Wireless power supply circuit for use in oil and water wells and method of commissioning thereof

Abstract

The application provides a wireless power supply circuit for oil-water well and a debugging method thereof. The circuit comprises a high-frequency signal generating circuit, a two-way signal driving circuit, an inverter switch circuit, a coupling coil, a full-bridge rectification filter circuit and a load. The high-frequency signal generating circuit generates high-frequency signals and can adjust the frequency and duty cycle of the high-frequency signals. The two-way signal driving circuit converts the high-frequency signals generated by the high-frequency signal generating circuit into two-way control signals with opposite phases, which are used for driving control of the inverter switch circuit. The inverter switch circuit converts direct current into high-frequency alternating current under the control of the two-way control signals with opposite phases. The coupling coil emits the high-frequency alternating current to the oil-water space in the well. The full-bridge rectification filter circuit converts the high-frequency alternating current received by the coupling coil into direct current and transmits the direct current to the load. The application can realize efficient and high-power supply for the intelligent equipment in the well under special environment and realize use as charging.

Description

Technical Field

[0001] This invention relates to the field of downhole communication circuit technology in oil extraction, and in particular to a wireless power supply circuit for downhole oil and water wells and its debugging method. Background Technology

[0002] In the process of oil extraction, the application of intelligent monitoring and control technology in oil-water environments is inseparable from a stable power supply. With the advancement of downhole monitoring and control technology from wired to wireless, wireless power supply technology has become the foundation for the development of monitoring and control technology. Currently, most downhole wireless power supplies use electromagnetic coupling combined with high-frequency signal generation circuits. However, with the changing downhole oil-water environment under different well conditions, the key to downhole wireless power supply lies in how to generate variable-frequency AC power through hardware circuits to achieve electromagnetic coupling resonance and maximize power transmission efficiency. Existing technologies mostly use fixed hardware circuits combined with software programming to generate PWM waves of different frequencies to produce electromagnetic waves. This approach consumes CPU time, reducing system efficiency, and requires rewriting and reprogramming to adjust different frequencies, which is inconvenient for circuit testing and adjustment, reducing the circuit's flexibility and applicability.

[0003] Currently, most downhole wireless power supply systems employ electromagnetic coupling combined with high-frequency signal generation circuits. However, the key to downhole wireless power supply lies in how to generate variable-frequency AC power through hardware circuitry to achieve electromagnetic coupling resonance and maximize power transmission efficiency, given the varying downhole oil and water environments under different well conditions. Existing technologies mostly use fixed hardware circuitry combined with software programming to generate PWM waves of different frequencies to produce electromagnetic waves. This approach consumes CPU time, reducing system efficiency, and requires rewriting and reprogramming to adjust different frequencies, which is inconvenient for circuit testing and adjustment, reducing the circuit's flexibility and applicability.

[0004] Patent CN106411169A relates to a high-frequency signal generation circuit based on digital-to-analog conversion (DAC), including a microprocessor with DAC function. The microprocessor is sequentially connected to a voltage follower circuit, a PWM pulse generation and driving circuit, and a high-frequency transformer. The microprocessor is also connected to a voltage sampling circuit, which is connected to an input DC power supply. This invention utilizes the microprocessor to collect and process the signal, and generates a specific analog voltage through the internal D / A (digital-to-analog converter) circuit of the chip to control the switching chip that generates PWM pulses, thereby adjusting the duty cycle of the PWM pulses, controlling the magnetic saturation of the high-frequency transformer, and reducing the no-load current of the high-frequency inverter.

[0005] Patent CN110149069A discloses a high-efficiency high-frequency signal generation circuit suitable for ground power supply systems in wireless charging of electric vehicles, belonging to the field of wireless power transmission technology. It mainly includes the basic structure and working principle of a high-efficiency high-frequency signal generation circuit using SiC MOSFETs as switching elements, as well as a PFC selection scheme. This invention effectively solves the problem of insufficient efficiency in the ground system of wireless charging systems by replacing the original Si MOSFETs with SiC MOSFETs and employing a power factor correction circuit. Simultaneously, using DSP to control the PWM output can effectively and quickly change the PWM frequency, and a hysteresis (or loop) current control method is used for closed-loop control of the PFC circuit.

