A low-voltage power supply and carrier communication system and communication method for underground wells

Abstract

This invention discloses a downhole low-voltage power supply and carrier communication system and method, relating to the field of carrier communication technology. It aims to solve the problem that during downhole oil production and water injection, the surface not only needs to supply power to the downhole monitoring and control device but also needs to communicate bidirectionally with it. Traditional cable power supply and communication systems and methods cannot meet the practical needs. The system includes a power supply circuit unit and a power receiving circuit unit. The power supply circuit unit includes a main controller, a power supply, a relay module, and a signal receiving module. The power receiving circuit unit includes circuit unit 1, circuit unit 2, and circuit unit 3, and circuit units 1-3 are respectively composed of a slave controller module, a battery module, a carrier signal transmitting module, a carrier signal receiving module, and a monitoring and control module. This system adopts a "one master, multiple slaves" DC power supply and communication mode, simplifying downhole power supply and communication equipment in oil fields, improving operational efficiency, and reducing maintenance costs.

Description

Technical Field

[0001] This invention relates to the fields of electronic circuits and communication technology, and in particular to a low-voltage power supply and carrier communication system and method for underground mining. Background Technology

[0002] With the rapid development of society and the economy, power line carrier communication (PLC) has been widely used in power systems due to its advantages such as long communication distance, low cost, and high signal transmission reliability. PLC includes AC power line carrier communication and DC power line carrier communication. In AC power line carrier communication, modulation is achieved by modulating the fundamental signal into carrier signals of different standards at the zero-crossing point of the AC signal. Demodulation is also achieved by receiving the carrier signal through the receiving circuit at the zero-crossing point and then decoding it. In DC power line carrier communication, signal attenuation is relatively small, the transmission distance is longer than that of AC power line carrier communication, and the signal on the DC power line is less susceptible to interference, especially in pure DC systems without AC fluctuations, where signal stability is high. Therefore, compared with other communication methods, such as wireless communication or dedicated wired communication, DC power line carrier communication has significant advantages in terms of wiring and maintenance costs.

[0003] In the process of wired stratified oil production and water injection in oilfields, downhole monitoring and control instruments not only require cable power supply but also need bidirectional communication with the surface to control the motor equipment in each downhole layer and collect production data (such as temperature, pressure, and flow rate). Traditional wired communication methods require fixing 1-2 communication and power lines to the outside of the lift string, which presents problems such as complex installation, high construction costs, and difficult maintenance in practical applications. In the wavecode-based cableless stratified oil production and water injection technology, the surface and downhole use wavecode for bidirectional communication, eliminating the need to fix cables to the outside of the lift string. However, this method suffers from low communication efficiency, often taking tens of minutes to complete a single communication, and it cannot monitor the working status parameters of downhole monitoring and control instruments such as operating voltage, current, and battery level in real time. Furthermore, conventional wavecode-based cableless intelligent sub-injection instruments cannot be recharged after the instrument's battery is depleted, making them non-reusable. In addition, each production well and water injection well in existing oilfields has an independent DC power line carrier communication system, resulting in serious data silos and an inability to achieve intelligent monitoring and control.

[0004] Based on industry technology development trends and the aforementioned problems, this invention designs a real-time data transmission system for downhole low-voltage power supply and DC carrier bidirectional communication, and designs corresponding bidirectional transceiver circuits and communication methods suitable for transmission in downhole DC cables. While reducing the transmission error rate, it can also realize centralized monitoring and control of multiple production wells or water injection wells by a single control cabinet on the ground, laying the foundation for the intelligent upgrading of oilfield cable-based stratified oil production and water injection technology. Summary of the Invention

[0005] Based on existing wired stratified oil production and water injection technologies in oilfields, the technical problem this invention aims to solve is to provide a new wired communication system and method for downhole stratified monitoring and control. This system can significantly reduce the bidirectional transmission error rate and break down data silos in the field, enabling centralized monitoring and control of multiple oil wells over a large area of ​​the oilfield. Furthermore, this invention helps improve the production efficiency of oilfields and provides data support for the intelligent upgrading of oilfields.

[0006] The present invention specifically adopts the following technical solutions to solve the above-mentioned technical problems:

[0007] The underground low-voltage power supply and carrier communication system is characterized in that the system mainly includes a power supply circuit unit and a power receiving circuit unit; the power supply circuit unit mainly includes a main controller MCU1, a power supply VCC-1, a relay module RL1, a relay module RL2, a relay module RL3, a signal receiving module 1, a signal receiving module 2, and a signal receiving module 3; the power receiving circuit unit mainly includes circuit unit 1, circuit unit 2, and circuit unit 3, and the three circuit units are respectively composed of a slave controller module, a battery module, a carrier signal transmitting module, a carrier signal receiving module, and a measurement and control module.

[0008] Furthermore, one end of the controlled power line of relay module RL1, relay module RL2, and relay module RL3 is connected to the power lines of circuit unit 1, circuit unit 2, and circuit unit 3, respectively, and the other end of the controlled power line is electrically connected to the power supply VCC-1; the control terminal MCU1-TXD(01) is connected to the signal transmitting terminal TXD(01) of the main controller MCU1, the control terminal MCU1-TXD(02) is connected to the signal transmitting terminal TXD(02) of the main controller MCU1, and the control terminal MCU1-TXD(03) is connected to the signal transmitting terminal TXD(03) of the main controller MCU1.

[0009] Furthermore, signal receiving modules 1, 2, and 3 are connected in parallel to the power lines connected to relay modules RL1, RL2, and RL3, respectively; the battery module is electrically connected to the slave controller module and the measurement and control module, respectively, and the slave controller module is signal-connected to the measurement and control module; the carrier signal transmitting module is connected to both ends of the transistors in circuit unit 1, circuit unit 2, and circuit unit 3, and the carrier signal receiving module is connected in parallel to the power lines in circuit unit 1, circuit unit 2, and circuit unit 3.

