An integrated coil and magnetic near field coupling wireless power transfer system

Abstract

The application provides an integrated coil, comprising: an energy transmission coil for energy transmission and an information transmission coil arranged in the energy transmission coil for information transmission, wherein the information transmission coil is composed of two DDP coils arranged vertically and stacked, the two DDP coils are decoupled by being arranged perpendicularly to each other, two D coils in each DDP coil are excited reversely to generate a polarization magnetic field to be decoupled with the energy transmission coil outside. The application also provides a magnetic near-field coupling type wireless signal and energy transmission system, comprising: a transmitting end integrated coil, comprising a transmitting end energy transmission coil and a transmitting end information transmission coil arranged in the transmitting end energy transmission coil; a receiving end integrated coil, arranged opposite to the transmitting end integrated coil, comprising a receiving end energy transmission coil and a receiving end information transmission coil arranged in the receiving end energy transmission coil, wherein the transmitting end integrated coil and the receiving end integrated coil are equal in size and symmetrical in structure.

Description

Technical Field

[0001] This invention belongs to the field of wireless power transmission technology, specifically relating to an integrated coil and a magnetic near-field coupling wireless power transmission system. Background Technology

[0002] Wireless charging technology, with its advantages of no contact sparks, small footprint, and strong environmental adaptability, has broad application prospects in fields such as electric vehicles, aerospace, and biomedicine. To control the wireless charging process, stable and efficient information exchange is required between the transmitter and receiver.

[0003] Current wireless signal transmission systems have the following shortcomings:

[0004] 1. Traditional communication methods (Bluetooth, WIFI, ZigBee) require a long "handshake" time and additional modules, increasing the complexity of the system.

[0005] 2. Parallel transmission of energy and information is achieved by combining inductive and capacitive elements. The inductive element transmits energy, while the aluminum plate transmits information and provides magnetic shielding protection to reduce magnetic flux leakage. However, when the primary and secondary sides are offset, the efficiency of the capacitive element drops sharply; and due to the eddy current effect of the aluminum plate under the high-frequency magnetic field, the power of energy transmission is not high.

[0006] 3. Based on energy transmission, an encoding switch is added, and the principle of frequency division multiplexing is used to transmit energy and signals. However, this method cannot achieve simultaneous transmission of energy and signals.

[0007] 4. Parallel transmission of energy and information using triangular wave current. The fundamental frequency is used for energy transmission, and the third harmonic is used for information transmission. Because the fundamental frequency and the triangular wave have different frequencies, the coupling frequency of the wireless power transmission system will be affected, leading to a decrease in energy transmission efficiency.

[0008] 5. A dual-resonant structure is designed for parallel transmission of energy and signal, with the low-frequency resonant point used for energy transmission and the high-frequency resonant point used for information transmission. The accuracy of the capacitors and inductors in the compensation circuit has a significant impact on the system performance, making it impractical. Summary of the Invention

[0009] This invention is made to solve the above-mentioned problems, and aims to provide an integrated coil and a magnetic near-field coupling wireless signal and power transmission system.

[0010] The present invention provides an integrated coil, characterized by comprising: an energy transmission coil for energy transmission and an information transmission coil disposed within the energy transmission coil for information transmission, wherein the information transmission coil is composed of two vertically stacked DDP coils, the two DDP coils being mutually decoupled by being arranged perpendicularly to each other, and the two D coils within each DDP coil being subjected to reverse excitation to generate a polarized magnetic field, thereby decoupling from the outer energy transmission coil.

[0011] The integrated coil provided by this invention may also have the following feature: the energy transmission coil is disc-shaped.

[0012] The present invention also provides a magnetic near-field coupling wireless signal and power transmission system, characterized by comprising: a transmitter integrated coil, including a transmitter power transmission coil and a transmitter information transmission coil disposed within the transmitter power transmission coil.

[0013] The receiver integrated coil, positioned opposite the transmitter integrated coil, includes a receiver energy transmission coil and a receiver information transmission coil disposed within the receiver energy transmission coil.