[0006] Patent CN107959430A relates to a voltage-type high-frequency signal generation circuit topology. This inverter circuit topology still adopts a bridge structure, with only two switching transistors. The two switching transistors complement each other in turning on and off, and are connected to a common ground. There is no need to isolate the power supplies of the drive circuit, which simplifies the drive circuit. The two drive signals of the switching transistors do not require dead time design. This circuit is applicable to resistive-capacitive load conditions. When the load is purely resistive, the amplitude of the output AC voltage square wave is twice that of the DC voltage. Compared with the traditional bridge inverter circuit, it has stronger output power capability, a simpler drive circuit, and reduced switching losses of the switching transistors.

[0007] The aforementioned comparative patent discloses a high-frequency signal generation circuit based on digital-to-analog conversion, a high-efficiency high-frequency signal generation circuit, and a voltage-type high-frequency signal generation circuit topology. It mainly introduces the wireless power supply circuit topology and system framework, which are different from the circuit structure and function used in this invention.

[0008] The existing technologies described above are significantly different from this invention. A search reveals no literature in the XY category, indicating that this invention is innovative. Since no solution exists in the existing technology to address the technical problem we seek to solve, we have invented a novel wireless power supply circuit for downhole oil and water wells, along with its debugging method. Summary of the Invention

[0009] The purpose of this invention is to provide a wireless power supply circuit and its debugging method for oil and water wells that can provide high-efficiency, high-power power supply to downhole intelligent devices under special environments, enabling on-demand charging.

[0010] The objective of this invention can be achieved through the following technical measures: a wireless power supply circuit for downhole oil and water wells, comprising a high-frequency signal generation circuit, a dual-channel signal drive circuit, an inverter switch circuit, a coupling coil, a full-bridge rectifier filter circuit, and a load. The high-frequency signal generation circuit generates a high-frequency signal and can adjust the frequency and duty cycle of the high-frequency signal. The dual-channel signal drive circuit converts the high-frequency signal generated by the high-frequency signal generation circuit into dual-channel control signals with opposite phases for driving and controlling the inverter switch circuit. Under the control of the dual-channel control signals with opposite phases, the inverter switch circuit converts DC power into high-frequency AC power. The coupling coil transmits the high-frequency AC power to the downhole oil and water space. The full-bridge rectifier filter circuit converts the high-frequency AC power received by the coupling coil into DC power and transmits it to the load.

[0011] The objective of this invention can also be achieved through the following technical measures:

[0012] The high-frequency signal generating circuit includes a pulse width modulation chip and its peripheral circuits. The high-frequency signal generating circuit is externally connected to a first adjustable resistor and a second adjustable resistor. The frequency of the high-frequency signal generated by the pulse width modulation chip can be adjusted by manually adjusting the first adjustable resistor. The duty cycle of the high-frequency signal generated by the pulse width modulation chip can be adjusted by manually adjusting the second adjustable resistor.

[0013] By adjusting the first adjustable resistor and the second adjustable resistor, the high-frequency signal generating circuit generates and outputs two high-frequency signals a and b with opposite phases, with a period of T = T1 + T2 and a duty cycle of T1 / T; and the rising edge of high-frequency signal a and the rising edge of high-frequency signal b differ in time by half a period T / 2; the periods of high-frequency signal a and high-frequency signal b are the same, and their duty cycles are also the same.

[0014] The dual-channel signal drive circuit converts the a and b signals generated by the high-frequency signal generator circuit into a1 and a2, b1 and b2 signals respectively, and then outputs them; the a, a1, and a2 signals are the same, and the b, b1, and b2 signals are the same; the a1, b1, b2, and a2 signals are connected to the four input ports of the inverter switch circuit respectively.

[0015] The coupling coil includes a transmitting coil and a receiving coil. The two ends of the transmitting coil are respectively connected to the two output ports of the inverter switching circuit, and the two ends of the receiving coil are respectively connected to the two input ports of the full-bridge rectifier filter circuit.

[0016] The inverter switching circuit includes a first capacitor, four MOSFETs Q1, Q2, Q3, and Q4, and four bias resistors R1, R2, R3, and R4. The gate of each MOSFET is connected to a device consisting of a diode and a resistor in parallel, so that the MOSFET turns on slowly and turns off quickly, avoiding the simultaneous conduction of MOSFETs on the same side. The first capacitor and the transmitting coil in the coupling coil together form an LC resonant circuit.