[0010] Furthermore, the MCU1_TXD(01) port of the relay module RL1 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the output terminal of the relay control terminal, and the input terminal of the relay control terminal is connected to the power supply VDD-1 of the main controller MCU1; one input terminal of the relay controlled terminal is grounded, and the other input terminal is connected to the power supply VCC-1 through the voltage divider resistor R3. The output terminal of the relay controlled terminal is connected to circuit unit 1, which is used to provide power to a certain downhole measurement and control equipment and realize DC carrier communication.

[0011] Furthermore, the MCU1_TXD(02) port of the relay module RL2 is connected to the base of the transistor Q3, the emitter of the transistor Q3 is grounded, the collector of the transistor Q3 is connected to the output terminal of the relay control terminal, and the input terminal of the relay control terminal is connected to the power supply VDD-1 of the main controller MCU1; one input terminal of the relay controlled terminal is grounded, and the other input terminal is connected to the power supply VCC-1 through the voltage divider resistor R12; the output terminal of the relay controlled terminal is connected to the circuit unit 2; used to provide power to another downhole measurement and control equipment and realize DC carrier communication.

[0012] Furthermore, the MCU1_TXD(03) port of the relay module RL3 is connected to the base of the transistor Q5, the emitter of the transistor Q5 is grounded, the collector of the transistor Q5 is connected to the output terminal of the relay control terminal, and the input terminal of the relay control terminal is connected to the power supply VDD-1 of the main controller MCU1; one input terminal of the relay controlled terminal is grounded, and the other input terminal is connected to the power supply VCC-1 through the voltage divider resistor R22; the output terminal of the relay controlled terminal is connected to circuit unit 3; used to provide power to other downhole measurement and control equipment and realize DC carrier communication.

[0013] Furthermore, the signal receiving module 1 consists of an optocoupler U1, a signal receiving port MCU1-RXD(01), and auxiliary circuitry; the signal receiving port MCU1-RXD(01) is connected to the signal receiving terminal RXD(01) of the main controller MCU1; the primary side of the optocoupler U1 is connected in parallel across the two ends of the voltage divider resistor R3, and is connected to the relay module RL1 and the power supply VCC-1 respectively via power lines; one end of the secondary side of the optocoupler U1 is connected to the power supply VDD-1 of the main controller via resistor R2, and the other end is connected to the signal receiving port MCU1-RXD(01).

[0014] Furthermore, the signal receiving module 2 consists of an optocoupler U4, a signal receiving port MCU1-RXD(02), and auxiliary circuitry; the signal receiving port MCU1-RXD(02) is connected to the signal receiving terminal RXD(02) of the main controller MCU1; the primary side of the optocoupler U4 is connected in parallel across the two ends of the voltage divider resistor R12, and is connected to the relay module RL2 and the power supply VCC-1 respectively via power lines; the secondary side of the optocoupler U4 is connected at one end to the power supply VDD-1 of the main controller via resistor R11, and at the other end to the signal receiving port MCU1-RXD(02).

[0015] Furthermore, the signal receiving module 3 consists of an optocoupler U7, a signal receiving port MCU1-RXD(03), and auxiliary circuitry; the signal receiving port MCU1-RXD(03) is connected to the signal receiving terminal RXD(03) of the main controller MCU1; the primary side of the optocoupler U7 is connected in parallel across the two ends of the voltage divider resistor R22, and is connected to the relay module RL3 and the power supply VCC-1 respectively via power lines; one end of the secondary side of the optocoupler U7 is connected to the power supply VDD-1 of the main controller via resistor R21, and the other end is connected to the signal receiving port MCU1-RXD(03).

[0016] Furthermore, the output terminal of the power line connected to the relay module RL1 is connected to the receiving terminal of the power line in circuit unit 1; the receiving terminal power line in circuit unit 1 is connected to the emitter of transistor Q2, and the collector of transistor Q2 is connected to the voltage divider resistor R9 through the power line; the secondary side of the optocoupler U2 in the carrier signal transmitting module is connected to the base and emitter of transistor Q2 respectively; one end of the primary side of optocoupler U2 is connected to the power supply VDD-2 of the slave controller module MCU2, and the other end MCU2-TXD is connected to the signal transmitting terminal TXD of the slave controller module MCU2; the primary side of the optocoupler U3 in the carrier signal receiving module is connected in parallel across the voltage divider resistor R9 in circuit unit 1, and the output terminal of the primary side of optocoupler U3 is connected to the battery module through the power line; one end of the secondary side of optocoupler U3 is connected to the power supply VDD-2 of the slave controller module MCU2, and the other end MCU2-RXD is connected to the signal receiving port RXD of the slave controller module MCU2; the measurement and control module includes temperature, pressure, and flow sensors, as well as servo motors, etc.

[0017] Furthermore, the output terminal of the power line connected to the relay module RL2 is connected to the receiving terminal of the power line in circuit unit 2; the receiving terminal power line in circuit unit 2 is connected to the emitter of transistor Q4, and the collector of transistor Q4 is connected to the voltage divider resistor R17 through the power line; the secondary side of the optocoupler U5 in the carrier signal transmitting module is connected to the base and emitter of transistor Q4 respectively, one end of the primary side of optocoupler U5 is connected to the power supply VDD-3 of the slave controller module MCU3, and the other end MCU3-TXD is connected to the signal transmitting terminal TXD of the slave controller module MCU3; the primary side of the optocoupler U6 in the carrier signal receiving module is connected in parallel across the voltage divider resistor R17 in circuit unit 2, and the output terminal of the primary side of optocoupler U6 is connected to the battery module through the power line; one end of the secondary side of optocoupler U6 is connected to the power supply VDD-3 of the slave controller module MCU3, and the other end MCU3-RXD is connected to the signal receiving port RXD of the slave controller module MCU3; the measurement and control module includes temperature, pressure, and flow sensors, as well as servo motors, etc.

