding plate a, a horizontal support plate a, a horizontal support plate b, a horizontal sliding plate b, a screw c, and a screw d; The lower end of one of the screws, a and b, is connected to the output shaft of a vertical stepper motor, which is mounted on the top surface of the base. The lower end of the other screw is mounted on the top surface of the base via a bearing. Screws a and b are located on the left and right sides of the top surface of the base, respectively. The output shaft of the vertical stepper motor is vertically upward, and both screws a and b are vertically positioned. Screws a and b are connected by a vertical transmission mechanism. The rear end of the horizontal stepper motor a is provided with a vertical drive thread through hole a, and it is installed on the screw a through the vertical drive thread through hole a. The rear end of the horizontal stepper motor b is provided with a vertical drive thread through hole b, and it is installed on the screw b through the vertical drive thread through hole b. The output shaft of the horizontal stepper motor a is horizontally positioned to the right, and a screw c with the same axial direction is mounted on it. A horizontal support plate b is mounted on the right side wall of the horizontal stepper motor a, extending to the right and perpendicular to the screw c. The output shaft of the horizontal stepper motor b is horizontally positioned to the rear, and a screw d with the same axial direction is mounted on it. A horizontal support plate a is mounted on the left side wall of the horizontal stepper motor b, extending to the left and perpendicular to the screw d. The screw d and screw c are perpendicular. A horizontal sliding plate a is provided on the right side of the horizontal rod a, and the horizontal sliding plate a is perpendicular to the horizontal rod a; a horizontal sliding plate b is provided on the left side of the horizontal rod b, and the horizontal sliding plate b is perpendicular to the horizontal rod b; the horizontal sliding plate a is perpendicular to the horizontal sliding plate b. The side of the horizontal moving platform is provided with sliding through holes a and b corresponding to the horizontal sliding plate a and the horizontal sliding plate b, respectively, and the sliding through holes a and b are spaced apart in the vertical direction; the horizontal sliding plate a and the horizontal sliding plate b are respectively inserted into the sliding through holes a and the sliding through holes b. The horizontal support plate a has a horizontal groove a along its longitudinal direction on the left side wall, and the end of the horizontal slide plate a extends into the horizontal groove a and can slide along the horizontal groove. The horizontal support plate b has a horizontal groove b along its longitudinal direction on the left side wall, and the end of the horizontal slide plate b extends into the horizontal groove b and can slide along the horizontal groove. The horizontal steering mechanism is a horizontal steering stepper motor, and the angle steering mechanism is an angle steering stepper motor; the horizontal steering stepper motor is installed on the top surface of the horizontal moving platform; the output shaft of the horizontal steering stepper motor is vertically upward, and the angle steering stepper motor is installed on it; the output shaft of the angle steering stepper motor is horizontal, and a swing rod is installed on it; the upper end of the swing rod is provided with a coil bracket, and the transmitting coil is located on the coil bracket.

[0010] The vertical transmission mechanism includes sleeve a, sleeve b, transmission shaft, bevel gear a, bevel gear b, and bevel gear c; bevel gear a and bevel gear b are respectively located at the lower part of screw a and screw b; The sleeves a and b are mounted on the base; the sleeve a covers the vertical stepper motor and the lower part of the screw a, the top of the sleeve a is provided with a gear through hole that allows the bevel gear a to pass through, the bottom surface of the sleeve a is an open structure, the side wall of the sleeve a is provided with a limiting shaft hole a and an inverted L-shaped through hole a, the upper part of the limiting shaft hole a is connected to the upper front side of the L-shaped through hole a, and the lower end of the L-shaped through hole a is located at the lower end face of the sleeve a, forming a rotating shaft channel; The sleeve b covers the bearing and the lower part of the screw b. The top of the sleeve b is provided with a through hole that allows the bevel gear b to pass through. The bottom surface of the sleeve b is an open structure. The side wall of the sleeve b is provided with a limiting shaft hole b and an inverted L-shaped through hole b. The upper part of the limiting shaft hole b is connected to the upper rear side of the L-shaped through hole b. The lower end of the L-shaped through hole b is located at the lower end face of the sleeve b, forming a rotating shaft channel. The two sides of the drive shaft are respectively placed in the limiting shaft hole a and the limiting shaft hole b, and the two ends of the drive shaft extend into the sleeve a and the sleeve b respectively. The two ends of the drive shaft are respectively provided with bevel gear c, and the bevel gear c at both ends of the drive shaft meshes with bevel gear a and bevel gear b respectively. The base has mounting rings with internal threads on its left and right sides respectively. The lower ends of the outer circular surfaces of sleeves a and b are respectively provided with external threads corresponding to the internal threads. Sleeves a and b are installed on the mounting rings on the left and right sides of the base through threaded engagement.