[0014] The transmitting end integrated coil and the receiving end integrated coil are of equal size and have symmetrical structures.

[0015] This invention also provides a near-field coupled wireless signal-to-energy transmission method, characterized by employing a magnetic near-field coupled wireless signal-to-energy transmission system for signal-to-energy transmission, including: simultaneous energy transmission and information transmission between the transmitting end integrated coil and the receiving end integrated coil.

[0016] During energy transfer, a magnetically coupled wireless power transfer system with dual-sided series compensation is used between the transmitting and receiving energy transfer coils to complete the energy transfer process.

[0017] During information transmission, the modulated signal is first loaded onto the transmitting end information transmission coil via amplitude shift keying (APS), then the signal is transmitted to the receiving end information transmission coil via a high-frequency magnetic field, and finally the induced voltage of the receiving end information transmission coil is filtered and demodulated to complete the signal transmission.

[0018] The role and effect of invention

[0019] According to the integrated coil of the present invention, by utilizing a hollow region with low magnetic induction intensity inside a disk-shaped energy transmission coil and placing an information transmission coil inside the energy transmission coil, the cross-interference between the energy channel and the information channel can be reduced, achieving efficient integration. Furthermore, according to the integrated coil structure designed according to the present invention, the information transmission coil is composed of two vertically stacked DDP coils, which can realize enhanced magnetic near-field coupling wireless communication. The two D coils in each DDP coil are excited in opposite directions to generate a polarized magnetic field, thereby decoupling from the outer disk energy transmission coil. At the same time, the two DDP coils are arranged vertically, which can achieve mutual decoupling. Furthermore, the magnetic near-field coupled wireless signal and power transmission system of the present invention consists of two integrated coils serving as the transmitting and receiving ends, respectively. This not only enables cross-decoupling of the information transmission coils and energy transmission coils on both the transmitting and receiving sides during parallel energy and signal transmission, but also achieves mutual decoupling of the information transmission coils on one side themselves. It also enables miniaturization and integration of the wireless signal and power transmission system structure. Moreover, each module of the magnetic near-field coupled wireless signal and power transmission system of the present invention operates independently, solving the problem of reduced wireless power transmission power caused by frequency division multiplexing, and has immediacy, without the excessively long matching time of traditional information transmission. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the integrated coil structure in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the magnetic induction intensity of the energy transmission coil in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the magnetic near-field coupling wireless signal and power transmission system in an embodiment of the present invention;

[0023] Figure 4 This is a side view of the magnetic near-field coupling wireless signal and power transmission system in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the magnetic field distribution of the DDP coil under different excitations in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the magnetic field distribution of four sets of mutually perpendicular reverse-excitation DDP coils in an embodiment of the present invention;

[0026] Figure 7 This is an equivalent circuit diagram of energy transmission in an embodiment of the present invention;

[0027] Figure 8 This is the signal modulation method in the embodiments of the present invention;

[0028] Figure 9This is an equivalent circuit diagram of information modulation and demodulation in an embodiment of the present invention;

[0029] Figure 10 This is a waveform diagram of the signal modulated and demodulated according to the information in the embodiment of the present invention;

[0030] Figure 11 The images show physical diagrams of two types of integrated coils in embodiments of the present invention.

[0031] Figure 12 This is a wireless power simulation diagram of a disk-shaped power transmission coil in an embodiment of the present invention;

[0032] Figure 13 The diagram shows the wireless power simulation of two integrated coils in the embodiments of the present invention. Detailed Implementation

[0033] To make the technical means and effects of the present invention easy to understand, the present invention will be specifically described below in conjunction with embodiments and accompanying drawings.

[0034] <Example>

[0035] Figure 1 This is a schematic diagram of the integrated coil structure in an embodiment of the present invention.

[0036] like Figure 1 As shown, an integrated coil 100 of this embodiment includes an energy transmission coil 1 for energy transmission and an information transmission coil 2 for information transmission disposed within the energy transmission coil 1.

