Wireless coupling energy transfer coil anti-offset system and method based on magnetic integration

Abstract

The invention discloses a wireless coupling energy transfer coil anti-offset system and method based on magnetic integration, the system comprises a primary side compensation circuit, a transmitting coil, a receiving coil Ls and a secondary side compensation circuit which are arranged between a system primary side and a system secondary side, and the primary side compensation circuit comprises a primary side compensation inductor LT, a primary side parallel compensation capacitor CT and a primary side series compensation capacitor Cp; the secondary side compensation circuit comprises a secondary side compensation inductor L2, a secondary side parallel compensation capacitor C2 and a secondary side series compensation capacitor Cs; the transmitting coil comprises an energy transmitting sub-coil Lp arranged on the primary side slip ring and an integrated reverse series coil Lf; and the secondary side compensation inductor L2 and the receiving coil Ls are integrally arranged on the secondary side slip ring. According to the invention, the anti-offset characteristic of the wireless slip ring system is effectively improved in a targeted manner by introducing the transmitting coil which is connected in series reversely and the receiving coil integrated with the resonant inductor into the bilateral LCC topology.

Description

Technical Field

[0001] This invention belongs to the field of downhole wireless power transmission technology, specifically relating to a magnetically integrated wireless coupling power transfer coil anti-deflection system and method. Background Technology

[0002] In the oil drilling and production field, downhole operations are often accompanied by extreme conditions such as high temperature, high pressure, and severe vibration, which places higher demands on the durability of slip ring devices. Conventional contact slip rings are prone to abnormal brush wear and sudden changes in contact resistance under frequent start-stop and dynamic load conditions, which may lead to power outages or signal distortion, ultimately jeopardizing drilling efficiency and safety.

[0003] Wireless slip ring systems have emerged as a potential solution to this problem due to their advantages such as non-contact operation, high reliability, and adaptability to metallic environments. This system utilizes the principle of magnetic field coupling to achieve energy transfer between rotating components, avoiding the wear problems caused by physical contact. Furthermore, the magnetic field can penetrate non-metallic media, adapting to complex media environments such as mud. However, conventional wireless slip rings are prone to circuit detuning, output power fluctuations, and even hardware damage under equipment offset conditions. Their weak anti-offset capability has become a major obstacle to the widespread adoption of this technology. Particularly in typical application scenarios such as the dynamic rotation of oil drill pipes, radial offset, axial displacement, and angular deflection of the drill pipe during drilling can cause a sharp drop in magnetic coupling efficiency. This leads to a drastic decrease in the system coupling coefficient, resulting in a sharp reduction in output power. In more severe cases, it can even cause resonant frequency mismatch, causing inverter overload or damage to power devices. Summary of the Invention

[0004] This invention addresses the problem in the prior art where the output characteristics and efficiency of a wireless slip ring change significantly due to the relative offset between the transmitting and receiving coils in the coupler during operation. The purpose is to provide a magnetically integrated anti-offset system and method for wireless coupling power transfer coils.

[0005] This invention is achieved through the following technical solution: A magnetically integrated wireless coupling power transfer coil anti-offset system includes a primary-side compensation circuit disposed between the primary and secondary sides of the system, a transmitting coil, and a receiving coil L. s And the secondary-side compensation circuit, wherein the primary-side compensation circuit consists of the primary-side compensation inductor L T Primary-side parallel compensation capacitor C T The primary-side series compensation capacitor C p The LCC resonant topology is composed of a secondary compensation circuit consisting of a secondary compensation inductor L2, a secondary parallel compensation capacitor C2, and a secondary series compensation capacitor C. sThe structure comprises an LCC resonant topology; the transmitting coil includes an energy transmitting sub-coil L disposed on the primary slip ring. p and the integrated anti-series coil L f The secondary compensation inductor L2 and the receiving coil L s It is integrated on the secondary slip ring.

[0006] In the above technical solution, the energy emitting sub-coil L p With receiving winding L s The corresponding coil is wound using a loosely spiral tube with equal turn spacing; the anti-series coil L f The secondary compensation inductor L2 is wound in a tightly spiral tube with equal turn spacing.

