Wireless power transmission system for adjusting matching network and operation method thereof

Abstract

A wireless power transmission system and its operating method for adjusting a matching network are disclosed. The wireless power transmission system includes a transmitting coil, a matching network, an adjustment unit, a sensor, a driving unit, and a microcontroller. By automatically adjusting the output capacitor impedance to achieve resonant frequency matching with the matching network, stable and efficient charging can be maintained under different dynamic distances.

Description

Technical Field

[0001] This invention relates to a wireless power transmission system and its operating method, and more particularly to a wireless power transmission system and its operating method for adjusting a matching network. Prior Technology

[0002] Wireless charging, also known as contactless inductive charging, uses coil induction to transfer energy from a power transmission unit to a power receiving device. The power receiving device is installed in the device to be charged, and after receiving the energy, it charges the battery inside the electronic device.

[0003] Impedance matching is one of the factors determining the efficiency of wireless charging. In the power transmission unit, a matching network is provided between the power amplifier and the transmitting coil. This matching network is used to impedance match the power amplifier and the transmitting coil, thereby improving charging efficiency. Furthermore, the power transmission unit further includes a bidirectional metal-oxide-semiconductor field-effect transistor or transformer coupled to the matching network. This bidirectional metal-oxide-semiconductor field-effect transistor or transformer allows for fine-tuning of the impedance matching, further improving charging efficiency.

[0004] However, in wireless charging technology, because the receiving power amplifier can vary in the x, y, and z axes of space, it can cause matching failure and instability, which in turn leads to decreased efficiency and component damage.

[0005] Therefore, in order to overcome the shortcomings and deficiencies of the existing technology, it is necessary to provide an improved wireless power transmission system for adjusting matching networks to solve the problems existing in the above-mentioned conventional technology. Summary of the Invention

[0006] The main objective of this invention is to provide a wireless power transmission system and its operation method, which automatically adjusts the output capacitor impedance to achieve resonance frequency matching with the matching network, thereby ensuring stable and efficient charging efficiency under different dynamic distances.

[0007] To achieve the above objectives, the present invention provides a wireless power transmission system for adjusting a matching network, comprising a transmitting coil, a matching network, an adjustment unit, a sensor, a driving unit, and a microcontroller; the transmitting coil is used to transmit energy to a receiving coil of a power receiving device; the matching network is coupled to the transmitting coil; the adjustment unit is coupled to the matching network and configured to adjust the impedance of an output capacitor to match the impedance of the matching network and the transmitting coil; the sensor is coupled to the matching network and configured to detect a phase of the matching network and a lead message of the matching network, wherein the lead message includes a voltage phase leading a current phase or a current phase leading a voltage phase; the driving unit is coupled to the adjustment unit and configured to drive the adjustment unit to switch; the microcontroller is coupled to the driving unit and the sensor and configured to send a driving signal to the driving unit to control the adjustment unit to adjust the output capacitor impedance based on the phase and lead message transmitted by the sensor.

[0008] In one embodiment of the present invention, the adjustment unit includes a plurality of switching switches and a plurality of capacitors, the switching switches being coupled to the capacitors respectively, the capacitors being coupled to a matching network, and the driving unit being configured to control an on / off state of the switching switches to adjust the output capacitor impedance.

[0009] In one embodiment of the present invention, the wireless power transmission system further includes a DC power supply unit coupled to the drive unit, the DC power supply unit being configured to provide a DC voltage to the drive unit.

[0010] In one embodiment of the present invention, the power receiving device further includes a power distribution unit and a rechargeable battery. The power distribution unit is coupled to the receiving coil, and the rechargeable battery is coupled to the power distribution unit. The power distribution unit is configured to store the power received by the receiving coil into the rechargeable battery.

[0011] In one embodiment of the present invention, the microcontroller is configured to calculate a time-varying efficiency based on a first voltage value and a first current value of a DC power supply unit and a second voltage value and a second current value of a rechargeable battery, and to determine the output capacitor impedance based on the time-varying efficiency.

[0012] In one embodiment of the present invention, the driving unit includes a pre-driver and a power amplifier. The pre-driver is coupled to the power amplifier and is configured to provide a pre-drive voltage to the power amplifier. The power amplifier receives the pre-drive voltage and amplifies the pre-drive voltage to generate a voltage output to the adjustment unit.

[0013] In one embodiment of the present invention, the wireless power transmission system further includes a first Bluetooth unit, which is coupled to a microcontroller and configured to communicate with a second Bluetooth unit of a power receiving device.

[0014] In one embodiment of the present invention, the adjustment unit is initially set such that half of the switching switches are in an on / off state and the other half are in an off state.