[0037] The information transmission coil 2 consists of two vertically stacked DDP coils. The two DDP coils are decoupled from each other by being arranged perpendicularly to each other. The two D coils in each DDP coil are excited in opposite directions to generate a polarized magnetic field, which is decoupled from the energy transmission coil 1 on the outside.

[0038] The energy transmission coil 1 is disc-shaped.

[0039] Figure 2 This is a schematic diagram of the magnetic induction intensity of the energy transmission coil in an embodiment of the present invention.

[0040] like Figure 2 As shown, for the magnetic induction intensity at different positions of the disk-shaped energy transmission coil 1, the magnetic induction intensity is greatest at the part directly facing the coil, decreasing outwards along the perimeter of the coil, and is essentially zero at a distance of 100mm from the coil; the magnetic induction intensity in the inner diameter of the coil decreases with increasing distance from the coil, and the change in magnetic induction intensity in the inner diameter is relatively gradual. From the formula for induced electromotive force, we can see that:

[0041]

[0042] When the information transmission coil 2 moves within the inner diameter of the energy transmission coil 1, the coupling area S of the two coils remains unchanged, and the change in magnetic induction intensity is not significant. As can be seen from formula (1), the generated induced electromotive force can be close to 0, and the coupling intensity of the two coils is the weakest. Thus, the structure of the integrated coil 100 of the present invention is designed.

[0043] Figure 3 This is a schematic diagram of the structure of the magnetic near-field coupling wireless signal and power transmission system in an embodiment of the present invention. Figure 4 This is a side view of a magnetic near-field coupled wireless signal transmission system in an embodiment of the present invention.

[0044] like Figure 3 and Figure 4 As shown, a magnetic near-field coupled wireless signal transmission system 200 of this embodiment includes a transmitter integrated coil 10 and a receiver integrated coil 20.

[0045] The transmitter integrated coil 10 includes a transmitter energy transmission coil 11 and a transmitter information transmission coil 12 disposed within the transmitter energy transmission coil 11. The transmitter information transmission coil 12 includes two mutually perpendicularly arranged first DDP coils 121 and second DDP coils 122.

[0046] The receiver integrated coil 20 is positioned opposite the transmitter integrated coil 10 and includes a receiver energy transmission coil 21 and a receiver information transmission coil 22 disposed within the receiver energy transmission coil 21. The transmitter information transmission coil 12 includes two mutually perpendicularly arranged third DDP coils 221 and fourth DDP coils 222.

[0047] The transmitting integrated coil 10 and the receiving integrated coil 20 are of equal size and have symmetrical structures.

[0048] In this embodiment, the first DDP coil 121 and the third DDP coil 221 form one set of information transmitting and receiving coils, and the second DDP coil 122 and the fourth DDP coil 222 form another set of information transmitting and receiving coils. When the transmitting end integrated coil 10 and the receiving end integrated coil 20 are completely aligned, the magnetic flux excited by the transmitting coil and passing through the receiving coil is:

[0049]

[0050] Then the mutual inductance M is:

[0051]

[0052] When the disk-shaped energy transmission coil is energized, it can be determined by the right-hand screw rule that most of the magnetic field generated by the coil is along the Z-axis and perpendicular to the XOY plane.

[0053] DDP coils have two basic excitation methods: in-phase excitation and out-of-phase excitation. Figure 5 This is a schematic diagram of the magnetic field distribution of the DDP coil under different excitations in an embodiment of the present invention.

[0054] like Figure 5 As shown, Figure 5 (a) is a schematic diagram of the magnetic field distribution of the in-phase excitation DDP coil. Figure 5 (b) is a schematic diagram of the magnetic field distribution of the anti-phase excitation DDP coil. When excited in phase, most of the magnetic field direction in the central region of the coil is perpendicular to the XOY plane; when excited in reverse phase, most of the magnetic field direction in the central region of the coil is parallel to the XOY plane. As can be seen from formulas (2) and (3), when the DDP coil adopts the anti-phase excitation method, the mutual inductance between the energy channel and the information channel is approximately 0, and the energy transmission coil is decoupled from each group of DDP coils.

[0055] Figure 6 This is a schematic diagram of the magnetic field distribution of four sets of mutually perpendicular reverse-excitation DDP coils in an embodiment of the present invention.