[0018] Furthermore, the output terminal of the power line connected to the relay module RL3 is connected to the receiving terminal of the power line in circuit unit 3; the receiving terminal power line in circuit unit 3 is connected to the emitter of transistor Q6, and the collector of transistor Q6 is connected to the voltage divider resistor R27 through the power line; the secondary side of the optocoupler U8 in the carrier signal transmitting module is connected to the base and emitter of transistor Q6 respectively; one end of the primary side of optocoupler U8 is connected to the power supply VDD-4 of the slave controller module MCU4, and the other end MCU4-TXD is connected to the signal transmitting terminal TXD of the slave controller module MCU4; the primary side of the optocoupler U9 in the carrier signal receiving module is connected in parallel across the voltage divider resistor R27 in circuit unit 3, and the output terminal of the primary side of optocoupler U9 is connected to the battery module through the power line; one end of the secondary side of optocoupler U9 is connected to the power supply VDD-4 of the slave controller module MCU4, and the other end MCU4-RXD is connected to the signal receiving port RXD of the slave controller module MCU4; the measurement and control module includes temperature, pressure, and flow sensors and a servo motor.

[0019] Furthermore, the default state of the signal transmitting terminals TXD(01), TXD(02) and TXD(03) of the main controller MCU1 is low, while the default state of the signal transmitting terminal of the carrier signal transmitting module in the powered circuit unit is high.

[0020] Furthermore, the communication method for the underground low-voltage power supply and carrier communication system includes the following steps:

[0021] Step 1: When the main controller reads the measurement and control data in a certain circuit unit, the main controller sets the signal transmitting terminal connected to the corresponding circuit unit to a high level, thereby closing the controlled terminal of the connected relay module, energizing the power line in the circuit unit connected to the controlled terminal, and charging the battery module.

[0022] Step 2: After the power line is energized, the main controller sends a data packet containing "0" and "1" to the signal transmitting end. If "1" is sent, the optocoupler of the carrier signal receiving module in the circuit unit operates, and the main controller receives a high level signal from the signal receiving end of the controller module. If "0" is sent, the signal transmitting end is set to a low level, which disconnects the controlled end of the connected relay module, de-energizes the circuit unit connected to the controlled end, and thus disables the optocoupler of the carrier signal receiving module in the connected circuit unit, receiving a low level signal from the main controller from the signal receiving end of the controller module. The "0" or "1" sending process is repeated until all "0" and "1" in the data packet are sent, and the main controller's signal transmitting end remains at a high level.

[0023] Step 3: When the controller module parses the data packet and sends a response signal, it sends a data packet containing "0" and "1" to the signal port of the connected carrier signal transmitting module. If "1" is sent, the signal port of the carrier signal transmitting module is set to a high level, energizing the power line on the corresponding circuit unit. After energization, the optocoupler of the signal receiving module connected in parallel to the power line operates, and the signal receiving end of the main controller receives the high level sent by the controller module. If "0" is sent, the signal port of the carrier signal transmitting module is set to a low level, turning off the transistor on the power line connected to the carrier signal transmitting module. Consequently, no current flows through the controlled end of the relay module connected to the circuit unit, thus setting the signal receiving end of the signal receiving module connected in parallel to the power line to a low level, and the main controller receives the low level sent by the controller module. The "0" or "1" sending process is repeated until all "0" and "1" in the data packet are sent.

[0024] Step 4: The signal transmitting end of the carrier signal transmitting module and the signal transmitting end of the main controller are both restored to their default states; the main controller parses the data packets and obtains the measurement and control data in the circuit unit;

[0025] Step 5: By repeating steps 1-4, the main controller acquires measurement and control data from any circuit unit.

[0026] The underground low-voltage power supply and carrier communication system and communication method provided by this invention adopts a low-voltage DC carrier circuit design with one master and multiple slaves. It can not only realize low-voltage DC power supply through the underground power line, but also realize the communication function, thereby solving the current problem of high power supply requirements and relatively stable working voltage for underground DC carrier communication. At the same time, it realizes centralized measurement and control of multiple production wells or water injection wells by a single control cabinet on the ground. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the underground low-voltage power supply and carrier communication system.

[0028] Figure 2 A flowchart illustrating the communication implementation of the underground low-voltage power supply and carrier communication system. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings and specific implementation methods in the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] like Figure 1 The shown is a downhole low-voltage power supply and carrier communication system, which includes a power supply circuit unit and a power receiving circuit unit.

[0031] The power supply circuit unit mainly includes the main controller MCU1, power supply VCC-1, relay modules RL1, RL2, and RL3, signal receiving module 1, signal receiving module 2, and signal receiving module 3. In addition, the power supply circuit unit also includes resistors R3, R12, and R22.

[0032] The power receiving circuit unit mainly includes circuit unit 1, circuit unit 2 and circuit unit 3. The three circuit units are respectively composed of a controller module, a battery module, a carrier signal transmitting module, a carrier signal receiving module and a measurement and control module.

[0033] Relay module RL1 includes relay J1, transistor Q1, resistor R4, capacitor C2, and diode D1; relay module RL2 includes relay J2, transistor Q3, resistor R13, capacitor C6, and diode D3; relay module RL3 includes relay J3, transistor Q5, resistor R23, capacitor C10, and diode D5.

[0034] Signal receiving module 1 includes capacitor C1, resistor R1, resistor R2, and optocoupler U1; signal receiving module 2 includes capacitor C5, resistor R10, resistor R11, and optocoupler U4; signal receiving module 3 includes capacitor C9, resistor R20, resistor R21, and optocoupler U7.

[0035] The carrier signal transmitting module in circuit unit 1 includes an optocoupler U2, a resistor R5, and a resistor R6; the carrier signal receiving module in circuit unit 1 includes an optocoupler U3, a resistor R7, and a capacitor C3; in addition, circuit unit 1 also includes a transistor Q2 and a resistor R9.