[0011] The voltage phase acquisition module is a voltage sampling circuit composed of a chip and resistors and capacitors, and the current phase acquisition module is a current sampling circuit composed of a chip and resistors and capacitors.

[0012] The present invention also provides a wireless power transmission device to realize the above-mentioned magnetic coupling resonant wireless power transmission method, and further includes a housing, wherein the transmitting coil moving platform is disposed inside the housing, and the top surface of the housing is used to place the wireless charging receiver.

[0013] The horizontal stepper motor model can be 20HD1401.

[0014] The vertical stepper motor model can be 28HD1401.

[0015] The horizontal steering stepper motor model can be 20HD3401.

[0016] The angular steering stepper motor model can be 20HD3401.

[0017] The voltage phase acquisition module can use the NE5532P chip.

[0018] The current phase acquisition module can use the CC6920 chip.

[0019] The phase-locked loop module can use the CD4046 chip.

[0020] The driver module can use an IR2110 chip.

[0021] The controller can be an STM-32 microprocessor.

[0022] This invention utilizes a wireless charging device with a unique structure, combined with a particle swarm optimization (PI) algorithm, to achieve frequency locking of the current system, thereby suppressing frequency splitting and undercoupling, and improving system transmission efficiency. Furthermore, at the receiving end, a perturbation-observation algorithm is used to control the SEPIC circuit, matching impedance to enable the system to output maximum power.

[0023] The wireless charging device of this invention has a scientifically sound and reasonable structural design. Through the combined design of vertical stepper motor a, vertical stepper motor b, horizontal stepper motor a, horizontal stepper motor b, horizontal rod a, horizontal rod b, horizontal slide plate a, horizontal slide plate b, horizontal moving platform, horizontal steering stepper motor, and angle steering stepper motor, and with the control of the controller, the transmission efficiency of the magnetically coupled resonant wireless power transmission system in the undercoupled working region caused by the misalignment between coils can be improved. Furthermore, a disturbance observation control algorithm is added at the receiving end to maximize the transmission power of the system.

[0024] This invention controls the transmitting coil to change its position in various ways within a large plane, thus enabling effective power supply to electrical equipment in all directions within this plane, thereby improving ease of use. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the transmitting coil moving platform in an embodiment; Figure 2 This is a schematic diagram of the vertical transmission mechanism in the embodiment; Figure 3 A comparison chart of efficiency at the same frequency for different mutual inductance values; Figure 4 State diagrams for different coupling levels of the system; Figure 5 This is a diagram of the undercoupled state of the system. Figure 6 This is a schematic diagram of the perturbation-observation control algorithm process; The names and numbers of the parts in the diagram are as follows: 1-Base, 2-Vertical stepper motor, 3-Vertical transmission mechanism, 4-Horizontal stepper motor a, 5-Horizontal stepper motor b, 6-Horizontal rod a, 7-Horizontal rod b, 8-Horizontal slide plate a, 9-Horizontal slide plate b, 10-Horizontal moving stage, 11-Horizontal steering stepper motor, 12-Angle steering stepper motor, 13-Coil bracket, 14-Transmitting coil, 15-Screw a, 16-Vertical transmission threaded through hole a, 17-Screw b, 18-Vertical transmission threaded through hole b, 19-Screw c, 20-Screw d, 21-Horizontal transmission threaded through hole a, 22-Horizontal transmission threaded through hole b, 23-Sliding through hole a, 24-Sliding through hole b, 25-Swing rod, 26-Sleeve a, 27-Slot a, 28-Slot b, 29-Drive shaft, 30-Sleeve b, 31-Bevel gear a, 32-Bevel gear b, 33-Bevel gear c, 34-Limiting shaft hole a, 35-L-shaped through hole a, 36-Limiting shaft hole b, 37-L-shaped through hole b, 38-Mounting ring, 39-Gear through hole, 40-Mounting bearing. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Example 1 The magnetically coupled resonant wireless power transfer method described above utilizes a wireless charging device with the following structure: The wireless charging device includes a transmitting coil moving platform and a housing; like Figure 1 , Figure 2 As shown, The magnetically coupled resonant wireless power transfer method described above utilizes a wireless charging device with the following structure: The wireless charging device includes a transmitting coil moving platform and a receiving coil; The transmitting coil moving platform includes a base 1, a vertical moving mechanism, a horizontal moving mechanism, a horizontal moving stage 10, a horizontal turning mechanism, an angle turning mechanism, a coil mounting platform 26, a coil support 13, a transmitting coil 14, a controller, a DC voltage source, a high-frequency full-bridge inverter module, a first communication module, and a first power detection module. The vertical moving mechanism is located on the base 1, and the horizontal moving mechanism is located on the vertical moving mechanism and can be raised and lowered under the drive of the vertical moving mechanism; the horizontal moving platform 10 is located on the horizontal moving mechanism and can move horizontally under the drive of the horizontal moving mechanism; the horizontal turning mechanism is located on the top surface of the horizontal moving platform 10; the angle turning mechanism is located on the horizontal turning mechanism and can rotate under the drive of the horizontal turning mechanism; the coil support 13 is located on the angle turning mechanism, and the transmitting coil (14) is located on the coil support 13.

