A downhole DC power supply and carrier communication system and a two-way communication method

Abstract

The application discloses a downhole direct current power supply and carrier communication system and a bidirectional communication method, relates to the carrier communication technical field, and aims to solve the technical problem that the existing system cannot meet the actual needs in the process of downhole oil extraction and water injection, that is, not only power supply for downhole layer measurement and control devices is needed, but also bidirectional communication with the downhole layer measurement and control devices is needed, and the system cannot meet the actual needs. The system comprises a power supply circuit unit and a power receiving circuit unit; the power supply circuit unit comprises a main controller, a power supply, a relay module and a ground signal receiving module; the power receiving circuit unit comprises measurement and control circuit units 1, 2 and 3; the measurement and control circuit units 1-3 are respectively composed of a slave controller module, a storage battery module, a carrier signal sending module, a carrier signal receiving module and a measurement and control module. The system adopts a 'one master and multiple slaves' direct current power supply and carrier communication mode, which not only improves the reliability of downhole power supply and communication, but also improves the field operation efficiency.

Description

Technical Field

[0001] This invention relates to the fields of electronic circuits and communication technology, and in particular to a downhole DC power supply and carrier communication system and communication method. Background Technology

[0002] With the rapid development of electronic information technology, power line carrier communication (PLC) has been widely used in new 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 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 to other communication methods, such as wireless communication or dedicated wired communication, DC power line carrier communication has significant advantages in wiring and maintenance costs.

[0003] In the process of cabled 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 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 the monitoring and control instruments in each downhole layer in real time, such as operating voltage, current, and battery level. Furthermore, conventional wavecode-based cableless intelligent sub-injection instruments cannot be recharged after their batteries are depleted, making them non-reusable.

[0004] Based on industry technology development trends and the aforementioned problems, this invention designs a real-time data transmission system for downhole DC power supply and bidirectional carrier communication, and designs corresponding power supply circuits, bidirectional transceiver circuits, and a half-duplex communication method suitable for transmission in downhole DC cables. This invention not only optimizes the existing cabled stratified oil production and water injection processes in oilfields, but also reduces the system's transmission error rate, laying the foundation for the intelligent upgrading and transformation of cabled stratified oil production and water injection technologies in oilfields. 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 improve the efficiency of downhole stratified monitoring and control. Furthermore, this invention helps improve oilfield production efficiency 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 includes a power supply circuit unit and a power receiving circuit unit; the power supply circuit unit mainly includes a main controller, a power supply VCC-1, a relay module RL1, and a ground signal receiving module; the power receiving circuit unit mainly includes a measurement and control circuit unit 1, a measurement and control circuit unit 2, and a measurement and control circuit unit 3, wherein the measurement and control 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 measurement and control module.

[0008] Furthermore, one end of the controlled power line of the relay module RL1 is connected to the common power line of the measurement and control circuit unit 1-3, and the other end of the controlled power line is electrically connected to the power supply VCC-1. The control terminal MCU1-TXD is connected to the signal transmitting terminal TXD of the main controller. The ground signal receiving module is connected in parallel to the two ends of the series resistor on the power supply line.

[0009] Furthermore, 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 the two ends of the transistor in the measurement and control circuit unit 1, measurement and control circuit unit 2 and measurement and control circuit unit 3, and the carrier signal receiving module is connected in parallel to the power lines in the measurement and control circuit unit 1, measurement and control circuit unit 2 and measurement and control circuit unit 3.

[0010] Furthermore, the signal transmitting terminal MCU1_TXD in the relay module RL1 is connected to the base of transistor Q1, the emitter of transistor Q1 is grounded, the collector 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; one input terminal of the relay controlled terminal is grounded, the other input terminal is connected to the power supply VCC-1, and the output terminal of the relay controlled terminal is connected to the common power line of the measurement and control circuit units 1-3.

[0011] Furthermore, the ground signal receiving module consists of an optocoupler U1, a signal receiving port MCU1-RXD, and auxiliary circuitry; the signal receiving port MCU1-RXD is connected to the signal receiving terminal RXD of the main controller; the primary side of the optocoupler U1 is connected in parallel to the two ends of the series resistor on the power supply line, and one end of the secondary side of the optocoupler U1 is connected to the power supply VDD-1 of the main controller, while the other end is connected to the signal receiving port MCU1-RXD.

[0012] Furthermore, the power line of the receiving end in the measurement and control circuit unit 1 is connected to the source of transistor Q2, and the source and gate of transistor Q2 are connected to the two ends of resistor R5 in the carrier signal transmitting module; the signal transmitting end MCU2-TXD is connected to the signal transmitting port TXD of the slave controller module MCU2, the base of transistor Q3 is connected to the signal transmitting end MCU2-TXD, and is connected to the power supply VDD-2 through a resistor, the collector of transistor Q3 is connected to the gate of transistor Q2 through resistor R6, and the emitter of transistor Q3 is grounded; the two ends of the primary side of the optocoupler U2 of the carrier signal receiving module are connected in parallel to the power line in the measurement and control circuit unit 1, one end of the secondary side of optocoupler U2 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 mainly includes temperature, pressure, and flow sensors and a servo motor.