[0036] The carrier signal transmitting module in circuit unit 2 includes an optocoupler U5, a resistor R14, and a resistor R15; the carrier signal receiving module in circuit unit 2 includes an optocoupler U6, a resistor R16, and a capacitor C7; in addition, circuit unit 2 also includes a transistor Q4 and a resistor R17.

[0037] The carrier signal transmitting module in circuit unit 3 includes an optocoupler U8, a resistor R24, and a resistor R25; the carrier signal receiving module in circuit unit 3 includes an optocoupler U9, a resistor R26, and a capacitor C11; in addition, circuit unit 3 also includes a transistor Q6 and a resistor R27.

[0038] One end of the controlled power line of relay module RL1, relay module RL2, and relay module RL3 is connected to the power lines of circuit unit 1, circuit unit 2, and circuit unit 3, respectively, and the other end of the controlled power line is electrically connected to the power supply VCC-1; the control terminal MCU1-TXD(01) is connected to the signal transmitting terminal TXD(01) of the main controller MCU1, the control terminal MCU1-TXD(02) is connected to the signal transmitting terminal TXD(02) of the main controller MCU1, and the control terminal MCU1-TXD(03) is connected to the signal transmitting terminal TXD(03) of the main controller MCU1.

[0039] Signal receiving modules 1, 2, and 3 are connected in parallel to the power lines connected to relay modules RL1, RL2, and RL3, respectively; the battery module is electrically connected to the slave controller module and the measurement and control module, respectively, and the slave controller module is signal-connected to the measurement and control module; the carrier signal transmitting module is connected to both ends of the transistors in circuit unit 1, circuit unit 2, and circuit unit 3, and the carrier signal receiving module is connected in parallel to the power lines in circuit unit 1, circuit unit 2, and circuit unit 3.

[0040] The MCU1_TXD(01) port of the relay module RL1 is connected to the base of transistor Q1, the emitter of transistor Q1 is grounded, the collector of transistor Q1 is connected to the output terminal of the relay control terminal, and the input terminal of the relay control terminal is connected to the power supply VDD-1 of the main controller MCU1; one input terminal of the relay controlled terminal is grounded, and the other input terminal is connected to the power supply VCC-1 through the voltage divider resistor R3. The output terminal of the relay controlled terminal is connected to circuit unit 1, which is used to provide power to a certain downhole measurement and control equipment and realize DC carrier communication.

[0041] The MCU1_TXD(02) port of relay module RL2 is connected to the base of transistor Q3, the emitter of transistor Q3 is grounded, the collector of transistor Q3 is connected to the output terminal of relay control terminal, and the input terminal of relay control terminal is connected to the power supply VDD-1 of main controller MCU1; one input terminal of relay controlled terminal is grounded, and the other input terminal is connected to power supply VCC-1 through voltage divider resistor R12, and the output terminal of relay controlled terminal is connected to circuit unit 2; used to provide power to another downhole measurement and control equipment and realize DC carrier communication.

[0042] The MCU1_TXD(03) port of relay module RL3 is connected to the base of transistor Q5, the emitter of transistor Q5 is grounded, the collector of transistor Q5 is connected to the output terminal of relay control terminal, and the input terminal of relay control terminal is connected to the power supply VDD-1 of main controller MCU1; one input terminal of relay controlled terminal is grounded, and the other input terminal is connected to power supply VCC-1 through voltage divider resistor R22, and the output terminal of relay controlled terminal is connected to circuit unit 3; used to provide power to other downhole measurement and control equipment and realize DC carrier communication.

[0043] The signal receiving module 1 consists of an optocoupler U1, a signal receiving port MCU1-RXD(01), and auxiliary circuitry. The signal receiving port MCU1-RXD(01) is connected to the signal receiving terminal RXD(01) of the main controller MCU1. The primary side of the optocoupler U1 is connected in parallel across the two ends of the voltage divider resistor R3 and is connected to the relay module RL1 and the power supply VCC-1 respectively via power lines. The secondary side of the optocoupler U1 is connected at one end to the power supply VDD-1 of the main controller via resistor R2, and at the other end to the signal receiving port MCU1-RXD(01).

[0044] The signal receiving module 2 consists of an optocoupler U4, a signal receiving port MCU1-RXD(02), and auxiliary circuits. The signal receiving port MCU1-RXD(02) is connected to the signal receiving terminal RXD(02) of the main controller MCU1. The primary side of the optocoupler U4 is connected in parallel across the two ends of the voltage divider resistor R12 and is connected to the relay module RL2 and the power supply VCC-1 respectively through the power lines. The secondary side of the optocoupler U4 is connected to the power supply VDD-1 of the main controller through the resistor R11, and the other end is connected to the signal receiving port MCU1-RXD(02).

[0045] The signal receiving module 3 consists of an optocoupler U7, a signal receiving port MCU1-RXD(03), and auxiliary circuits. The signal receiving port MCU1-RXD(03) is connected to the signal receiving terminal RXD(03) of the main controller MCU1. The primary side of the optocoupler U7 is connected in parallel across the two ends of the voltage divider resistor R22 and is connected to the relay module RL3 and the power supply VCC-1 respectively through the power lines. The secondary side of the optocoupler U7 is connected at one end to the power supply VDD-1 of the main controller through the resistor R21, and at the other end to the signal receiving port MCU1-RXD(03).