[0028] The controller, DC voltage source, and high-frequency full-bridge inverter module are mounted on the base 1; the DC voltage source supplies power to each power-consuming module, and the DC voltage source supplies power to the transmitting coil 14 through the high-frequency full-bridge inverter module; the controller controls the operation of each module. The first communication module and the first power detection module are mounted on the coil bracket 13 and are electrically connected to the controller. Its transmission method includes the following steps: A. Place the receiving end above the transmitting coil. The controller controls the first communication module and the first power detection module to start working. The first power detection module detects the power of the transmitting coil 14 and transmits power, voltage, and current signals to the controller through the first communication module. The controller controls the horizontal movement mechanism to drive the transmitting coil to move 1cm in each of the four horizontal directions (front, back, left, and right). After moving 1cm in each direction, it returns to its original position and then moves to the next direction. The controller compares the power of the transmitting coil 14 after moving in each direction and controls the horizontal movement mechanism to drive the transmitting coil to move 1cm to the position with the highest power. The position after the movement is taken as the original position for the next set of four directions. This process is repeated until the power is not as high as the power at the previous position when moving to the next direction. Then, it returns to the previous position and the horizontal movement stops. At this point, it can be considered that the transmitting coil 14 and the receiving coil of the wireless charging receiver are aligned in the vertical direction. B. The controller controls the angle steering mechanism to drive the transmitting coil to rotate in the vertical plane, adjusting the angle between the transmitting coil and the horizontal plane. The angle of the transmitting coil deviates by 1 degree. Then, the controller controls the horizontal steering mechanism to drive the transmitting coil to rotate 360 ​​degrees in the horizontal plane, and detects the power during this process. This process is repeated until the transmitting coil forms a 45-degree angle with the horizontal direction. The controller, based on the angle position corresponding to the maximum power, drives the transmitting coil to reach that position by controlling the angle steering mechanism and the horizontal steering mechanism. C. The controller controls the vertical moving mechanism to drive the transmitting coil to rise 1cm. Based on the power obtained from the first power detection module and the second power detection module, the controller calculates the efficiency at this position, restores the original position, and then descends 1cm. The controller calculates the efficiency at this position based on the power obtained from the first power detection module and the second power detection module, compares the efficiency of the upward and downward moving positions, and controls the vertical moving mechanism to drive the transmitting coil to move 1cm in the direction with greater efficiency. The moved position is used as the origin for the next set of upward and downward movements. This process is repeated until the transmitting coil reaches the position with the best efficiency.

[0029] It also includes the following steps: D. Obtain the current and voltage waveforms of the current transmitting coil 14 through the current phase sampling module and the voltage phase sampling module, and input them to the controller; the controller compares the phases of the voltage and current signals to obtain the error signal, and uses the particle swarm PID algorithm to control the error signal so that the voltage and current phase difference is 0. After zero comparison, a PWM wave is generated to drive the high-frequency full-bridge inverter module to realize the resonance of the system. The voltage phase acquisition module and the current phase acquisition module are both mounted on the coil bracket 13.

[0030] The receiving end is equipped with a second communication module and a second power detection module; the second power detection module detects the power of the receiving coil load and transmits data to the controller through the second communication module; Throughout step AD, the controller sets the sampling time interval; in this embodiment, it is set to 100 samples per second. The second power detection module detects the load power and load voltage at both ends of the receiving coil load. The controller calculates the load power and load voltage read in using the perturbation-observation algorithm and controls the SEPIC circuit accordingly. The control process is as follows: The controller compares the power at the receiving coil load terminal of the previous moment with the power at the current moment. If the current load power is greater than the previous load power, it compares the current load voltage with the previous load voltage. If the current load voltage is greater than the previous load voltage, the controller increases the duty cycle by 1%. If the current voltage is less than or equal to the previous voltage, the controller decreases the duty cycle by 1%. The same process continues until the current load power equals the previous load power, at which point the duty cycle reaches its optimal value, achieving impedance matching and maximizing power output. The controller adjusts the duty cycle by controlling the switching of the MOSFETs in the SEPIC circuit. Repeat the above process at regular intervals to ensure that the wireless charging device operates at maximum power output.