[0007] In the above technical solution, the primary slip ring and the secondary slip ring are a pair of concentrically arranged hollow cylinders, namely the transmitting coil and the receiving coil L. s It is wound around a pair of concentric hollow cylinders.

[0008] In the above technical solution, the primary side of the system includes a DC power supply and a high-frequency inverter, and the high-frequency inverter is connected to the primary side compensation circuit; the secondary side of the system includes a rectifier and filter circuit and an electrical load, and the rectifier and filter circuit is connected to the secondary side compensation circuit.

[0009] In the above technical solution, the primary side and the secondary side of the system have offset space along the axial direction.

[0010] In the above technical solution, the value of the intermediate variable of the anti-offset system of the magnetically integrated wireless coupling power transfer system is configured to be constant; The expression for the intermediate variable is as follows (1): ...(1) In formula (1): As an intermediate variable, For anti-series coil L f With receiving winding L s Mutual intuition between them For energy transmitting sub-coil L p With receiving winding L s Mutual intuition between them For receiving winding L s Mutual inductance between the secondary compensation inductor L2 and the secondary side. This is the system's operating angular frequency.

[0011] In the above technical solution, the primary-side compensating inductor L T Primary-side parallel compensation capacitor C T With equivalent inductance The resonance relationship shown in equation (3) is maintained between them through parameter configuration; The equivalent inductance The definition is as follows (2): ...(2) In the formula: For energy transmitting sub-coil L p With anti-series coil L f Mutual intuition between them, L p For the energy emitting sub-coil, L f For anti-series coils, C p This is a primary-side series compensation capacitor. This refers to the system's operating angular frequency; The primary-side compensation inductor L T Primary-side parallel compensation capacitor C T With equivalent inductance The resonance relationship between them is: ... (3) In the formula: This is the system's operating angular frequency.

[0012] In the above technical solution, the secondary-side compensation inductor L2, the secondary-side parallel compensation capacitor C2, and the secondary-side series compensation capacitor C s and receiving winding L s The resonance relationship shown in equation (4) is maintained between them through parameter configuration; ... (4) In the formula: This is the system's operating angular frequency.

[0013] A method for mitigating offset in a magnetically integrated wireless coupled power transfer system is proposed, employing the aforementioned magnetically integrated anti-offset system for wireless coupled power transfer, where the system is configured as an intermediate variable M. eq The value is constant, and the output current depends only on the input voltage, exhibiting a constant current output characteristic independent of the load.

[0014] The beneficial effects of this invention are: This invention provides a magnetically integrated wireless coupling power transfer coil anti-offset system and method. The circuit is constructed based on a bilateral LCC resonant network. An anti-reverse series coil is integrated inside the coupler's transmitting coil, and a resonant inductor coil is integrated inside the receiving coil. A stable equivalent mutual inductance is established between the receiving coil and the transmitting coil, thereby effectively improving the anti-offset characteristics of the wireless slip ring system. Attached Figure Description

[0015] Figure 1 This is a topological diagram of the present invention; Figure 2 This is the circuit mutual inductance equivalent model of the present invention; Figure 3 This is a schematic diagram of the spatial helical coil winding method in this invention; Figure 4 This is a schematic diagram of the coupler structure in this invention; Figure 5 This is a schematic diagram of the primary slip ring in this invention; Figure 6 This is a schematic diagram of the structure of the secondary slip ring in this invention; Figure 7 This is the output current diagram with a relative offset of 0~6cm in Embodiment 1 of the present invention; Figure 8 This is the load output waveform diagram from the simulation experiment; Figure 9 This is the simulated output current waveform after offset; Figure 10 This is a simulated input current waveform after offset.

[0016] Figure 1 middle: It is the AC output voltage of the high-frequency inverter; It is the output voltage of the secondary-side compensation circuit; It is a resistive load equivalent to a load. It is an energy-emitting sub-coil; L f It is an anti-series coil; Ls is the receiving winding; L2 is the secondary compensation inductor; L T It is the primary-side compensating inductor; C T It is a primary-side parallel compensation capacitor; C p C1 is the primary-side series compensation capacitor; C2 is the secondary-side parallel compensation capacitor; C s C0 is the secondary-side series compensation capacitor; C0 is the rectifier output filter capacitor. , , , , , The mutual inductance between the coils corresponds to the mutual inductance between each coil; ω is the system operating angular frequency. ~ It is the MOSFET of the inverter; ~ It is a diode in a rectifier filter circuit.