[0046] The output terminal of the power line connected to the relay module RL1 is connected to the receiving terminal of the power line in circuit unit 1; the receiving terminal power line in circuit unit 1 is connected to the emitter of transistor Q2, and the collector of transistor Q2 is connected to the voltage divider resistor R9 through the power line; the secondary side of the optocoupler U2 in the carrier signal transmitting module is connected to the base and emitter of transistor Q2 respectively; one end of the primary side of optocoupler U2 is connected to the power supply VDD-2 of the slave controller module MCU2, and the other end MCU2-TXD is connected to the signal transmitting terminal TXD of the slave controller module MCU2; the primary side of the optocoupler U3 in the carrier signal receiving module is connected in parallel across the voltage divider resistor R9 in circuit unit 1, and the output terminal of the primary side of optocoupler U3 is connected to the battery module through the power line; one end of the secondary side of optocoupler U3 is connected to the power supply VDD-2 of the slave controller module MCU2, and the other end MCU2-RXD is connected to the signal receiving port RXD of the slave controller module MCU2; the measurement and control module includes temperature, pressure, and flow sensors, as well as servo motors, etc.

[0047] The output terminal of the power line connected to relay module RL2 is connected to the receiving terminal of the power line in circuit unit 2; the receiving terminal power line in circuit unit 2 is connected to the emitter of transistor Q4, and the collector of transistor Q4 is connected to voltage divider resistor R17 through the power line; the secondary side of optocoupler U5 in carrier signal transmitting module is connected to the base and emitter of transistor Q4 respectively, one end of the primary side of optocoupler U5 is connected to the power supply VDD-3 of slave controller module MCU3, and the other end MCU3-TXD is connected to the signal transmitting terminal TXD of slave controller module MCU3; the primary side of optocoupler U6 in carrier signal receiving module is connected in parallel across voltage divider resistor R17 in circuit unit 2, and the output terminal of the primary side of optocoupler U6 is connected to battery module through power line; one end of the secondary side of optocoupler U6 is connected to the power supply VDD-3 of slave controller module MCU3, and the other end MCU3-RXD is connected to the signal receiving port RXD of slave controller module MCU3; the measurement and control module includes temperature, pressure, and flow sensors, as well as servo motors, etc.

[0048] The output terminal of the power line connected to the relay module RL3 is connected to the receiving terminal of the power line in circuit unit 3; the receiving terminal power line in circuit unit 3 is connected to the emitter of transistor Q6, and the collector of transistor Q6 is connected to the voltage divider resistor R27 through the power line; the secondary side of the optocoupler U8 in the carrier signal transmitting module is connected to the base and emitter of transistor Q6 respectively; one end of the primary side of optocoupler U8 is connected to the power supply VDD-4 of the slave controller module MCU4, and the other end MCU4-TXD is connected to the signal transmitting terminal TXD of the slave controller module MCU4; the primary side of the optocoupler U9 in the carrier signal receiving module is connected in parallel across the voltage divider resistor R27 in circuit unit 3, and the output terminal of the primary side of optocoupler U9 is connected to the battery module through the power line; one end of the secondary side of optocoupler U9 is connected to the power supply VDD-4 of the slave controller module MCU4, and the other end MCU4-RXD is connected to the signal receiving port RXD of the slave controller module MCU4; the measurement and control module includes temperature, pressure, and flow sensors and a servo motor.

[0049] For ease of understanding, the initial state and ports of the system are described in detail below:

[0050] The default state of the signal transmitting terminals TXD(01), TXD(02) and TXD(03) of the main controller MCU1 is low level, while the default state of the signal transmitting terminal of the carrier signal transmitting module in the powered circuit unit is high level.

[0051] The base of the transistor Q1 is also grounded through a diode D1 and a capacitor C2 connected in parallel, and is also connected to the input line of the relay control terminal in the relay module RL1 through a resistor R4.

[0052] The base of the transistor Q3 is also grounded through a diode D3 and a capacitor C6 connected in parallel, and is also connected to the input line of the relay control terminal in the relay module RL2 through a resistor R13.

[0053] The base of the transistor Q5 is also grounded through a diode D5 and a capacitor C10 connected in parallel, and is also connected to the input line of the relay control terminal in the relay module RL3 through a resistor R23.

[0054] The output terminal of the secondary side of the optocoupler U1 is also grounded through a resistor R1 and a capacitor C1 connected in parallel.

[0055] The output terminal of the secondary side of the optical coupler U4 is also grounded through a resistor R10 and a capacitor C5 connected in parallel.

[0056] The output terminal of the secondary side of the optical coupler U7 is also grounded through a resistor R20 and a capacitor C9 connected in parallel.

[0057] The base of transistor Q2 is also grounded through resistor R5, the base of transistor Q4 is also grounded through resistor R14, and the base of transistor Q6 is also grounded through resistor R24.

[0058] The secondary side of the optical coupler U3 is also grounded through a resistor R7 and a capacitor C3 connected in parallel.

[0059] The secondary side of the optical coupler U6 is also grounded through a resistor R16 and a capacitor C7 connected in parallel.

[0060] The secondary side of the optical coupler U9 is also grounded through a resistor R26 and a capacitor C11 connected in parallel.

[0061] Circuit unit 1 further includes capacitor C4 and diode D2; circuit unit 2 further includes capacitor C8 and diode D4; circuit unit 3 further includes capacitor C12 and diode D6.

[0062] The power supply VDD-1 provides power to the main controller MCU1, the control terminals of relays J1, J2, and J3, the secondary side of optocoupler U1, the secondary side of optocoupler U4, and the secondary side of optocoupler U7.

[0063] The power supply VDD-2 provides power to the controller module, the primary side of the optocoupler U2, and the secondary side of the optocoupler U3 of the circuit unit 1.

[0064] The power supply VDD-3 provides power to the controller module, the primary side of optocoupler U5, and the secondary side of optocoupler U6 of circuit unit 2.

[0065] The power supply VDD-4 provides power to the controller module, the primary side of the optocoupler U8, and the secondary side of the optocoupler U9 in circuit unit 3.