[0031] The efficiency information calculation formula in step C is as follows: (1) in, AC voltage source The current in the circuit containing the transmitting coil. The detuning factor, ; Coupling factor j is the imaginary part; , The power supply impedance is... The impedance of the transmitting coil (14) is... The impedance of the receiving end. The impedance of the load; The frequency generated by the high-frequency full-bridge inverter module; is the inherent resonant frequency of the resonant circuit; M is the mutual inductance between the transmitting coil and the receiving coil.

[0032] The vertical moving mechanism includes a vertical stepper motor, a vertical transmission mechanism, screw a, and screw b; The horizontal moving mechanism includes a horizontal stepper motor a4, a horizontal stepper motor b5, a horizontal rod a6, a horizontal rod b7, a horizontal sliding plate a8, a horizontal support plate a27, a horizontal support plate b28, a horizontal sliding plate b9, a screw c19, and a screw d20. The lower end of either screw a15 or screw b17 is connected to the output shaft of the vertical stepper motor 2, which is mounted on the top surface of the base 1. The lower end of the other screw is mounted on the top surface of the base 1 via a mounting bearing 40. Screws a15 and b17 are located on the left and right sides of the top surface of the base 1, respectively. The output shaft of the vertical stepper motor 2 is vertically upward, and both screws a15 and b17 are vertically positioned. Screws a15 and b17 are connected by a vertical transmission mechanism 3. The rear end of the horizontal stepper motor a4 is provided with a vertical drive thread through hole a16, which is used to install it on the screw a15. The rear end of the horizontal stepper motor b5 is provided with a vertical drive thread through hole b18, which is used to install it on the screw b17. The output shaft of the horizontal stepper motor a4 is horizontally positioned to the right, and a screw c19 with the same axial direction is mounted on it. A horizontal support plate b28 is mounted on the right side wall of the horizontal stepper motor a4, extending to the right and perpendicular to the screw c19. The output shaft of the horizontal stepper motor b5 is horizontally positioned to the rear, and a screw d20 with the same axial direction is mounted on it. A horizontal support plate a27 is mounted on the left side wall of the horizontal stepper motor b5, extending to the left and perpendicular to the screw d20. The screw d20 and the screw c19 are perpendicular. A horizontal sliding plate a8 is provided on the right side of the horizontal rod a6, and the horizontal sliding plate a8 is perpendicular to the horizontal rod a6; a horizontal sliding plate b9 is provided on the left side of the horizontal rod b7, and the horizontal sliding plate b9 is perpendicular to the horizontal rod b7; the horizontal sliding plate a8 is perpendicular to the horizontal sliding plate b9. The horizontal moving platform 10 is provided with sliding through holes a23 and b24 on its side, corresponding to the horizontal sliding plate a8 and the horizontal sliding plate b9, respectively. The sliding through holes a23 and b24 are spaced apart in the vertical direction. The horizontal sliding plate a8 and the horizontal sliding plate b9 are respectively inserted into the sliding through holes a23 and b24. The horizontal support plate a27 has a horizontal groove a along its longitudinal direction on its left side wall, and the end of the horizontal slide plate a8 extends into the horizontal groove a and can slide along the horizontal groove. The horizontal support plate b28 has a horizontal groove b along its longitudinal direction on its left side wall, and the end of the horizontal slide plate b9 extends into the horizontal groove b and can slide along the horizontal groove. The horizontal steering mechanism is a horizontal steering stepper motor 11, and the angle steering mechanism is an angle steering stepper motor 12. The horizontal steering stepper motor 11 is installed on the top surface of the horizontal moving platform 10. The output shaft of the horizontal steering stepper motor 11 is vertically upward, and the angle steering stepper motor 12 is installed on it. The output shaft of the angle steering stepper motor 12 is horizontal, and a swing rod 25 is installed on it. The upper end of the swing rod 25 is provided with a coil support 13, and the transmitting coil is located on the coil support 13.