[0056] like Figure 6 As shown, in the XOY plane, the first DDP coil 121 and the second DDP coil 122 are arranged perpendicularly, as are 221 and 222. When both the first DDP coil 121 and the second DDP coil 122 are subjected to reverse excitation, most of the magnetic field direction in the central region of the first DDP coil 121 and the third DDP coil 221 is parallel to the X-axis, and most of the magnetic field direction in the central region of the second DDP coil 122 and the fourth DDP coil 222 is parallel to the Y-axis. Therefore, the mutual inductance between the first DDP coil 121 and the second DDP coil 122 is close to zero. There is a large transmission distance between the first DDP coil 121 and the fourth DDP coil 222, and the coupling effect between the two coils is weaker and the mutual inductance is smaller than that between the first DDP coil 121 and the second DDP coil 122, which can be ignored. Similarly, the mutual inductance between the second DDP coil 122 and the third DDP coil 221 can also be ignored. Therefore, the coupling relationship of the signal coils mainly consists of two sets of couplings: the first DDP coil 121 and the third DDP coil 221, and the second DDP coil 122 and the fourth DDP coil 222, which realizes enhanced wireless communication.

[0057] This embodiment of a near-field coupled wireless signal-to-power transmission method employs a magnetic near-field coupled wireless signal-to-power transmission system 200 for signal-to-power transmission, including:

[0058] Energy and information transmission between the transmitting integrated coil 10 and the receiving integrated coil 20 occur synchronously.

[0059] During energy transmission, the energy transmission coil 11 at the transmitting end and the energy transmission coil 21 at the receiving end are connected by magnetic coupling wireless power transmission with double-sided series compensation to complete the energy transmission.

[0060] Figure 7 This is an equivalent circuit diagram of energy transmission in an embodiment of the present invention.

[0061] like Figure 7 As shown, according to KVL:

[0062]

[0063] In formula (4), ω is the resonant frequency, R1 and R2 are the coil resistances of the transmitting end energy transmission coil 11 and the receiving end energy transmission coil 21, respectively. s RL is the internal resistance of the power supply, M is the load resistance, and M is the mutual inductance between the transmitting and receiving coils.

[0064] The system's transmission efficiency is maximized when the equivalent impedance of the circuit is purely resistive. At this point, the transmitting and receiving circuits satisfy the following conditions:

[0065]

[0066] The output power P of the WPT system L The transmission efficiency η is as follows:

[0067]

[0068]

[0069] During information transmission, the modulated signal is first loaded onto the transmitting end information transmission coil 12 via amplitude shift keying, then the signal is transmitted to the receiving end information transmission coil 22 via a high-frequency magnetic field, and finally the induced voltage of the receiving end information transmission coil 22 is filtered and demodulated to complete the signal transmission.

[0070] In this embodiment, signal transmission is based on energy modulation technology, which modulates the signal onto the energy waveform. The energy coupling mechanism receives the electrical energy information flow with signal characteristics, and completes information demodulation through the information flow characteristics to complete information transmission.

[0071] Figure 8 This is the signal modulation method in the embodiments of the present invention.

[0072] like Figure 8 As shown, Figure 8 (a) is a schematic diagram of amplitude shift keying principle. Figure 8(b) is a schematic diagram of the OOK principle. The current modulation methods mainly include amplitude shift keying and OOK. Since the OOK method is easy to implement and has obvious waveform characteristics, the OOK modulation method is adopted in this embodiment.

[0073] Figure 9 This is an equivalent circuit diagram of information modulation and demodulation in an embodiment of the present invention.