[0017] The full-bridge rectifier filter circuit includes a second capacitor, a third capacitor, and a full-bridge rectifier circuit composed of four diodes. The second capacitor and the receiving coil form an LC resonant circuit. The third capacitor is connected in parallel across the load to filter out high-frequency noise and make the voltage applied to the load more stable. The two output terminals of the full-bridge rectifier filter circuit are connected to the load.

[0018] The objective of this invention can also be achieved through the following technical measures: a debugging method for a wireless power supply circuit used in oil and water wells, the debugging method for debugging a wireless power supply circuit used in oil and water wells, comprising:

[0019] Step 1: The high-frequency signal generation circuit generates two high-frequency signals a and b. The duty cycle of high-frequency signal a is adjusted by manually adjusting the second adjustable resistor.

[0020] Step 2: The dual-channel signal drive circuit converts the high-frequency signals a and b into signals a1 and a2, b1 and b2, respectively, and connects them to the four input ports of the inverter switch circuit.

[0021] Step 3: Manually adjust the first adjustable resistor. The output of the inverter switch circuit generates a high-frequency signal with frequency f1 varying with the first adjustable resistor. Test and calculate the power P1 of the transmitting coil and the power P2 of the receiving coil of the coupling coil.

[0022] Step 4: When the ratio of P2 / P1 is at its maximum, stop adjusting the first adjustable resistor, and record the resistance value of the first adjustable resistor and the frequency f1 on the transmitting coil. f1 is the resonant frequency suitable for this oil and water environment.

[0023] Step 5: Record the current load value R1, measure the voltage U3 and current I3 across the load, and calculate the load power P3 = U3 * I3; manually adjust the second adjustable resistor to make the load power P3 reach the power value required by the load; test the waveform of the high-frequency signal a and calculate the duty cycle.

[0024] The objective of this invention can also be achieved through the following technical measures:

[0025] The debugging method for the wireless power supply circuit used in oil and water wells also includes, before step 1, placing the coupling coil in the oil-water mixture and recording the ratio of the oil-water mixture; adjusting the temperature of the oil-water mixture to the temperature of the production well and recording the temperature; and connecting the load and power supply.

[0026] In step 1, the high-frequency signal generating circuit generates two high-frequency signals a and b with opposite phases, with a period of T = T1 + T2 and a duty cycle of T1 / T. The rising edge of high-frequency signal a and the rising edge of high-frequency signal b differ in time by half a period T / 2. The periods and duty cycles of high-frequency signals a and b are the same. Observe high-frequency signal a with an oscilloscope and manually adjust the second adjustable resistor to make the duty cycle of high-frequency signal a less than 50%, i.e., T1 / T < 0.5.

[0027] In step 3, test the voltage U1, current I1 and frequency f1 across the transmitting coil, test the voltage U2, current I2 and frequency f2 across the receiving coil, and calculate the power P1 = U1 * I1 and P2 = U2 * I2.

[0028] The debugging method for the wireless power supply circuit used in oil and water wells also includes, after step 5, recording the oil-water ratio, the duty cycle of the high-frequency signal a, the frequency f1; the resistance value Rp1 of the first adjustable resistor and the resistance value Rp2 of the second adjustable resistor, the transmission efficiency P2 / P1, the load resistance value R1, and the load power P3; the test is completed.

[0029] The wireless power supply circuit and its debugging method for oil and water wells in this invention overcome the shortcomings of existing technologies by proposing a method that uses an adjustable resistor and pulse modulation circuit to generate a real-time adjustable PWM wave, which further drives a high-frequency signal generation circuit to generate radio electromagnetic waves, thereby achieving wireless power supply downhole. Furthermore, a debugging method for the wireless power supply circuit is designed to suit high-temperature and oil-water mixed liquid environments. This circuit is applicable to various oil and water well media and can achieve high-efficiency, high-power power supply to downhole intelligent devices under special environments, enabling on-demand charging and use, and solving the problem of long-term power supply for intelligent devices in the well.

[0030] To meet on-site requirements, this invention provides a wireless power supply circuit and its debugging method for use in oil and water wells. The wireless power supply circuit for oil and water wells comprises four parts: a high-frequency signal generation circuit, a dual-channel signal drive circuit, an inverter switch circuit, and a wireless transmitting coil. The high-frequency signal generation circuit generates a high-frequency signal and can adjust the frequency and duty cycle of this signal at any time. The dual-channel signal drive circuit converts the high-frequency signal generated by the high-frequency signal generation circuit into dual-channel control signals with opposite phases, used to drive and control the inverter switch circuit. The inverter switch circuit converts DC power into high-frequency AC power under the control of the dual-channel control signals with opposite phases. The coupling coil transmits the high-frequency AC power into the downhole oil and water space. The full-bridge rectifier and filter circuit converts the AC power received by the coupling coil into DC power and transmits it to the load.