[0033] The vertical transmission mechanism 3 includes sleeve a26, sleeve b30, transmission shaft 29, bevel gear a31, bevel gear b32, and bevel gear c33; bevel gear a31 and bevel gear b32 are respectively located at the lower part of screw a15 and screw b17. The sleeves a26 and b30 are mounted on the base 1; the sleeve a26 covers the vertical stepper motor 2 and the lower part of the screw a15; the top of the sleeve a26 is provided with a gear through hole 39 that allows the bevel gear a31 to pass through; the bottom surface of the sleeve a26 is an open structure; the side wall of the sleeve a26 is provided with a limiting shaft hole a34 and an inverted L-shaped through hole a35; the upper part of the limiting shaft hole a34 is connected to the upper front side of the L-shaped through hole a35; the lower end of the L-shaped through hole a35 is located at the lower end face of the sleeve a26, forming a rotating shaft channel; The sleeve b30 covers the bearing 40 and the lower part of the screw b17. The top of the sleeve b30 is provided with a through hole that allows the bevel gear b32 to pass through. The bottom surface of the sleeve b30 is an open structure. The side wall of the sleeve b30 is provided with a limiting shaft hole b36 and an inverted L-shaped through hole b37. The upper part of the limiting shaft hole b36 is connected to the upper rear side of the L-shaped through hole b37. The lower end of the L-shaped through hole b37 is located at the lower end face of the sleeve b30, forming a rotating shaft channel. The two sides of the drive shaft 29 are respectively placed in the limiting shaft hole a34 and the limiting shaft hole b36, and the two ends of the drive shaft 29 extend into the sleeve a26 and the sleeve b30 respectively. The two ends of the drive shaft 29 are respectively provided with bevel gears c, and the bevel gears c33 at the two ends of the drive shaft 29 mesh with bevel gears a31 and b32 respectively. The base 1 has mounting rings 38 with internal threads on its left and right sides respectively. The lower ends of the outer circular surfaces of the sleeves a26 and b30 are respectively provided with external threads corresponding to the internal threads. The sleeves a26 and b30 are installed on the mounting rings 38 on the left and right sides of the base 1 through threaded engagement.

[0034] In the description of this embodiment, the terms "up," "down," "left," "right," "front," and "back," etc., refer to directional or positional relationships based on the appendix. Figure 1The orientations or positional relationships shown are for ease of description and simplification of operation only, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0035] Example 2 Based on the method in Example 1, simulation was performed using MATLAB software. The simulation process involves the following formulas: Efficiency information and active power in a wireless power transmission system are as follows: (1) (2) Load power modulus is (3) right The maximum value of the modulus can be found by taking the derivative. (4) Then the normalized power of the load is (5) The efficiency of wireless power transmission is (6) (7) The resonant frequency of the circuit, calculated based on the given circuit parameters, is: (8) In the simulation, L=3μH, C=30nF, Rs=1Ω, R=3.5Ω, RL=20Ω, and M is taken as 10μH, 12μH, and 14μH respectively.

[0036] Obtained from Formula 7 Figure 3 A comparison chart of efficiency at the same frequency for different mutual inductance values. From Figure 3 It can be seen that at the resonant frequency of the system, the transmission efficiency of the system increases continuously with the increase of the mutual inductance value M, while the transmission efficiency of the system decreases significantly when the mutual inductance value is small.

[0037] Obtained from Formula 5 Figure 4 System Coupling State Diagrams and Figure 5 The system is undercoupled. As can be seen from the figure, the system's power curve is undercoupled at the coupling coefficient... Initially, no frequency splitting occurs when the coupling coefficient is increased, but frequency splitting occurs when the mutual inductance M value is too large.

[0038] Depend on Figure 3 and Figure 5It can be seen that the system's transmit power is very low in the undercoupled state. And by Figure 4 It can be seen that in the overcoupled region, the system no longer has only one resonant point; the original maximum point at the system's resonant frequency has become the minimum point.

[0039] Because undercoupling, critical coupling, and overcoupling of the system are all directly related to the mutual inductance M value, a mechanical module can be used to control the angular offset, radial offset, and distance between the transmitting and receiving coils. This adjusts the magnitude of the mutual inductance M value, and the phase-locked loop can be controlled using a particle swarm optimization (PI) algorithm to ensure the system maintains a resonant state. This improves system efficiency.

[0040] After the system resonates, in order to achieve critical coupling, the vertical positions of the transmitting and receiving coils are continuously adjusted after alignment following the above process. This process is achieved by changing the mutual inductance M using a mechanical structure, as shown in Table 1. After aligning the transmitting and receiving coils through the mechanical structure, the transmitting coil is made to resonate using an intelligent control algorithm. Then, the vertical direction between the coils is adjusted to indirectly adjust the value of the mutual inductance M. The transmission efficiency before and after adding the wireless power transmission device and particle swarm PI control of this invention is calculated using Formula 7. It can be seen that the system efficiency is greatly improved after this.

[0041] From Formula 2, we can obtain that Current With Thevenin circuit description Therefore, considering the load resistance, the active two-port network of the entire magnetically coupled resonant wireless power transfer system can be represented by the following Thevenin equivalent transformation: Figure 6 The model shown. The power output characteristic of the magnetically coupled resonant power transmission system can then be equivalent to a frequency of... The amplitude is Ud and the internal resistance is R. in The AC power supply. The system's maximum output power is at the load resistance R. load =R in When obtained, its value is In the perturbation-observation control algorithm, the change in duty cycle can be achieved by controlling the controllable DC-side impedance transformation, i.e., using a controllable SEPIC circuit to perform load impedance transformation. The load power of the transmitting coil is detected using a second power detection module. According to... Figure 6 We can use the controller to control the switching of MOSFETs in the SEPIC circuit via the perturbation observation method to adjust the circuit duty cycle in order to dynamically track the current system's maximum power point.