[0017] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1 like Figure 1 As shown, a magnetically integrated wireless coupling power transfer coil anti-offset system includes a primary-side compensation circuit disposed between the primary and secondary sides of the system, a transmitting coil, and a receiving coil L. s And the secondary-side compensation circuit, wherein the primary-side compensation circuit consists of the primary-side compensation inductor L T Primary-side parallel compensation capacitor C T The primary-side series compensation capacitor C p The LCC resonant topology is composed of a secondary compensation circuit consisting of a secondary compensation inductor L2, a secondary parallel compensation capacitor C2, and a secondary series compensation capacitor C. s The structure comprises an LCC resonant topology; the transmitting coil includes an energy transmitting sub-coil L disposed on the primary slip ring. p and the integrated anti-series coil L f The secondary compensation inductor L2 and the receiving coil L s It is integrated on the secondary slip ring.

[0020] A method for mitigating drift in a magnetically integrated wireless coupled power transfer system, based on the system described above, involves configuring the system as follows: The constant value means that the output current depends only on the input voltage, thus exhibiting a constant current output characteristic independent of the load.

[0021] The coupler structure used in the system can be as follows: Figures 4-6 As shown, the integrated transmitting and receiving coils are wound on a pair of concentric hollow cylinders, which is a nested non-contact slip ring structure in the common rotary slip ring coupler in MC-WPT. It has a transmitting end and a receiving end that rotate relative to each other. Its advantages are that it can improve the coil coupling coefficient, reduce the air gap, reduce the system eddy current loss, avoid the wear caused by physical contact of traditional slip rings, and reduce EMI.

[0022] The energy emitting sub-coil L p With receiving winding L s All are wound using a loosely spiral tube with equal turn spacing; the anti-series coil L f Both the secondary compensation inductor L2 and the coils are wound using a tightly wound helical coil with equal turn spacing. In specific implementation, the coil winding method is as follows: Figure 3 As shown, in the coupler , The corresponding windings adopt a loose winding with equal turn spacing. , The corresponding coil is wound relatively tightly, with a small spacing between each turn of the conductor; The primary side of the system includes a DC power supply and a high-frequency inverter, which is connected to the primary side compensation circuit; the secondary side of the system includes a rectifier and filter circuit and an electrical load, which is connected to the secondary side compensation circuit; the primary side and the secondary side of the system have offset space along the axial direction.

[0023] The intermediate variable values ​​of the magnetically integrated wireless slip ring anti-offset system are configured to be constant, so that the output current depends only on the input voltage, exhibiting a constant current output characteristic independent of the load. The expression for the intermediate variable is as follows (1): ...(1) In formula (1): As an intermediate variable, For anti-series coil L f With receiving winding L s Mutual intuition between them For energy transmitting sub-coil L p With receiving winding L s Mutual intuition between them For receiving winding L s Mutual inductance between the secondary compensation inductor L2 and the secondary side. for Figure 1 The operating angular frequency of the offset-resistant system in the magnetically integrated wireless coupling power transfer system is shown.

[0024] The primary-side compensation inductor L T Primary-side parallel compensation capacitor C T With equivalent inductance The resonance relationship shown in Equation (3) is maintained between them through parameter configuration (adjustment of inductor and capacitor parameters in Equation 3); The equivalent inductance The definition is as follows (2): ...(2) In the formula: For energy transmitting sub-coil L p With anti-series coil L f Mutual intuition between them, L p For the energy emitting sub-coil, L f For anti-series coils, C p This is a primary-side series compensation capacitor. This refers to the system's operating angular frequency; The primary-side compensation inductor L T Primary-side parallel compensation capacitor C T With equivalent inductance The resonance relationship between them is: ... (3) In the formula: This is the system's operating angular frequency.

[0025] The primary-side compensation inductor L T Primary-side parallel compensation capacitor C T With equivalent inductance The resonance relationship between them is: The secondary-side compensation inductor L2, the secondary-side parallel compensation capacitor C2, and the secondary-side series compensation capacitor C s and receiving winding L s The resonance relationship shown in equation (4) is maintained between them through parameter configuration (adjustment of inductor and capacitor parameters in equation 4); ... (4) In the formula: This is the system's operating angular frequency.