[0074] like Figure 9 As shown, the modulation and demodulation process of the information is as follows: Signal modulation is achieved by controlling the on / off state of the switch before the inverter circuit via a serial data stream. Simultaneously, the induced sinusoidal voltage is detected at the signal pickup end to complete signal demodulation. When the signal to be transmitted is high, the switch is in the on state, and the circuit operating frequency is the resonant frequency of inductors Lr and Cr. This generates a high-frequency sinusoidal current in the transmitting coil. Based on the principle of electromagnetic induction, the receiving end generates an induced current of the same frequency. After passing through a compensation capacitor, a sinusoidal voltage with a certain amplitude is output. This sinusoidal voltage is the carrier wave carrying the signal to be transmitted. When the signal to be transmitted is low, there is no energy flow in the transmission channel, and the pickup end receives a signal carrier wave with an amplitude of 0. The on / off state of the switch is controlled by the high / low level of the signal to be transmitted, loading the signal onto the carrier wave. The magnetic coupling mechanism transmits the carrier wave to the pickup end through an alternating magnetic field. Then, the carrier wave with information characteristics is demodulated using noncoherent demodulation. First, the voltage at the pickup end is envelope detected. Then, the detected voltage is passed through a low-pass filter to filter out interference from high-frequency harmonics. Finally, the amplitude of the comparator is set, and the carrier wave with amplitude changes is extracted by the comparator for signal demodulation, thereby realizing information communication from the primary end to the secondary end.

[0075] Figure 10 This is a waveform diagram of the signal modulated and demodulated in an embodiment of the present invention.

[0076] like Figure 10 As shown, the transmitted signal is the binary signal to be sent, U1 is the envelope detection voltage, U2 is the filter voltage, and the received signal is the demodulated binary output.

[0077] In this embodiment, experiments were conducted in the simulation software Maxwell according to the integrated coil structure parameters shown in Table 1, and the mutual inductance values ​​between each group of coils were obtained as shown in Table 2.

[0078] Table 1 Integrated coil structure parameters of this embodiment

[0079]

[0080]

[0081] Table 2 Mutual inductance values ​​between coils

[0082]

[0083] Table 2 shows that the maximum mutual inductance between the energy transmission coil and the DDP coil is 12nH, accounting for only 0.1% of the mutual inductance between energy channels, thus completing the cross-decoupling between the energy channel and the information channel. The mutual inductance between the first DDP coil 121 and the second DDP coil 122 is 15nH, accounting for only 1.4% of the mutual inductance between the first DDP coil 121 and the third DDP coil 221, thus completing the mutual decoupling between the information channels.

[0084] To further verify that the integrated coil designed in this invention has good decoupling capability, a comparative experiment was conducted using an undecoupled integrated coil. Figure 11 The images shown are physical diagrams of two integrated coils used in embodiments of the present invention.

[0085] like Figure 11 As shown, Figure 11 (a) shows an integrated coil structure that is not decoupled. Figure 11 (b) The integrated coil structure designed in this invention. Considering the skin effect and eddy current effect under high-frequency magnetic fields, 400 strands of Litz wire are selected for winding. The parameters of the undecoupled integrated coil are shown in Table 3.

[0086] Table 3 Structural parameters of the undecoupled integrated coil

[0087]

[0088] In this embodiment, a 300W wireless charging power is also constructed using a disk-shaped energy transmission coil. Figure 12 This is a wireless power simulation diagram of a disc-shaped power transmission coil in an embodiment of the present invention.

[0089] like Figure 12 As shown, simulations were performed using the WPT analysis software of a vector network analyzer (Keysight E5061B). The input voltage of the wireless charging system was 18V, the output load was 10, and the transmission distance between the transmitting coil and the receiving coil was 60mm. Frequency scanning using the vector network analyzer showed that the frequency of the maximum power point of the wireless charging system built with only a disc-shaped energy transmission coil was 86.5kHz.

[0090] Figure 13 The diagram shows the wireless power simulation of two integrated coils in the embodiments of the present invention.