[0031] Compared with existing technologies, this invention offers several advantages: In wireless power transmission, the generation of PWM waves in high-frequency signal generation circuits typically involves two methods: software implementation and hardware implementation. Software programming outputs PWM waves, meaning software programs output PWM waves from CPU pins and control their frequency and duty cycle. This invention, however, uses hardware circuitry to generate and control PWM waves, saving CPU resources and improving CPU system efficiency. This invention allows for manual adjustment of the PWM wave frequency and duty cycle, making it suitable for flexible applications under different downhole oil and water media conditions. Circuit debugging is simpler and operation is more convenient, eliminating the tedious steps of rewriting and re-implanting software programs compared to software-based PWM wave generation. Furthermore, the testing and control methods for downhole wireless power supply circuits employed in this invention can optimize the selection of wireless power supply circuits more suitable for different downhole media conditions, providing flexibility and expanding the practicality of downhole wireless power supply technology. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a wireless power supply circuit for use in oil and water wells in a specific embodiment of the present invention;

[0033] Figure 2 This is a circuit diagram of an inverter switching circuit in a specific embodiment of the present invention;

[0034] Figure 3 This is a circuit diagram of the coupling coil in a specific embodiment of the present invention;

[0035] Figure 4 This is a circuit diagram of a full-bridge rectifier filter circuit in a specific embodiment of the present invention;

[0036] Figure 5 This is a PWM waveform diagram in a specific embodiment of the present invention. Detailed Implementation

[0037] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0039] This invention relates to a wireless power supply circuit for oil and water wells, comprising six parts: a high-frequency signal generation circuit, a dual-channel signal drive circuit, an inverter switch circuit, a coupling coil, a full-bridge rectifier filter circuit, and a load. The high-frequency signal generation circuit generates a high-frequency signal and can adjust its frequency and duty cycle at any time. The dual-channel signal drive circuit converts the high-frequency signal generated by the high-frequency signal generation circuit into two opposite-phase control signals for driving and controlling the inverter switch circuit. The inverter switch circuit converts DC power into high-frequency AC power under the control of the opposite-phase control signals. The coupling coil transmits the high-frequency AC power into the downhole oil and water space. The full-bridge rectifier filter circuit converts the AC power received by the coupling coil into DC power and transmits it to the load.

[0040] The high-frequency signal generation circuit consists of a pulse width modulation (PWM) chip and its peripheral circuitry, externally connected to two adjustable resistors Rp1 and Rp2. Rp1 is manually adjustable to adjust the frequency of the PWM wave generated by the PWM chip; Rp2 is manually adjustable to adjust the duty cycle of the PWM wave generated by the PWM chip. Figure 5 As shown, a high-frequency signal generation circuit generates and outputs two PWM signals a and b with opposite phases. Their period is T = T1 + T2, and their duty cycle is T1 / T. The rising edge of signal a and the rising edge of signal b differ by half a period T / 2 in time. Signals a and b have the same period and the same duty cycle.

[0041] The dual-signal drive circuit converts the a and b signals generated by the high-frequency signal generation circuit into a1 and a2, b1 and b2 signals, and then outputs them. The a, a1, and a2 signals are the same, and the b, b1, and b2 signals are the same. The a1, b1, b2, and a2 output signals are connected to ports 1, 2, 3, and 4 of the inverter switch circuit.

[0042] The inverter switching circuit includes four MOSFETs Q1, Q2, Q3, and Q4, and four bias resistors R1, R2, R3, and R4. Each MOSFET's gate is connected to a diode and a resistor in parallel; this allows the MOSFET to turn on slowly and turn off quickly, preventing simultaneous conduction of MOSFETs on the same side. Capacitor C1 and the transmitting coil L1 in the next stage coupling coil together form an LC resonant circuit.

[0043] The coupling coil consists of a transmitting coil L1 and a receiving coil L2. Terminals 7 and 8 of coil L1 are connected to the output ports 5 and 6 of the inverter switching circuit, respectively; terminals 9 and 10 of coil L2 are connected to the input ports 11 and 12 of the full-bridge rectifier filter circuit, respectively.