[0015] To achieve the above objectives, the present invention provides an operating method for adjusting a wireless power transmission system of a matching network. The operating method includes: detecting a phase of a matching network and a lead information of the matching network through a sensor, wherein the lead information includes a voltage phase leading a current phase or a current phase leading a voltage phase; and using a microcontroller to send a drive signal to a drive unit to control an adjustment unit based on the phase transmitted by the sensor and the lead information, so as to adjust the output capacitor impedance.

[0016] In one embodiment of the present invention, after adjusting the output capacitor impedance, the operation method further includes: using a microcontroller to calculate a time-varying efficiency based on a first voltage and a first current of a DC power supply unit and a second voltage and a second current of a rechargeable battery of a power receiving device, and determining the output capacitor impedance based on the time-varying efficiency.

[0017] As described above, the wireless power transmission system can automatically adjust the output capacitor impedance through an adjustment unit, thereby achieving resonance frequency matching with the matching network. The system then compares the output capacitor impedance before and after adjustment with its corresponding time-varying efficiency to find the optimal matching combination. In other words, this invention can automatically adjust the matching parameters according to the distance between the charging device and the receiving device and environmental changes, ensuring stable and efficient charging under different dynamic distances. This not only improves charging stability but also reduces energy loss caused by distance changes, further enhancing overall system performance and effectively solving problems such as energy loss, efficiency degradation, and power amplifier damage caused by matching network failure. Simple Explanation of the Diagram

[0018] Figure 1 is a schematic diagram of an embodiment of the wireless power transmission system of the present invention for adjusting a matching network.

[0019] Figure 2 is a schematic diagram of an adjustment unit of an embodiment of the wireless power transmission system for adjusting a matching network according to the present invention.

[0020] Figure 3 is a flowchart of an embodiment of the operation method of the wireless power transmission system for adjusting the matching network according to the present invention. Implementation

[0021] To make the above and other objects, features, and advantages of the present invention more apparent and understandable, embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings. Furthermore, the directional terms used in this invention, such as up, down, top, bottom, front, back, left, right, inside, outside, side, surrounding, center, horizontal, transverse, vertical, longitudinal, axial, radial, uppermost, or lowermost, are merely for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrating and understanding the present invention, and not for limiting the present invention. It should be noted that the drawings are simplified schematic diagrams; therefore, only elements and combinations related to the present invention are shown to provide a clearer description of the basic structure or implementation method of the present invention, while the actual elements and layout may be more complex. In addition, for ease of explanation, the elements shown in the various drawings of the present invention are not drawn to scale according to the actual number, shape, and size; the detailed scale can be adjusted according to design requirements.

[0022] Referring to Figure 1, which is a schematic diagram of an embodiment of the wireless power transmission system for adjusting the matching network of the present invention, the wireless power transmission system A for adjusting the matching network includes a transmitting coil 51, a matching network 4, an adjusting unit 3, a sensor 6, a driving unit 2 and a microcontroller 1. The detailed structure, assembly relationship and operating principle of each component will be described in detail below.

[0023] The transmitting coil 51 is used to transfer energy to a receiving coil 52 of a power receiving device B, and the matching network 4 is coupled to the transmitting coil 51. Specifically, the transmitting coil 51 is used to transfer energy to the receiving coil 52 of the power receiving device B in a magnetic resonance manner for wireless charging.

[0024] Adjustment unit 3 is coupled to matching network 4. Adjustment unit 3 is configured to adjust the impedance of an output capacitor to match the impedance of matching network 4 with that of transmitting coil 51. Sensor 6 is coupled to matching network 4. Sensor 6 is configured to detect a phase of matching network 4 and a lead message of matching network 4, wherein the lead message includes voltage phase leading current phase or current phase leading voltage phase. For example... This indicates that the voltage phase leads the current phase (inductive load). This indicates that the current phase leads the voltage phase (capacitive load).

[0025] The drive unit 2 is coupled to the adjustment unit 3, and the drive unit 2 is configured to drive the adjustment unit 3 to switch. Specifically, the drive unit 2 includes a pre-driver 21 and a power amplifier 22. The pre-driver 21 is coupled to the power amplifier 22 and is used to provide a pre-drive voltage to the power amplifier 22. The power amplifier 22 receives the pre-drive voltage and amplifies the pre-drive voltage to generate a voltage output to the adjustment unit 3.

[0026] Microcontroller 1 is coupled to drive unit 2 and sensor 6. Microcontroller 1 is configured to send a drive signal to drive unit 2 to control adjustment unit 3 to adjust output capacitor impedance based on phase and lead information transmitted by sensor 6.