[0042] Table 1: Transmission efficiency of the system before and after the addition of the wireless power transmission device of the present invention and the adjustment and particle swarm PI control.

[0043]

Claims

1. A magnetically coupled resonant wireless power transfer method, characterized in that: A wireless charging device using the following structure: The wireless charging device includes a transmitting coil moving platform and a receiving coil; The transmitting coil moving platform includes a base (1), a vertical moving mechanism, a horizontal moving mechanism, a horizontal moving stage (10), a horizontal turning mechanism, an angle turning mechanism, a coil mounting platform, a coil support (13), a transmitting coil (14), a controller, a DC voltage source, a high-frequency full-bridge inverter module, a first communication module, and a first power detection module; The vertical moving mechanism is located on the base (1), and the horizontal moving mechanism is located on the vertical moving mechanism, and can be raised and lowered under the drive of the vertical moving mechanism; the horizontal moving platform (10) is located on the horizontal moving mechanism, and can move horizontally under the drive of the horizontal moving mechanism; the horizontal turning mechanism is located on the top surface of the horizontal moving platform (10); the angle turning mechanism is located on the horizontal turning mechanism, and can rotate under the drive of the horizontal turning mechanism; the coil support (13) is located on the angle turning mechanism, and the transmitting coil (14) is located on the coil support (13); The controller, DC voltage source, and high-frequency full-bridge inverter module are mounted on the base (1); the DC voltage source supplies power to each power-consuming module, and the DC voltage source supplies power to the transmitting coil (14) through the high-frequency full-bridge inverter module; the controller controls the operation of each module. The first communication module and the first power detection module are mounted on the coil bracket (13) and electrically connected to the controller; Its transmission method includes the following steps: A. Place the receiver above the transmitting coil. The controller controls the first communication module and the first power detection module to start working. The first power detection module detects the power of the transmitting coil (14) and transmits power, voltage, and current signals to the controller through the first communication module. The controller controls the horizontal moving mechanism to drive the transmitting coil to move 1cm in each of the four directions (front, back, left, and right) in the horizontal direction. After moving 1cm in each direction, it returns to its original position and then moves to the next direction. The controller compares the power of the transmitting coil (14) after moving in each direction and controls the horizontal moving mechanism to drive the transmitting coil to move 1cm to the position with the highest power. The position after the movement is taken as the original position for the next set of four directions (front, back, left, and right). This process is repeated until the power is not as high as the power at the previous position when moving to the next direction. Then, it returns to the previous position and the horizontal movement is terminated. B. The controller controls the angle steering mechanism to drive the transmitting coil to rotate in the vertical plane, adjusting the angle between the transmitting coil and the horizontal plane. The angle of the transmitting coil deviates by 1 degree. Then, the controller controls the horizontal steering mechanism to drive the transmitting coil to rotate 360 ​​degrees in the horizontal plane, and detects the power during this process. This process is repeated until the transmitting coil forms a 45-degree angle with the horizontal direction. The controller, based on the angle position corresponding to the maximum power, drives the transmitting coil to reach that position by controlling the angle steering mechanism and the horizontal steering mechanism. C. The controller controls the vertical moving mechanism to drive the transmitting coil to rise 1cm. Based on the power obtained from the first power detection module and the second power detection module, the controller calculates the efficiency at this position, restores the original position, and then descends 1cm. The controller calculates the efficiency at this position based on the power obtained from the first power detection module and the second power detection module, compares the efficiency of the upward and downward moving positions, and controls the vertical moving mechanism to drive the transmitting coil to move 1cm in the direction with greater efficiency. The moved position is used as the origin for the next set of upward and downward movements. This process is repeated until the transmitting coil reaches the position with the best efficiency.

2. The magnetically coupled resonant wireless power transfer method as described in claim 1, characterized in that: It also includes the following steps: D. Obtain the current and voltage waveforms of the current transmitting coil (14) through the current phase sampling module and the voltage phase sampling module, and input them into the controller; The controller compares the phases of the voltage and current signals to obtain the error signal, and uses the particle swarm PID algorithm to control the error signal so that the voltage and current phase difference is 0. The controller internally implements a voltage-controlled oscillator and generates a PWM wave to drive the high-frequency full-bridge inverter module to achieve system resonance. The voltage phase acquisition module and the current phase acquisition module are both mounted on the coil support (13).