[0026] To verify that the system can achieve a stable output current, the system's input and output characteristics are analyzed using a circuit model.

[0027] In addition to the aforementioned equivalent inductance In addition to the definition of , the following equation (5) is defined to simplify the calculation process: ... (5) Based on the above equivalent definition Figure 1 The equivalent model of mutual inductance in a circuit is as follows: Figure 2 As shown: Based on the fundamental wave analysis method and Kirchhoff's voltage law, Figure 2 For the simultaneous equations, the circuit relationship can be expressed as equation (6): ... (6) , , resonance, , , and The equivalent inductance resonance is expressed by equation (7): ... (7) By substituting (7) into (6), it can be simplified to equation (8): ... (8) Solving equation (8) yields the input voltage. and output current The relationship is given by equation (9): ... (9) Formula (9) illustrates that after the circuit parameters are determined, The value is constant, and the output current depends only on the input voltage, exhibiting constant current output characteristics independent of the load.

[0028] In this embodiment, the coupler input voltage is fixed at 60V, the operating frequency is fixed at 85kHz, and the target output current is 5A. Electromagnetic simulation is performed according to the simulation parameters in Table 1.

[0029] Table 1: Electromagnetic Simulation Parameter Values The offset value is set to a range of 0~6cm. After simulation, the parameters are substituted into formula (9). After data processing, we have: Figure 7 Output current and relative offset diagram. The results show that when the offset is ≤6cm, the relative offset of the output current of the optimized coupler is within ±5%, and the system can maintain good anti-offset performance, meeting the expected design requirements.

[0030] In summary, the simulation results of Maxwell 3D show that when the designed coupler adopts the parameter values ​​in Table 1, the theoretical output of the system is 6.22A, and when the wireless slip ring system coupler is offset within ±6cm in the axial direction, the output current offset is within ±5%, which meets the expected anti-offset design requirements.

[0031] After completing the Maxwell 3D simulation, the coupler parameters without offset are shown in Table 2.

[0032] Table 2: Coupler Parameter Table Other model parameters in Simulink can be calculated using the resonance relation formula (7). The specific model parameter values ​​are shown in Table 3.

[0033] Table 3 Simulink simulation parameter values Where the coupler M1 = μH.

[0034] Circuit simulation was performed based on the simulation parameters in Tables 2 and 3. After the load current stabilized for a period of time, the equivalent load resistance was changed. Figure 8 Simulation model load output waveform diagram.

[0035] Simulation results show that when the equivalent load changes, the output current... It can still maintain a stable 5A, demonstrating a stable output current characteristic unaffected by load.

[0036] Circuit simulation was performed under different offset conditions by changing the value of the coupler parameter M to verify the anti-offset performance.

[0037] M2= μH is the coupler parameter with a vertical offset of ±3cm. M3= μH is the coupler parameter with a vertical offset of ±6cm. Simulation was performed while keeping other parameters in the model constant. The system output current was as follows as the offset changed from 0cm to 6cm, then to 0cm, and finally to -6cm: Figure 9 As shown.

[0038] The output current value is 4.805A for ±3cm offset and 4.89A for ±6cm offset.

[0039] The RMS value of the inverter output current (system input current) after offset is as follows: Figure 10 As shown.

[0040] The RMS value of the input current with a ±3cm offset is 2.263A, and the RMS value of the input current with a ±6cm offset is 2.353A.

[0041] Comparing the output current and system efficiency before and after the offset, we have: When the offset is 3cm, the relative current offset is the largest, the system input current is 2.263A, the output current is 4.805A, the relative current offset is 3.82%, and the theoretical system efficiency is 85.02%. When the offset is 6cm, the coupler has the largest relative displacement, the system input current is 2.353A, the output current is 4.890A, the relative current offset is 2.12%, and the theoretical system efficiency is 84.69%. Based on the above simulations, the designed magnetically integrated wireless coupling power transfer system achieves a stable output of current unaffected by the load. =5A. When the primary and secondary coils of the coupler do not experience relative misalignment, the theoretical transmission efficiency of the system reaches 87.69%; even with a misalignment within ±6cm, it can still maintain stable output current characteristics, and the output current is compared to... The offset is within ±5%, exhibiting good anti-offset performance, and the theoretical transmission efficiency of the system after offset is still above 84%.