[0044] The full-bridge rectifier filter circuit consists of four diodes. Capacitor C2 and receiving coil L2 form an LC resonant circuit; capacitor C3 is connected in parallel across the load to filter out high-frequency noise and make the voltage applied to the load more stable; the output terminals 13 and 14 of the full-bridge rectifier filter circuit are connected to the load.

[0045] A debugging method for a wireless power supply circuit used in oil and water wells downhole includes:

[0046] Step 1: The high-frequency signal generation circuit generates two high-frequency signals a and b. The duty cycle of high-frequency signal a is adjusted by manually adjusting the second adjustable resistor.

[0047] Step 2: The dual-channel signal drive circuit converts the high-frequency signals a and b into signals a1 and a2, b1 and b2, respectively, and connects them to the four input ports of the inverter switch circuit.

[0048] Step 3: Manually adjust the first adjustable resistor. The output of the inverter switch circuit generates a high-frequency signal with frequency f1 varying with the first adjustable resistor. Test and calculate the power P1 of the transmitting coil and the power P2 of the receiving coil of the coupling coil.

[0049] Step 4: When the P2 / P1 ratio is at its maximum, stop adjusting the first adjustable resistor, record the resistance value of the first adjustable resistor and the frequency f1 on the transmitting coil. f1 is the resonant frequency suitable for this oil-water environment.

[0050] Step 5: Record the current load value R1, measure the voltage U3 and current I3 across the load, and calculate the load power P3 = U3 * I3; manually adjust the second adjustable resistor to make the load power P3 reach the power value required by the load; test the waveform of the high-frequency signal a and calculate the duty cycle.

[0051] Step 6: Record the oil-water ratio, the duty cycle of the high-frequency signal a, the frequency f1; the resistance values ​​Rp1 and Rp2 of the first and second adjustable resistors, the transmission efficiency P2 / P1, the load resistance R1, and the load power P3; the test is complete.

[0052] Existing technologies all employ fixed hardware circuits and software programming to generate PWM waves of different frequencies to produce electromagnetic waves. This approach consumes CPU time, reducing system efficiency, and requires rewriting and reprogramming to adjust different frequencies, which is inconvenient for circuit testing and adjustment, reducing the circuit's flexibility and applicability. This invention, however, allows for pre-testing in a test environment by manually adjusting the PWM wave frequency and duty cycle, maximizing the wireless power transmission efficiency in various oil and water environments. This debugging method is more convenient, and the wireless power supply circuit can be used in a wider range of downhole environments.

[0053] This invention innovatively utilizes the wireless power supply circuit structure, and therefore, in conjunction with this wireless power supply circuit structure, an innovative debugging method for the circuit was invented. This debugging method, by adjusting the resistance values ​​of two resistors and combining them with power testing, ensures that the circuit can operate at maximum transmission efficiency in different environments.

[0054] The following are several specific embodiments of the application of the present invention.

[0055] Example 1: A wireless power supply circuit for oil and water wells downhole

[0056] A wireless power supply circuit for use in oil and water wells: such as Figure 1 As shown, the circuit consists of six parts: a high-frequency signal generation circuit 10, a dual-channel signal drive circuit 20, an inverter switch circuit 30, a coupling coil 40, a full-bridge rectifier and filter circuit 50, and a load 60.

[0057] The high-frequency signal generating circuit 10 is used to generate high-frequency signals, and the frequency and duty cycle of the high-frequency signals can be adjusted at any time.

[0058] The dual-signal drive circuit 20 is used to convert the high-frequency signal generated by the high-frequency signal generation circuit 10 into dual-control signals with opposite phases, which are used to drive and control the inverter switch circuit 30.

[0059] The function of the inverter switch circuit 30 is to convert DC power into high-frequency AC power under the control of dual control signals with opposite phases.

[0060] The coupling coil 40 is used to transmit high-frequency alternating current into the downhole oil and water space.

[0061] The full-bridge rectifier filter circuit 50 is used to convert the AC power received by the coupling coil 40 into DC power and transmit it to the load 60.

[0062] The high-frequency signal generation circuit 10 consists of a pulse width modulation chip (such as SG3525A) and its peripheral circuitry, externally connected to two adjustable resistors Rp1 and Rp2; wherein the manually adjustable resistor Rp1 is used to adjust the frequency of the PWM wave generated by the pulse width modulation chip; the manually adjustable resistor Rp2 is used to adjust the duty cycle of the PWM wave generated by the pulse width modulation chip; such as Figure 5 As shown, a high-frequency signal generation circuit generates and outputs two PWM signals a and b with opposite phases. Their period is T = T1 + T2, and their duty cycle is T1 / T. The rising edge of signal a and the rising edge of signal b differ by half a period T / 2 in time. Signals a and b have the same period and the same duty cycle.