3. The magnetically coupled resonant wireless power transfer method as described in claim 2, characterized in that: The receiving end is equipped with a second communication module and a second power detection module; the second power detection module detects the power of the receiving coil load and transmits data to the controller through the second communication module; Throughout step AD, the controller sets the sampling time interval and uses the second power detection module to detect the load power and load voltage across the load terminals of the receiving coil. The controller then uses the read load power and load voltage to calculate and control the SEPIC circuit using the perturbation-observation algorithm. The control process is as follows: Compare the power of the receiving coil load at the previous moment and the current moment; if the load power at the current moment is greater than the load power at the previous moment, compare the load voltage at the current moment and the load voltage at the previous moment. If the load voltage at the current moment is greater than the load voltage at the previous moment, the controller increases the duty cycle by 1%. If the voltage value at the current moment is less than or equal to the voltage value at the previous moment, the controller decreases the duty cycle by 1%. If the load power at the current moment is less than the load power at the previous moment, compare the load voltage at the current moment with the load voltage at the previous moment. If the load voltage at the current moment is greater than the load voltage at the previous moment, the controller increases the duty cycle by 1%. If the load voltage at the current moment is less than or equal to the load voltage at the previous moment, the controller decreases the duty cycle by 1%. The above process continues until the load power at the current moment equals the load power at the previous moment. At this point, the duty cycle reaches its optimal value, achieving impedance matching and maximizing power output. The controller adjusts the duty cycle by controlling the switching on and off of the MOSFETs in the SEPIC circuit. Repeat the above process at regular intervals to ensure that the wireless charging device operates at maximum power output.

4. The magnetically coupled resonant wireless power transfer method as described in claim 2, characterized in that: The efficiency information calculation formula in step C is as follows: （1） in, AC voltage source The current in the circuit containing the transmitting coil. The detuning factor, ; Coupling factor j is the imaginary part; , The power supply impedance is... The impedance of the transmitting coil (14) is... The impedance of the receiving end, The impedance of the load; The frequency generated by the high-frequency full-bridge inverter module; is the inherent resonant frequency of the resonant circuit; M is the mutual inductance between the transmitting coil and the receiving coil.

5. The magnetically coupled resonant wireless power transfer method as described in claim 1, characterized in that: The vertical moving mechanism includes a vertical stepper motor (2), a vertical transmission mechanism (3), screw a (15), and screw b (17); The horizontal moving mechanism includes a horizontal stepper motor a (4), a horizontal stepper motor b (5), a horizontal rod a (6), a horizontal rod b (7), a horizontal sliding plate a (8), a horizontal support plate a (27), a horizontal support plate b (28), a horizontal sliding plate b (9), a screw c (19), and a screw d (20). The lower end of one of the screws a (15) or b (17) is connected to the output shaft of the vertical stepper motor (2). The vertical stepper motor (2) is mounted on the top surface of the base (1). The lower end of the other screw is mounted on the top surface of the base (1) via a mounting bearing (40). Screws a (15) and b (17) are located on the left and right sides of the top surface of the base (1), respectively. The output shaft of the vertical stepper motor (2) is set vertically upward. Both screws a (15) and b (17) are set vertically. Screws a (15) and b (17) are connected by a vertical transmission mechanism (3). The horizontal stepper motor a (4) is provided with a vertical drive thread through hole a (16) at its rear end, and is installed on the screw a (15) through the vertical drive thread through hole a (16). The horizontal stepper motor b (5) is provided with a vertical drive thread through hole b (18) at its rear end, and is installed on the screw b (17) through the vertical drive thread through hole b (18). The output shaft of the horizontal stepper motor a (4) is set horizontally to the right, and a screw c (19) with the same axial direction is provided on it. A horizontal support plate b (28) is installed on the right side wall of the horizontal stepper motor a (4). The horizontal support plate b (28) extends to the right and is perpendicular to the screw c (19). The output shaft of the horizontal stepper motor b (5) is set horizontally to the rear, and a screw d (20) with the same axial direction is provided on it. A horizontal support plate a (27) is installed on the left side wall of the horizontal stepper motor b (5). The horizontal support plate a (27) extends to the left and is perpendicular to the screw d (20). The screw d (20) and the screw c (19) are perpendicular. A horizontal sliding plate a (8) is provided on the right side of the horizontal rod a (6), and the horizontal sliding plate a (8) is perpendicular to the horizontal rod a (6); a horizontal sliding plate b (9) is provided on the left side of the horizontal rod b (7), and the horizontal sliding plate b (9) is perpendicular to the horizontal rod b (7); the horizontal sliding plate a (8) is perpendicular to the horizontal sliding plate b (9). The horizontal moving platform (10) is provided with sliding through holes a (23) and sliding through holes b (24) corresponding to the horizontal sliding plate a (8) and horizontal sliding plate b (9) respectively on its side. The sliding through holes a (23) and sliding through holes b (24) are arranged at intervals in the vertical direction. The horizontal sliding plate a (8) and horizontal sliding plate b (9) are respectively inserted into the sliding through holes a (23) and sliding through holes b (24). The horizontal support plate a (27) has a horizontal groove a along its longitudinal direction on its left side wall, and the end of the horizontal slide plate a (8) extends into the horizontal groove a and can slide along the horizontal groove. The horizontal support plate b (28) has a horizontal groove b along its longitudinal direction on the left side wall, and the end of the horizontal slide plate b (9) extends into the horizontal groove b and can slide along the horizontal groove. The horizontal steering mechanism is a horizontal steering stepper motor (11), and the angle steering mechanism is an angle steering stepper motor (12). The horizontal steering stepper motor (11) is provided on the top surface of the horizontal moving platform (10). The output shaft of the horizontal steering stepper motor (11) is set vertically upward, and the angle steering stepper motor (12) is installed on it. The output shaft of the angle steering stepper motor (12) is set horizontally, and the swing rod (25) is installed on it. The upper end of the swing rod (25) is provided with a coil bracket (13), and the transmitting coil is set on the coil bracket (13).