[0066] To facilitate understanding, the system's low-voltage power supply and carrier communication processes are described in detail below:

[0067] The system power supply process is as follows:

[0068] When the power supply circuit unit on the ground charges a certain underground battery module, its main controller MCU1 sets the corresponding signal transmitting pin to a high level. For example, when the power supply circuit unit supplies power to circuit unit 1 in the power receiving circuit unit, the signal transmitting pin TXD(01) of the main controller MCU1 is set to a high level, and the control terminal MCU1-TXD(01) connected to the TXD(01) pin is input with a high level. At this time, the emitter (E) and base (B) of transistor Q1 in relay module RL1 form a bias voltage, Q1 is turned on, the control terminal of relay J1 is energized, the contacts are closed, the controlled terminal is turned on, and the power supply VCC-1 supplies power to the power receiving circuit unit through the power line; at this time, there is a bias voltage between the emitter (E) and base (B) of transistor Q2, Q2 is turned on, and the power supply VCC-1 charges the battery module Battery through the power line.

[0069] The system's carrier communication method is as follows:

[0070] Step 1: When the main controller MCU1 reads the measurement and control data in a certain circuit unit, the main controller MCU1 sets the signal transmitting terminal connected to the corresponding circuit unit to a high level, thereby closing the controlled terminal of the connected relay module, energizing the power line in the circuit unit connected to the controlled terminal, and charging the battery module.

[0071] Step 2: After the power line is energized, the main controller MCU1 sends a data packet containing "0" and "1" to the signal transmitting end. If "1" is sent, the optocoupler of the carrier signal receiving module in the circuit unit operates, and the main controller MCU1 sends a high level signal to the signal receiving end of the controller module. If "0" is sent, the signal transmitting end is set to a low level, which disconnects the controlled end of the connected relay module, de-energizes the circuit unit connected to the controlled end, and thus disables the optocoupler of the carrier signal receiving module in the connected circuit unit, receiving a low level signal from the main controller MCU1 at the signal receiving end of the controller module. The "0" or "1" sending process is repeated until all "0" and "1" in the data packet are sent, and the signal transmitting end of the main controller MCU1 remains at a high level.

[0072] Step 3: When the controller module parses the data packet and sends a response signal, it sends a data packet containing "0" and "1" to the signal port of the connected carrier signal transmitting module. If "1" is sent, the signal port of the carrier signal transmitting module is set to a high level, energizing the power line on the corresponding circuit unit. After energization, the optocoupler of the signal receiving module connected in parallel to the power line operates, and the signal receiving end of the main controller MCU1 receives the high level sent by the controller module. If "0" is sent, the signal port of the carrier signal transmitting module is set to a low level, turning off the transistor on the power line connected to the carrier signal transmitting module. Consequently, no current flows through the controlled end of the relay module connected to the circuit unit, thus setting the signal receiving end of the signal receiving module connected in parallel to the power line to a low level, and the main controller MCU1 receives the low level sent by the controller module. The "0" or "1" sending process is repeated until all "0" and "1" in the data packet are sent.

[0073] Step 4: The signal transmitting end of the carrier signal transmitting module and the signal transmitting end of the main controller MCU1 are both restored to their default states; the main controller MCU1 parses the data packets and obtains the measurement and control data in the circuit unit;

[0074] Step 5: By repeating steps 1-4, the main controller MCU1 acquires measurement and control data from any circuit unit.

[0075] like Figure 2 The flowchart shown illustrates the communication implementation of the downhole low-voltage power supply and carrier communication system. This embodiment uses the example of the main controller MCU1 reading measurement and control data from circuit unit 1 to describe the communication implementation process in detail:

[0076] (1) The system starts the power supply process of circuit unit 1, and the battery in circuit unit 1 is charged.

[0077] (2) After the power line is energized, the main controller MCU1 sends a data packet containing “0” and “1” to the signal transmitting terminal TXD(01);

[0078] (3) If the data "1" is sent, the signal transmitting pin TXD(01) is set to a high level, and the MCU1_TXD(01) port of the relay module RL1 connected to TXD(01) is set to a high level. The emitter (E) and base (B) of transistor Q1 form a bias voltage, and the emitter (E) and collector (C) of transistor Q1 are connected. After the control terminal of relay J1 is energized, the controlled terminal is closed, and the power supply VCC-1 supplies power to the receiving circuit unit through the power line. At this time, the optocoupler When the voltages across the primary side of U2 are equal, the secondary side of optocoupler U2 is not conducting. A bias voltage exists between the emitter (E) and base (B) of transistor Q2, and the emitter (E) and collector (C) of transistor Q2 are conducting. At this time, a voltage difference appears across the primary side of optocoupler U3, so the secondary side of optocoupler U3 is conducting. The MCU2-RXD port connected to the secondary side of optocoupler U3 receives a high-level signal and receives the high-level signal sent by the main controller, i.e., data "1", from the signal receiving terminal RXD of the controller module MCU2.

[0079] (4) If the data “0” is sent, the signal transmitting terminal TXD(01) pin is set to low level, and the MCU1_TXD(01) port of the relay module RL1 connected to TXD(01) is set to low level. The bias voltage of the emitter (E) and base (B) of the transistor Q1 disappears, and the emitter (E) and collector (C) terminals of Q1 are not connected. After the control terminal of the relay J1 is de-energized, the controlled terminal is disconnected, and the power receiving circuit unit connected to the controlled terminal of the relay J1 stops supplying power. At this time, the voltage difference between the primary side and the secondary side of the optocoupler U3 disappears, and the secondary side of the optocoupler U3 is not connected. The MCU2-RXD port connected to the secondary side of the optocoupler U3 receives a low-level signal and receives the low level sent by the main controller, i.e., the data “0”, from the signal receiving terminal RXD of the controller module MCU2.

[0080] (5) Repeat the process of sending data “0” or “1” until all “0” and “1” in the data packet are sent. The signal sending terminal TXD(01) of the main controller MCU1 remains at a high level.