[0063] The dual-signal drive circuit 20 can use two half-bridge gate drivers (FAN7382) to convert the a and b signals generated by the high-frequency signal generation circuit into a1 and a2, b1 and b2 signals, and then output them. The a, a1, and a2 signals are the same, and the b, b1, and b2 signals are the same. The a1 and a2 output signals are connected to ports 1 and 4 of the inverter switch circuit, and the b1 and b2 output signals are connected to ports 2 and 3 of the inverter switch circuit.

[0064] like Figure 2 As shown, the inverter switching circuit 30 includes four MOSFETs Q1, Q2, Q3, and Q4, and four bias resistors R1, R2, R3, and R4. The gate of each MOSFET is connected to a diode and a resistor in parallel, which allows the MOSFET to turn on slowly and turn off quickly, preventing MOSFETs on the same side from turning on simultaneously. Capacitor C1 and the transmitting coil L1 in the next stage coupling coil together form an LC resonant circuit.

[0065] like Figure 3 As shown, the coupling coil 40 consists of a transmitting coil L1 and a receiving coil L2. The two ends 7 and 8 of the L1 coil are connected to the output ports 5 and 6 of the inverter switching circuit, respectively; the two ends 9 and 10 of the L2 coil are connected to the input ports 11 and 12 of the full-bridge rectifier filter circuit, respectively.

[0066] like Figure 4 As shown, the full-bridge rectifier filter circuit 50 consists of four diodes forming a full-bridge rectifier circuit. Capacitor C2 and receiving coil L2 form an LC resonant circuit; capacitor C3 is connected in parallel across the load, and its function is to filter out high-frequency noise, making the voltage applied to the load more stable; the output terminals 13 and 14 of the full-bridge rectifier filter circuit are connected to the load 60.

[0067] The working principle of the wireless power supply circuit used in oil and water wells is as follows: Two signals, a and b, are generated by a high-frequency signal generation circuit, such as... Figure 5As shown; signal a and signal b have the same period, the same duty cycle, and a phase difference of 180°. Manual resistor Rp1 is used to adjust the frequency of signals a and b, and manual resistor Rp2 is used to adjust the duty cycle of signals a and b. Signals a and b are sent as control signals to the dual-channel signal drive circuit, generating four signals a1, b1, a2, and b2. Signals a1 and a2 are identical to signal a, and signals b1 and b2 are identical to signal b. a1 is connected to the gate of Q1, b... A1 is connected to the gate of Q2, a2 ​​is connected to the gate of Q4, and b2 is connected to the gate of Q3. When signal a is high, Q1 and Q4 are simultaneously turned on, while Q2 and Q3 are turned off. Current flows through capacitor C1 and inductor L1 of Q1 to Q4. When signal b is high, Q2 and Q3 are simultaneously turned on, while Q1 and Q4 are turned off. Current flows through Q3, inductor L1, and capacitor C1 to Q2. In both cases, the current direction in inductor L1 is opposite. Every half cycle, the current direction reverses once, generating alternating current in inductor L1. The alternating current in inductor L1 is induced into inductor L2 through electromagnetic induction; the current is transmitted to the full-bridge rectifier and filter circuit; inductor L2 and capacitor C2 form a resonant circuit. When node 12 is at high voltage, diodes D6 and D7 conduct, node 13 is at high voltage, and node 14 is at low voltage; when node 11 is at high voltage, diodes D5 and D8 conduct, node 13 is still at high voltage, and node 14 is at low voltage; capacitor C3 is used to filter out noise, making the DC voltage between nodes 13 and 14 more stable; an external load resistor is connected between nodes 13 and 14.

[0068] Example 2: A debugging method for a wireless power supply circuit used in oil and water wells.