6. The magnetically coupled resonant wireless power transfer method as described in claim 5, characterized in that: The vertical transmission mechanism (3) includes sleeve a (26), sleeve b (30), transmission shaft (29), bevel gear a (31), bevel gear b (32), and bevel gear c (33); the bevel gear a (31) and bevel gear b (32) are respectively located at the lower part of screw a (15) and screw b (17); The sleeve a (26) and sleeve b (30) are installed on the base (1); the sleeve a (26) covers the lower part of the vertical stepper motor (2) and the screw a (15); the top of the sleeve a (26) is provided with a gear through hole (39) that allows the bevel gear a (31) to pass through; the bottom surface of the sleeve a (26) is an open structure; the side wall of the sleeve a (26) is provided with a limiting shaft hole a (34) and an inverted L-shaped through hole a (35); the upper part of the limiting shaft hole a (34) is connected to the upper front side of the L-shaped through hole a (35); the lower end of the L-shaped through hole a (35) is located at the lower end face of the sleeve a (26), forming a rotating shaft channel; The sleeve b (30) covers the lower part of the mounting bearing (40) and the screw b (17). The top of the sleeve b (30) is provided with a through hole that allows the bevel gear b (32) to pass through. The bottom surface of the sleeve b (30) is an open structure. The side wall of the sleeve b (30) is provided with a limiting shaft hole b (36) and an inverted L-shaped through hole b (37). The upper part of the limiting shaft hole b (36) is connected to the upper rear side of the L-shaped through hole b (37). The lower end of the L-shaped through hole b (37) is located at the lower end face of the sleeve b (30), forming a rotating shaft channel. The two sides of the drive shaft (29) are respectively placed in the limiting shaft hole a (34) and the limiting shaft hole b (36), and the two ends of the drive shaft (29) extend into the sleeve a (26) and the sleeve b (30) respectively. The two ends of the drive shaft (29) are respectively provided with bevel gear c, and the bevel gear c (33) at both ends of the drive shaft (29) meshes with bevel gear a (31) and bevel gear b (32) respectively. The base (1) is provided with mounting rings (38) with internal threads on the left and right sides respectively. The lower ends of the outer circular surfaces of the sleeves a (26) and b (30) are respectively provided with external threads corresponding to the internal threads. The sleeves a (26) and b (30) are installed on the mounting rings (38) on the left and right sides of the base (1) through threaded engagement.

7. The magnetically coupled resonant wireless power transfer method as described in claim 2, characterized in that: The voltage phase acquisition module is a voltage sampling circuit composed of a chip and resistors and capacitors, and the current phase acquisition module is a current sampling circuit composed of a chip and resistors and capacitors.

8. The magnetically coupled resonant wireless power transfer method as described in claim 7, characterized in that: The voltage phase acquisition module uses an NE5532P chip; the current phase acquisition module uses a CC6920 chip.

9. The magnetically coupled resonant wireless power transfer method as described in claim 1, characterized in that: The controller uses an STM-32 microprocessor.

10. A wireless power transfer device, implementing the magnetically coupled resonant wireless power transfer method as described in any one of claims 1-9, characterized in that: It also includes a housing, in which the transmitting coil moving platform is located, and the top surface of the housing is used to place the wireless charging receiver.

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