[0013] Furthermore, the power line of the receiving end in the measurement and control circuit unit 2 is connected to the source of transistor Q4. The source and gate of transistor Q4 are connected to the two ends of resistor R10 in the carrier signal transmitting module. The signal transmitting end MCU3-TXD is connected to the signal transmitting port TXD of the slave controller module MCU3. The base of transistor Q5 is connected to the signal transmitting end MCU3-TXD and connected to the power supply VDD-3 through a resistor. The collector of transistor Q5 is connected to the gate of transistor Q4 through resistor R11. The emitter of transistor Q5 is grounded. The two ends of the primary side of the optocoupler U3 of the carrier signal receiving module are connected in parallel to the power line in the measurement and control circuit unit 2. One end of the secondary side of optocoupler U3 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 mainly includes temperature, pressure, and flow sensors and a servo motor.

[0014] Furthermore, the power line of the receiving end in the measurement and control circuit unit 3 is connected to the source of transistor Q6. The source and gate of transistor Q6 are connected to the two ends of resistor R15 in the carrier signal transmitting module. The signal transmitting end MCU4-TXD is connected to the signal transmitting port TXD of the slave controller module MCU4. The base of transistor Q7 is connected to the signal transmitting end MCU4-TXD and connected to the power supply VDD-4 through a resistor. The collector of transistor Q7 is connected to the gate of transistor Q6 through resistor R16. The emitter of transistor Q7 is grounded. The two ends of the primary side of the optocoupler U3 of the carrier signal receiving module are connected in parallel to the power line in the measurement and control circuit unit 3. One end of the secondary side of optocoupler U3 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 mainly includes temperature, pressure, and flow sensors and a servo motor.

[0015] Furthermore, the default state of the main controller's signal transmitter TXD is low, while the default state of the carrier signal transmitter module's signal transmitter is high.

[0016] Furthermore, the communication method for the downhole DC power supply and carrier communication system includes the following steps:

[0017] Step 1: When the main controller reads the measurement and control data in a certain measurement and control circuit unit, the signal transmitting terminal TXD of the main controller is set to a high level, the transistor Q1 is turned on, the relay control terminal in the relay module is connected to the current, thereby closing the controlled terminal of the relay, the common power line of the measurement and control circuit units 1-3 connected to the controlled terminal of the relay is energized, and the battery module is charged through the power line in each of the respective measurement and control circuit units.

[0018] Step 2: After the power line is energized, the main controller's signal transmitting terminal TXD sends a data packet containing "0" and "1" to the signal transmitting terminal MCU1_TXD in the relay module RL1.

[0019] Step 3: If the data "1" is sent, the signal transmitting terminal MCU1_TXD is set to high level, transistor Q1 is turned on, current flows through the relay control terminal in the relay module, the controlled terminal of the relay is closed, current flows through transistors Q2, Q4 and Q6 connected to the common power line in the measurement and control circuit unit 1-3, optocouplers U2, U3 and U4 are activated, and the signal receiving terminal of the slave controller module in the measurement and control circuit unit 1-3 receives the high level sent by the master controller;

[0020] Step 4: If the data sent is "0", the signal transmitting terminal MCU1_TXD is set to low level, transistor Q1 is turned off, the current in the relay control terminal of the relay module disappears, the relay controlled terminal is disconnected, the current in transistors Q2, Q4 and Q6 connected to the common power line in the measurement and control circuit unit 1-3 disappears, the optocouplers U2, U3 and U4 stop working, and the signal receiving terminal of the slave controller module in the measurement and control circuit unit 1-3 receives the low level sent by the master controller.

[0021] Step 5: Repeat the process of sending data "0" or "1" until all "0" and "1" in the data packet have been sent, and the signal sending end of the main controller remains at a high level.

[0022] Step 6: Parse the data packet from the controller module and analyze the address bits in the data packet to determine whether they are the same as its own address bits. If they are the same as its own address bits, the corresponding controller module sends a response signal. If they are different from its own address bits, the corresponding controller module discards the data packet, sets its own signal transmission port to a low level, and delays for half a data packet cycle. After the delay, it returns to the default state.