[0069] Preparation conditions: Place the coupling coil in the oil-water mixture and record the ratio of the oil-water mixture; adjust the temperature of the oil-water mixture to the temperature of the production well and record the temperature; connect the load and power supply;

[0070] 1. When the circuit is powered on, the high-frequency signal generation circuit produces two signals, a and b; for example... Figure 5 As shown;

[0071] 2. Observe signal a with an oscilloscope and manually adjust resistor Rp2 to make the duty cycle of signal a less than 50%, i.e., T1 / T<0.5;

[0072] 3. The dual-signal drive circuit generates four signals, where a1 and a2 are the same as signal a, and b1 and b2 are the same as signal b; a1, a2, b1, and b2 are connected to the input terminals 1, 4, 2, and 3 of the inverter switch circuit, and generate high-frequency AC signals at the output terminals 5 and 6 of the inverter switch circuit.

[0073] 4. Manually adjust Rp1 to generate a high-frequency signal between the output ports 5 and 6 of the inverter switch circuit, and the frequency f1 changes with Rp1; test the voltage U1, current I1 and frequency f1 across inductor L1, test the voltage U2, current I2 and frequency f2 across inductor L2, and calculate the power P1 = U1 * I1 and P2 = U2 * I2.

[0074] 5. When the ratio of P2 / P1 is at its maximum, stop adjusting Rp1, and record the resistance value of Rp1 and the frequency f1 on the L1 coil. f1 is the resonant frequency suitable for this oil-water environment.

[0075] 6. Record the current load value R1, measure the voltage U3 and current I3 across the load, and calculate the power P3 = U3 * I3; manually adjust Rp2 to make P3 reach the power value required by the load; test the waveform of signal a and calculate the duty cycle T1 / T;

[0076] 7. Record the oil-water ratio, signal a duty cycle, frequency f1; resistance values ​​Rp1 and Rp2, transmission efficiency P2 / P1, load resistance R1, and load power P3; the test is complete.

[0077] This invention uses an adjustable resistor + pulse modulation chip to generate PWM waves. The two adjustable resistors can be used to manually adjust the frequency and duty cycle of the PWM waves, making it suitable for different application environments.

[0078] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0079] Except for the technical features described in the specification, all other technologies are known to those skilled in the art.

Claims

1. A wireless power supply circuit for use in downhole oil and water wells, characterized in that, The wireless power supply circuit for oil and water wells includes a high-frequency signal generation circuit, a dual-channel signal drive circuit, an inverter switch circuit, a coupling coil, a full-bridge rectifier filter circuit, and a load. The high-frequency signal generation circuit generates a high-frequency signal and can adjust the frequency and duty cycle of the high-frequency signal. The dual-channel signal drive circuit converts the high-frequency signal generated by the high-frequency signal generation circuit into dual-channel control signals with opposite phases for driving and controlling the inverter switch circuit. Under the control of the dual-channel control signals with opposite phases, the inverter switch circuit converts DC power into high-frequency AC power. The coupling coil transmits the high-frequency AC power to the downhole oil and water space. The full-bridge rectifier filter circuit converts the high-frequency AC power received by the coupling coil into DC power and transmits it to the load.

2. The wireless power supply circuit for downhole oil and water wells according to claim 1, characterized in that, The high-frequency signal generating circuit includes a pulse width modulation chip and its peripheral circuits. The high-frequency signal generating circuit is externally connected to a first adjustable resistor and a second adjustable resistor. The frequency of the high-frequency signal generated by the pulse width modulation chip can be adjusted by manually adjusting the first adjustable resistor. The duty cycle of the high-frequency signal generated by the pulse width modulation chip can be adjusted by manually adjusting the second adjustable resistor.

3. The wireless power supply circuit for downhole oil and water wells according to claim 2, characterized in that, By adjusting the first adjustable resistor and the second adjustable resistor, the high-frequency signal generating circuit generates and outputs two high-frequency signals a and b with opposite phases, with a period of T = T1 + T2 and a duty cycle of T1 / T; and the rising edge of high-frequency signal a and the rising edge of high-frequency signal b differ in time by half a period T / 2; the periods of high-frequency signal a and high-frequency signal b are the same, and their duty cycles are also the same.

4. The wireless power supply circuit for downhole oil and water wells according to claim 3, characterized in that, The dual-channel signal drive circuit converts the a and b signals generated by the high-frequency signal generator circuit into a1 and a2, b1 and b2 signals respectively, and then outputs them; the a, a1, and a2 signals are the same, and the b, b1, and b2 signals are the same; the a1, b1, b2, and a2 signals are connected to the four input ports of the inverter switch circuit respectively.