[0091] like Figure 13 As shown, Figure 13 (a) is a wireless power simulation diagram of an undecoupled integrated coil. Figure 13(b) is a wireless power simulation diagram of the decoupled integrated coil of the present invention. In the undecoupled integrated coil, because the energy transmission coil and information transmission coil are not decoupled, there is cross-interference between the energy channel and the information channel. The self-inductance of the energy transmission coil changes under interference, thus changing the frequency of the resonant point. The system's transmission power at 86.5 kHz decreases from 364 W to 222 W, a reduction of 39%. In contrast, in the decoupled integrated coil of the present invention, the mutual inductance between the energy transmission coil and the information transmission coil is negligible, and the information transmission coil also acts as a magnetic conductor. The system reaches a maximum transmission power of 374 W at 86.5 kHz. Therefore, the decoupled integrated coil of the present invention is suitable for parallel signal and power transmission systems. Thus, the magnetic near-field coupled wireless signal and power transmission system 200 constructed using the integrated coil 100 of the present invention not only achieves cross-decoupling between the information transmission coil and the energy transmission coil on both the transmitting and receiving sides during parallel energy and signal transmission, but also achieves mutual decoupling of the information transmission coil itself on one side, thereby reducing cross-interference between the energy channel and the information channel.

[0092] The role and effect of the embodiments

[0093] According to the integrated coil involved in this embodiment, by utilizing a hollow region with low magnetic induction intensity inside a disk-shaped energy transmission coil and placing the information transmission coil inside the energy transmission coil, the cross-interference between the energy channel and the information channel can be weakened, achieving efficient integration. Furthermore, according to the integrated coil structure designed in this embodiment, the information transmission coil consists of two vertically stacked DDP coils, which can realize enhanced magnetic near-field coupling wireless communication. The two D coils in each DDP coil are excited in opposite directions to generate a polarized magnetic field, thereby decoupling from the outer disk energy transmission coil. At the same time, the two DDP coils are arranged vertically, which can achieve mutual decoupling. Furthermore, the magnetic near-field coupled wireless signal and power transmission system of this embodiment consists of two integrated coils serving as the transmitting and receiving ends, respectively. This not only enables cross-decoupling of the information transmission coils and energy transmission coils on both the transmitting and receiving sides during parallel energy and signal transmission, but also achieves mutual decoupling of the information transmission coils on each side. It also enables miniaturization and integration of the wireless signal and power transmission system structure. Moreover, each module of the magnetic near-field coupled wireless signal and power transmission system of this embodiment operates independently, solving the problem of reduced wireless power transmission power caused by frequency division multiplexing, and has immediacy, without the excessively long matching time of traditional information transmission.

[0094] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. An integrated coil, characterized by, Comprising: an energy transmission coil for energy transmission and an information transmission coil for information transmission arranged in the energy transmission coil, wherein the information transmission coil is composed of two DDP coils arranged vertically and stacked, and the two DDP coils are decoupled by being arranged perpendicularly to each other, two D coils in each of the DDP coils are excited in opposite directions to generate a polarization magnetic field to decouple with the energy transmission coil outside.

2. The integrated coil according to claim 1, wherein: wherein the energy transmission coil is disc-shaped.

3. A magnetic near field coupling type wireless power transfer system using the integrated coil according to claim 1, characterized by, Comprising: a transmitting end integrated coil comprising a transmitting end energy transmission coil and a transmitting end information transmission coil arranged in the transmitting end energy transmission coil, a receiving end integrated coil arranged opposite to the transmitting end integrated coil, comprising a receiving end energy transmission coil and a receiving end information transmission coil arranged in the receiving end energy transmission coil, wherein the transmitting end integrated coil and the receiving end integrated coil are equal in size and symmetrical in structure.

4. A method for magnetic near field coupling wireless power transfer, characterized by, The magnetic near-field coupling type wireless signal and energy transmission system according to claim 3 is used for signal and energy transmission, comprising: the energy transmission and the information transmission between the transmitting end integrated coil and the receiving end integrated coil are performed synchronously, when the energy transmission is performed, the energy transmission between the transmitting end energy transmission coil and the receiving end energy transmission coil is completed by using the magnetic coupling type wireless electric energy transmission with double-sided series compensation, when the information transmission is performed, the modulated signal is first loaded to the transmitting end information transmission coil by amplitude shift keying, then the signal is transmitted to the receiving end information transmission coil by high-frequency magnetic field, and finally the signal transmission is completed by filtering and demodulating the induced voltage of the receiving end information transmission coil.

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