[0027] Figure 2 shows a schematic diagram of an adjustment unit in an embodiment of a wireless power transmission system for adjusting a matching network according to the present invention. Specifically, the adjustment unit 3 includes multiple switches 31 and multiple capacitors 32. The switches 31 are coupled to the capacitors 32, and the capacitors 32 are coupled to the matching network 4. The driving unit 2 controls the on / off state of the switches 31 through the voltage output by the power amplifier 22 to adjust the output capacitor impedance, for example, by turning on a specific number of capacitors 32. In this embodiment, the adjustment unit 3 is initially set so that half of the switches 31 are on and the other half are off, so that half of the capacitors 32 are turned on. The output capacitor impedance is then determined based on the initial setting of the half of the capacitors 32 being turned on to determine whether further adjustment is needed. For example, when the voltage phase leads the current phase, the output capacitor impedance is increased (increasing the number of capacitors turned on); when the current phase leads the voltage phase, the capacitor value is decreased (reducing the number of capacitors turned on).

[0028] The wireless power transmission system A further includes a DC power supply unit 7, which is coupled to the drive unit 2 and configured to provide a DC voltage to the drive unit. Specifically, the DC power supply unit 7 is used to output a DC voltage to the power amplifier 22.

[0029] The power receiving device B further includes a power distribution unit 81 and a rechargeable battery 82. The power distribution unit 81 is coupled to the receiving coil 52, and the rechargeable battery 82 is coupled to the power distribution unit 81. The power distribution unit 81 is configured to store the power received by the receiving coil 52 into the rechargeable battery 82.

[0030] Microcontroller 1 is configured to operate based on a first voltage value from DC power supply unit 7. With a first current value And a second voltage value of rechargeable battery 82 With a second current value Calculate time-varying efficiency The output capacitor impedance is determined based on the time-varying efficiency. For example, if the time-varying efficiency of N conducting capacitors is better than that of N+1 conducting capacitors, the number of conducting capacitors is adjusted to N. In this embodiment, the equation for time-varying efficiency is:

[0031] The wireless power transmission system A further includes a first Bluetooth unit 91, which is coupled to the microcontroller 1 and used to communicate with a second Bluetooth unit 92 of the power receiving device B. In this embodiment, the second Bluetooth unit 92 can transmit information about voltage, current overload, and overtemperature to the first Bluetooth unit 91 for subsequent adjustments by the microcontroller 1.

[0032] Based on the above structure, the wireless power transmission system can automatically adjust the output capacitor impedance through the adjustment unit 3, thereby achieving resonance frequency matching with the matching network 4. The system then compares the output capacitor impedance before and after adjustment with its corresponding time-varying efficiency to find the optimal matching combination. In other words, this invention can automatically adjust the matching parameters according to the distance between the charging device and the receiving device and environmental changes, ensuring stable and efficient charging under different dynamic distances. This not only improves charging stability but also reduces energy loss caused by distance changes, further enhancing overall system performance and effectively solving problems such as energy loss, efficiency reduction, and power amplifier damage caused by matching network failure.

[0033] Referring to Figure 3, a flowchart of an embodiment of the operation method of the wireless power transmission system for adjusting a matching network according to the present invention is shown. The operation method is performed using the aforementioned wireless power transmission system and includes steps S201, S202, and S203. The operation steps and operating principles of each component will be described in detail below.

[0034] In step S201, a phase of a matching network 4 and a lead message of the matching network 4 are detected by a sensor 6, wherein the lead message includes a voltage phase leading a current phase or a current phase leading a voltage phase.

[0035] In step S202, a microcontroller 1 sends a drive signal to the drive unit 2 to control the adjustment unit 3 based on the phase and lead information transmitted by the sensor 6, so as to adjust the output capacitor impedance.

[0036] In step S203, the microcontroller 1 utilizes a first voltage based on the DC power supply unit 7. With a first current and the second voltage value of a rechargeable battery 82 of a power receiving device B. With the second current value Calculate time-varying efficiency Furthermore, the output capacitor impedance is determined based on the time-varying efficiency. The equation for the time-varying efficiency is:

[0037] In this embodiment, the adjustment unit 3 includes multiple switches 31 and multiple capacitors 32. The adjustment unit 3 is initially set so that half of the switches 31 are in an "on" state and the other half are in a "off" state, causing half of the capacitors 32 to conduct. The output capacitor impedance is then used to determine whether further adjustment is needed. For example, when the voltage phase leads the current phase, the output capacitor impedance is increased (increasing the number of conducting capacitors); when the current phase leads the voltage phase, the capacitor value is decreased (reducing the number of conducting capacitors).

[0038] As described above, by using the adjustment unit 3 to automatically adjust the output capacitor impedance, and thus achieve resonance frequency matching with the matching network 4, it is possible to ensure stable and efficient charging efficiency under different dynamic distances. This not only improves charging stability but also reduces energy loss caused by distance changes, further enhancing the overall system performance and effectively solving problems such as energy loss, efficiency reduction, and power amplifier damage caused by matching network failure.