5. The wireless power supply circuit for downhole oil and water wells according to claim 4, characterized in that, The coupling coil includes a transmitting coil and a receiving coil. The two ends of the transmitting coil are respectively connected to the two output ports of the inverter switching circuit, and the two ends of the receiving coil are respectively connected to the two input ports of the full-bridge rectifier filter circuit.

6. The wireless power supply circuit for downhole oil and water wells according to claim 5, characterized in that, The inverter switching circuit includes a first capacitor, four MOSFETs Q1, Q2, Q3, and Q4, and four bias resistors R1, R2, R3, and R4. The gate of each MOSFET is connected to a device consisting of a diode and a resistor in parallel, so that the MOSFET turns on slowly and turns off quickly, avoiding the simultaneous conduction of MOSFETs on the same side. The first capacitor and the transmitting coil in the coupling coil together form an LC resonant circuit.

7. The wireless power supply circuit for downhole oil and water wells according to claim 5, characterized in that, The full-bridge rectifier filter circuit includes a second capacitor, a third capacitor, and a full-bridge rectifier circuit composed of four diodes. The second capacitor and the receiving coil form an LC resonant circuit. The third capacitor is connected in parallel across the load to filter out high-frequency noise and make the voltage applied to the load more stable. The two output terminals of the full-bridge rectifier filter circuit are connected to the load.

8. A debugging method for a wireless power supply circuit used in oil and water wells, characterized in that, The debugging method for the wireless power supply circuit for downhole oil and water wells is used to debug the wireless power supply circuit for downhole oil and water wells as described in claim 1, comprising: Step 1: The high-frequency signal generation circuit generates two high-frequency signals a and b. The duty cycle of high-frequency signal a is adjusted by manually adjusting the second adjustable resistor. Step 2: The dual-channel signal drive circuit converts the high-frequency signals a and b into signals a1 and a2, b1 and b2, respectively, and connects them to the four input ports of the inverter switch circuit. Step 3: Manually adjust the first adjustable resistor. The output of the inverter switch circuit generates a high-frequency signal with frequency f1 varying with the first adjustable resistor. Test and calculate the power P1 of the transmitting coil and the power P2 of the receiving coil of the coupling coil. Step 4: When the ratio of P2 / P1 is at its maximum, stop adjusting the first adjustable resistor, and record the resistance value of the first adjustable resistor and the frequency f1 on the transmitting coil. f1 is the resonant frequency suitable for this oil and water environment. Step 5: Record the current load value R1, measure the voltage U3 and current I3 across the load, and calculate the load power P3 = U3 * I3; manually adjust the second adjustable resistor to make the load power P3 reach the power value required by the load; test the waveform of the high-frequency signal a and calculate the duty cycle.

9. The debugging method for a wireless power supply circuit for oil and water wells downhole according to claim 8, characterized in that, The debugging method for the wireless power supply circuit used in oil and water wells also includes, before step 1, placing the coupling coil in the oil-water mixture and recording the ratio of the oil-water mixture; adjusting the temperature of the oil-water mixture to the temperature of the production well and recording the temperature; and connecting the load and power supply.

10. The wireless power supply circuit for downhole oil and water wells and its debugging method according to claim 8, characterized in that, In step 1, the high-frequency signal generating circuit generates two high-frequency signals a and b with opposite phases. Their periods are T = T1 + T2, and their duty cycles are T1 / T. The rising edge of high-frequency signal a and the rising edge of high-frequency signal b differ in time by half a period T / 2. The periods and duty cycles of high-frequency signals a and b are the same. Observe high-frequency signal a with an oscilloscope and manually adjust the second adjustable resistor to make the duty cycle of high-frequency signal a less than 50%, i.e., T1 / T < 0.

5.

11. The wireless power supply circuit for downhole oil and water wells and its debugging method according to claim 8, characterized in that, In step 3, test the voltage U1, current I1 and frequency f1 across the transmitting coil, test the voltage U2, current I2 and frequency f2 across the receiving coil, and calculate the power P1 = U1 * I1 and P2 = U2 * I2.

12. The debugging method for a wireless power supply circuit for oil and water wells downhole according to claim 8, characterized in that, The debugging method for the wireless power supply circuit used in oil and water wells also includes, after step 5, recording the oil-water ratio, the duty cycle of the high-frequency signal a, the frequency f1; the resistance value Rp1 of the first adjustable resistor and the resistance value Rp2 of the second adjustable resistor, the transmission efficiency P2 / P1, the load resistance value R1, and the load power P3; the test is completed.

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