[0081] (6) When parsing the data packet and sending the response signal from the controller module MCU2, a data packet containing “0” and “1” is sent from the signal transmitting terminal TXD of the controller module MCU2 to the signal port MCU2-TXD of the connected carrier signal transmitting module;

[0082] (7) If the data “1” is sent, the signal port MCU2-TXD of the carrier signal transmitting module is set to high level, there is no voltage difference on the primary side of the optocoupler U2, the secondary side of the optocoupler U2 is not conducting, the emitter (E) and base (B) of the transistor Q2 have bias voltage, the emitter (E) and collector (C) of the transistor Q2 are conducting, so that the power line on the corresponding circuit unit 1 is energized; after being energized, a voltage difference appears on the primary side of the optocoupler U1 of the signal receiving module 1 connected in parallel to the power line, the secondary side of the optocoupler U1 is conducting, the MCU1-RXD(01) port connected to the secondary side of the optocoupler U1 receives a high level signal, and the signal receiving terminal RXD(01) of the main controller MCU1 receives a high level sent from the controller module MCU2, that is, the data “1”.

[0083] (8) If the data “0” is sent, the signal port MCU2-TXD of the carrier signal sending module is set to low level, and a voltage difference is formed on the primary side of the optocoupler U2. At this time, the secondary side of the optocoupler U2 is turned on, the bias voltage of the emitter (E) and base (B) of the transistor Q2 disappears, and the emitter (E) and collector (C) of the transistor Q2 are not turned on. As a result, no current flows through the controlled terminal of the relay module RL1 connected to the circuit unit 1, so that the voltage difference of the primary side of the optocoupler U1 in the signal receiving module 1 connected in parallel with the power line disappears. At this time, the secondary side of the optocoupler U1 is not turned on, and the MCU1-RXD(01) port connected to the secondary side of the optocoupler U1 receives a low level signal. The signal receiving terminal RXD(01) of the main controller MCU1 receives the low level sent from the controller module MCU2. The main controller receives the low level sent from the controller, that is, the data “0”.

[0084] (9) Repeat the data "0" or "1" transmission process until all "0" and "1" in the data packet have been transmitted. The signal transmitting end of the carrier signal transmitting module in circuit unit 1 returns to the default state, and the signal transmitting end TXD(01) of the main controller MCU1 returns to the default state. The main controller MCU1 parses the data packet and obtains the measurement and control data in the circuit unit 1.

[0085] (10) By repeating the above (1)-(9) process, the main controller MCU1 can acquire the measurement and control data in any circuit unit.

Claims

1. A downhole low voltage power supply and carrier communication system, characterized by, The system comprises a power supply circuit unit and a power receiving circuit unit; the power supply circuit unit mainly comprises a main controller MCU1, a power supply VCC-1, relay modules RL1, RL2 and RL3, signal receiving modules 1, 2 and 3; the power receiving circuit unit mainly comprises circuit units 1, 2 and 3, which are respectively composed of a slave controller module, a battery module, a carrier signal sending module, a carrier signal receiving module and a measurement and control module; one end of the controlled end power lines of the relay modules RL1, RL2 and RL3 is respectively connected with the power lines of the circuit units 1, 2 and 3, and the other end of the controlled end power lines is electrically connected with the power supply VCC-1; the control end MCU1-TXD(01) is connected with the signal sending end TXD(01) of the main controller MCU1, the control end MCU1-TXD(02) is connected with the signal sending end TXD(02) of the main controller MCU1, and the control end MCU1-TXD(03) is connected with the signal sending end TXD(03) of the main controller MCU1; the signal receiving modules 1, 2 and 3 are respectively connected in parallel with the power lines connected with the relay modules RL1, RL2 and RL3; the battery module is electrically connected with the slave controller module and the measurement and control module, and the slave controller module is signal connected with the measurement and control module; the carrier signal sending module is connected between the two ends of the transistor in the circuit units 1, 2 and 3, and the carrier signal receiving module is connected in parallel with the power lines in the circuit units 1, 2 and 3; The MCU1_TXD(01) port of the relay module RL1 is connected with the base of the transistor Q1, the emitter of the transistor Q1 is grounded, the collector is connected with the outgoing end of the relay control end, the incoming end of the relay control end is connected with the power supply VDD-1 of the main controller, one incoming end of the controlled end of the relay is grounded, the other incoming end is connected with the power supply VCC-1, and the outgoing end of the controlled end of the relay is connected with the circuit unit 1; the MCU1_TXD(02) port of the relay module RL2 is connected with the base of the transistor Q3, the emitter of the transistor Q3 is grounded, the collector is connected with the outgoing end of the relay control end, the incoming end of the relay control end is connected with the power supply VDD-1 of the main controller, one incoming end of the controlled end of the relay is grounded, the other incoming end is connected with the power supply VCC-1, and the outgoing end of the controlled end of the relay is connected with the circuit unit 2; the MCU1_TXD(03) port of the relay module RL3 is connected with the base of the transistor Q5, the emitter of the transistor Q5 is grounded, the collector is connected with the outgoing end of the relay control end, the incoming end of the relay control end is connected with the power supply VDD-1 of the main controller, one incoming end of the controlled end of the relay is grounded, the other incoming end is connected with the power supply VCC-1, and the outgoing end of the controlled end of the relay is connected with the circuit unit 3.