[0042] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A magnetic integration based wireless coupling power transfer coil anti-offset system, comprising a primary side compensation circuit, a transmitting coil, a receiving coil L s and a secondary side compensation circuit arranged between a system primary side and a system secondary side, characterized in that: The primary side compensation circuit is an LCC resonant topology structure composed of a primary side compensation inductor L T , a primary side parallel compensation capacitor C T , and a primary side series compensation capacitor C p ; the secondary side compensation circuit is an LCC resonant topology structure composed of a secondary side compensation inductor L2, a secondary side parallel compensation capacitor C2, and a secondary side series compensation capacitor C s ; the transmitting coil includes an energy transmitting sub-coil L p and an anti-series coil L f provided on the primary side slip ring; and the secondary side compensation inductor L2 and the receiving coil L s are provided on the secondary side slip ring.

2. The magnetic integration based wireless coupling power transfer coil anti- misalignment system of claim 1, wherein: The energy emitting sub-coil L p The receiving coil L s Both are wound in the form of equal-turn loose solenoid pipe; the anti-series coil L f Both the secondary side compensation inductance L2 are wound in the form of equal-turn tight solenoid pipe.

3. The magnetic integration based wireless coupling power transfer coil misalignment tolerant system of claim 1, wherein: The primary side slip ring and the secondary side slip ring are a pair of hollow cylinders arranged concentrically.

4. The magnetic integration based wireless coupling power transfer coil misalignment tolerant system of claim 1, wherein: The primary side of the system comprises a direct current power supply and a high-frequency inverter, and the high-frequency inverter is connected with the primary side compensation circuit; the secondary side of the system comprises a rectification filtering circuit and a power consumption load, and the rectification filtering circuit is connected with the secondary side compensation circuit.

5. The magnetic integration based wireless coupling power transfer coil anti- misalignment system of claim 1, wherein: The primary side of the system and the secondary side of the system have a deviation space along an axial direction.

6. The magnetic integration based wireless coupling power transfer coil anti- misalignment system of claim 1, wherein: The value of the intermediate variable of the anti-deviation system of the wireless coupling energy transmission system based on magnetic integration is configured to be constant; An expression of the intermediate variable is as follows: ……（1） In formula (1): As an intermediate variable, For anti-series coil L f With receiving winding L s Mutual intuition between them Energy emitter coil L p With receiving winding L s Mutual intuition between them For receiving winding L s Mutual inductance between the secondary compensation inductor L2 and the secondary side. This is the system's operating angular frequency.

7. The magnetic integration based wireless coupling power transfer coil anti- misalignment system of claim 1, wherein: The primary side compensation inductor L T , the primary side parallel compensation capacitor C T and the equivalent inductance maintain the resonance relationship shown in equation (3). the equivalent inductance The definition formula is as follows (2): ……（2） wherein: L is the energy transmitting sub-coil p L is the mutual inductance between the anti-series coil f L is the mutual inductance between the anti-series coil p L is the energy transmitting sub-coil f L is the energy transmitting sub-coil p C is the primary series compensation capacitor, ω is the system operating angular frequency; The primary side compensation inductor L T , the primary side parallel compensation capacitor C T and the equivalent inductance between the resonance relationship is: ……（3） In the formula: is the system angular frequency of operation.

8. The magnetic integration based wireless coupling power transfer coil anti- misalignment system of claim 1, wherein: The secondary side compensation inductor L2, the secondary side parallel compensation capacitor C2, the secondary side series compensation capacitor C s and the receiving coil L s maintain the resonance relationship shown in the following formula (4); ……（4） In the formula: is the system angular frequency.

9. A magnetic integration based anti-offset method for wireless coupling power transfer coils, characterized in that: The magnetic integration based wireless coupling energy transfer coil anti-offset system of any one of claims 1-8, the system is configured as an intermediate variable M eq The value is constant, and the output current only depends on the input voltage, which is represented as a constant current output characteristic independent of the load.

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