[0039] It should be noted that although specific embodiments have been described in this invention, these embodiments should also be understood as descriptions of the corresponding methods. Therefore, system or structural elements should be considered as specific manifestations of the corresponding method steps or their features. Similarly, the types mentioned in the context of method steps can also be interpreted as descriptions of specific components or details of the corresponding device. Some or all of the method steps can be performed by hardware devices such as microcontrollers, programmable computers, or electronic circuits. In some embodiments, several main method steps may be performed by such devices.

[0040] Although the present invention has been disclosed by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0041] A: Wireless power transmission system 1: Microcontroller 2: Drive Unit 21: Pre-driver 22: Power Amplifier 3: Adjustment Unit 31: Switch 32: Capacitor 4: Matching network 51: Transmitting coil 6: Sensors 7: DC power supply unit B: Power receiving device 52: Receiving coil 81: Power Distribution Unit 82: Rechargeable battery 91: First Bluetooth Unit 92: Second Blue Buddy Unit S201-S203: Steps

Claims

1. A wireless power transmission system for adjusting a matching network, comprising: a transmitting coil for transmitting energy to a receiving coil of a power receiving device; a matching network coupled to the transmitting coil; an adjustment unit coupled to the matching network, the adjustment unit configured to adjust the impedance of an output capacitor to impedance match the matching network with the transmitting coil; a sensor coupled to the matching network, the sensor configured to detect a phase of the matching network and a lead message of the matching network, wherein the lead message includes a voltage phase leading a current phase or a current phase leading a voltage phase; a drive unit coupled to the adjustment unit, the drive unit configured to drive the adjustment unit to switch; and a microcontroller coupled to the drive unit and the sensor, the microcontroller configured to send a drive signal to the drive unit to control the adjustment unit to adjust the output capacitor impedance based on the phase and the lead message transmitted by the sensor.

2. The wireless power transmission system for adjusting a matching network as described in claim 1, wherein the adjusting unit includes a plurality of switching switches and a plurality of capacitors, the switching switches being coupled to the capacitors, the capacitors being coupled to the matching network, and the driving unit being configured to control an on / off state of the switching switches to adjust the impedance of the output capacitors.

3. The wireless power transmission system for adjusting a matching network as described in claim 2, wherein the wireless power transmission system further includes a DC power supply unit coupled to the drive unit, the DC power supply unit being configured to provide a DC voltage to the drive unit.

4. The wireless power transmission system for adjusting a matching network as described in claim 3, wherein the power receiving device further includes a power distribution unit and a rechargeable battery, the power distribution unit being coupled to the receiving coil, the rechargeable battery being coupled to the power distribution unit, and the power distribution unit being configured to store the power received by the receiving coil into the rechargeable battery.

5. The wireless power transmission system for adjusting a matching network as described in claim 4, wherein, The microcontroller is configured to calculate a time-varying efficiency based on a first voltage and a first current value of the DC power supply unit and a second voltage and a second current value of the rechargeable battery, and to determine the output capacitor impedance based on the time-varying efficiency.

6. The wireless power transmission system for adjusting a matching network as described in claim 1, wherein the drive unit includes a pre-driver and a power amplifier, the pre-driver being coupled to the power amplifier, the pre-driver being configured to provide a pre-drive voltage to the power amplifier, the power amplifier receiving the pre-drive voltage and amplifying the pre-drive voltage to generate a voltage output to the adjustment unit.

7. The wireless power transmission system for adjusting a matching network as described in claim 1, wherein the wireless power transmission system further includes a first Bluetooth unit coupled to the microcontroller and configured to communicate with a second Bluetooth unit of the power receiving device.

8. The wireless power transmission system for adjusting a matching network as described in claim 2, wherein the adjustment unit is initially set such that half of the switching switches are in an on / off state and the other half are in an off / off state.

9. A method of operating a wireless power transmission system for adjusting a matching network, the method comprising: detecting a phase of a matching network and a lead message of the matching network via a sensor, wherein the lead message includes a voltage phase leading a current phase or a current phase leading a voltage phase; and using a microcontroller to send a drive signal to a drive unit to control an adjustment unit to adjust the impedance of an output capacitor based on the phase transmitted by the sensor and the lead message.

10. The method of operating a wireless power transmission system for adjusting a matching network as described in claim 9, wherein after adjusting the output capacitor impedance, the method further comprises: using the microcontroller to calculate a time-varying efficiency based on a first voltage and a first current of a DC power supply unit and a second voltage and a second current of a rechargeable battery of a power receiving device, and determining the output capacitor impedance based on the time-varying efficiency.

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