2. The downhole low-voltage power supply and carrier communication system of claim 1, wherein, The signal receiving module 1 is composed of an optical coupler U1, a signal receiving port MCU1-RXD(01) and an auxiliary circuit; the signal receiving port MCU1-RXD(01) is connected with a signal receiving end RXD(01) of the main controller MCU1; the primary side of the optical coupler U1 is connected in parallel with a power line connected with the relay module RL1, one end of the secondary side of the optical coupler U1 is connected with a power supply VDD-1 of the main controller, and the other end is connected with the signal receiving port MCU1-RXD(01); the signal receiving module 2 is composed of an optical coupler U4, a signal receiving port MCU1-RXD(02) and an auxiliary circuit; the signal receiving port MCU1-RXD(02) is connected with a signal receiving end RXD(02) of the main controller MCU1; the primary side of the optical coupler U4 is connected in parallel with a power line connected with the relay module RL2, one end of the secondary side of the optical coupler U4 is connected with the power supply VDD-1 of the main controller, and the other end is connected with the signal receiving port MCU1-RXD(02); the signal receiving module 3 is composed of an optical coupler U7, a signal receiving port MCU1-RXD(03) and an auxiliary circuit; the signal receiving port MCU1-RXD(03) is connected with a signal receiving end RXD(03) of the main controller MCU1; the primary side of the optical coupler U7 is connected in parallel with a power line connected with the relay module RL3, one end of the secondary side of the optical coupler U7 is connected with the power supply VDD-1 of the main controller, and the other end is connected with the signal receiving port MCU1-RXD(03).

3. The downhole low-voltage power supply and carrier communication system of claim 1, wherein, The power receiving end power line in the circuit unit 1 is connected with an emitter of a triode Q2, the secondary side of the optical coupler U2 of the carrier signal sending module is connected with the base and the emitter of the triode Q2 respectively, one end of the primary side of the optical coupler U2 is connected with the power supply VDD-2 of the slave controller module MCU2, and the other end MCU2-TXD is connected with the signal sending end TXD of the slave controller module MCU2; the primary side of the optical coupler U3 of the carrier signal receiving module is connected in parallel with the power line in the circuit unit 1, one end of the secondary side of the optical coupler U3 is connected with the power supply VDD-2 of the slave controller module MCU2, and the other end MCU2-RXD is connected with the signal receiving end RXD of the slave controller module MCU2; the measurement and control module includes temperature, pressure and flow sensors and a servo motor.

4. The downhole low-voltage power supply and carrier communication system of claim 1, wherein, The power receiving end power line in the circuit unit 2 is connected with an emitter of a triode Q4, the secondary side of the optical coupler U5 of the carrier signal sending module is connected with the base and the emitter of the triode Q4 respectively, one end of the primary side of the optical coupler U5 is connected with the power supply VDD-3 of the slave controller module MCU3, and the other end MCU3-TXD is connected with the signal sending end TXD of the slave controller module MCU3; the primary side of the optical coupler U6 of the carrier signal receiving module is connected in parallel with the power line in the circuit unit 2, one end of the secondary side of the optical coupler U6 is connected with the power supply VDD-3 of the slave controller module MCU3, and the other end MCU3-RXD is connected with the signal receiving end RXD of the slave controller module MCU3; the measurement and control module includes temperature, pressure and flow sensors and a servo motor.

5. The downhole low-voltage power supply and carrier communication system of claim 1, wherein, The power line in the circuit unit 3 is connected with the emitter of the triode Q6, the light coupler U8 of the carrier signal sending module is connected with the base and the emitter of the triode Q6 respectively, one end of the light coupler U8 is connected with the power supply VDD-4 of the slave controller module MCU4, and the other end MCU4-TXD is connected with the signal sending end TXD of the slave controller module MCU4; the light coupler U9 of the carrier signal receiving module is connected with the power line in the circuit unit 3 in parallel, one end of the light coupler U9 is connected with the power supply VDD-4 of the slave controller module MCU4, and the other end MCU4-RXD is connected with the signal receiving port RXD of the slave controller module MCU4; the measurement and control module comprises temperature, pressure and flow sensors and a servo motor.

6. The downhole low-voltage power supply and carrier communication system of claim 1, wherein, The default state of the signal sending ends TXD(01), TXD(02) and TXD(03) of the main controller MCU1 is low level, and the default state of the signal sending end of the carrier signal sending module is high level.

7. The downhole low-voltage power supply and carrier communication system of claim 1, wherein, The communication method of the downhole low-voltage power supply and carrier communication system comprises the following steps: Step 1, when the main controller reads the measurement and control data in a certain circuit unit, the main controller sets the signal sending end connected with the corresponding circuit unit to high level, so that the controlled end of the connected relay module is closed, the power line in the circuit unit connected with the controlled end is powered on and the battery module is charged; Step 2, after the power line is powered on, the main controller sends a data packet containing "0" and "1" to the signal sending end; if "1" is sent, the light coupler of the carrier signal receiving module in the circuit unit works, and the signal receiving end of the slave controller module receives the high level sent by the main controller; if "0" is sent, the signal sending end is set to low level, the controlled end of the connected relay module is disconnected, the circuit unit connected with the controlled end is powered off, and then the light coupler of the carrier signal receiving module in the connected circuit unit does not work, and the signal receiving end of the slave controller module receives the low level sent by the main controller; the "0" or "1" sending process is repeated until the "0" and "1" in the data packet are sent completely, and the signal sending end of the main controller remains in high level state; Step 3, when the slave controller module analyzes the data packet and sends a response signal, the slave controller module sends a data packet containing "0" and "1" to the signal port of the connected carrier signal sending module; if "1" is sent, the signal port of the carrier signal sending module is set to high level, the power line on the corresponding circuit unit is powered on, the light coupler of the signal receiving module connected in parallel with the power line works after being powered on, and the signal receiving end of the main controller receives the high level sent by the slave controller module; if "0" is sent, the signal port of the carrier signal sending module is set to low level, the triode connected with the carrier signal sending module on the power line is turned off, and then the controlled end of the relay module connected with the circuit unit has no current flowing through, so that the signal receiving end of the signal receiving module connected in parallel with the power line is set to low level, and the main controller receives the low level sent by the slave controller module; The "0" or "1" sending process is repeated until the "0" and "1" in the data packet are sent completely; In step 4, the signal sending end of the carrier signal sending module and the signal sending end of the main controller are restored to the default state; and the main controller parses the data packet to obtain the measurement and control data in the circuit unit; In step 5, the main controller obtains the measurement and control data in any circuit unit by repeating steps 1-4.

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