[0023] Step 7: When sending a response signal, a data packet containing data "0" and "1" is sent from the controller module to the signal transmission port of the connected carrier signal transmission module;

[0024] Step 8: If the data "1" is sent, the signal transmitting end in the carrier signal transmitting module is set to a high level, the transistor connected to the signal transmitting end is turned on, and current flows through the power line of the measurement and control circuit unit where the transistor is located. After being powered on, the optocoupler U1 of the ground signal receiving module connected in parallel to the power line of the power supply end works, and the signal receiving end RXD of the main controller receives the high level sent from the controller module.

[0025] Step 9: If the data to be sent is “0”, the signal transmitting end in the carrier signal transmitting module is set to a low level, the transistor connected to the signal transmitting end is turned off, and the current on the power line of the measurement and control circuit unit where the transistor is located disappears. After the current disappears, the optocoupler U1 of the ground signal receiving module connected in parallel to the power line of the power supply end stops working, and the signal receiving end RXD of the main controller receives the low level sent from the controller module.

[0026] Step 10: 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 main controller and the signal transmitting end of the carrier signal transmitting module are restored to their default states.

[0027] Step 11: The main controller parses the data packet and obtains the measurement and control data in the corresponding measurement and control circuit unit; by repeating steps 1-10, the main controller obtains the measurement and control data in any measurement and control circuit unit.

[0028] The present invention provides a downhole DC power supply and carrier communication system and a two-way communication method, which adopts a master-slave DC carrier communication circuit design. Through the downhole power line, it can not only realize the power supply of the layered measurement and control device, but also realize the two-way communication function between the ground controller and the downhole layered measurement and control device. This solves the current problems of high power supply requirements, relatively stable working voltage, and difficulty in layered measurement and control in downhole DC carrier communication. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the underground DC power supply and carrier communication system.

[0030] Figure 2 A flowchart illustrating the implementation of bidirectional communication between the downhole DC power supply and carrier communication system. Detailed Implementation

[0031] 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.

[0032] like Figure 1 The shown is a downhole DC power supply and carrier communication system, which includes a power supply circuit unit and a power receiving circuit unit.

[0033] The power supply circuit unit mainly includes the main controller MCU1, power supply VCC-1, relay module RL1, ground signal receiving module 1, resistor R3, and power supply line. Relay module RL1 mainly includes relay J1, transistor Q1, resistor R4, capacitor C2, and diode D1. The ground signal receiving module mainly includes capacitor C1, resistor R1, resistor R2, and optocoupler U1.

[0034] The power receiving circuit unit includes at least three measurement and control circuit units: unit 1, unit 2, and unit 3. These three units 1-3 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. Furthermore, unit 1 also includes at least a transistor Q2, a resistor R8, a capacitor C4, and a diode D2; unit 2 includes at least a transistor Q4, a resistor R13, a capacitor C6, and a diode D3; and unit 3 includes at least a transistor Q6, a resistor R18, a capacitor C8, and a diode D4.

[0035] The carrier signal transmitting module in the measurement and control circuit unit 1 includes resistors R5 and R6, transistor Q3 and resistor R9, and the signal transmitting terminal MCU2-TXD; the carrier signal receiving module in the measurement and control circuit unit 1 includes optocoupler U2, resistor R7, capacitor C3, and the signal receiving terminal MCU2-RXD.

[0036] The carrier signal transmitting module in the measurement and control circuit unit 2 includes resistors R10 and R11, transistor Q5 and resistor R14, as well as the signal transmitting terminal MCU3-TXD; the carrier signal receiving module in the measurement and control circuit unit 2 includes optocoupler U3, resistor R12, capacitor C5, as well as the signal receiving terminal MCU3-RXD.

[0037] The carrier signal transmitting module in the measurement and control circuit unit 3 includes resistors R15 and R16, transistor Q7 and resistor R19, and the signal transmitting terminal MCU4-TXD; the carrier signal receiving module in the measurement and control circuit unit 3 includes optocoupler U4, resistor R17, capacitor C7, and the signal receiving terminal MCU4-RXD.

[0038] The ground signal receiving module is connected in parallel across the two ends of the series resistor R3 on the power supply line; one end of the controlled power line of the relay module RL1 is connected to the common power line of the measurement and control circuit unit 1-3, and the other end of the controlled power line is electrically connected to the power supply VCC-1; the control terminal MCU1-TXD is connected to the signal transmitting terminal TXD of the main controller.

[0039] 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 the two ends of the transistor in the measurement and control circuit unit 1, measurement and control circuit unit 2 and measurement and control circuit unit 3, and the carrier signal receiving module is connected in parallel to the power lines in the measurement and control circuit unit 1, measurement and control circuit unit 2 and measurement and control circuit unit 3.

[0040] In relay module RL1, the signal transmitting terminal MCU1_TXD is connected to the base of transistor Q1, the emitter of transistor Q1 is grounded, the collector is connected to the output terminal of relay J1 control terminal, and the input terminal of relay J1 control terminal is connected to the power supply VDD-1 of main controller MCU1; one input terminal of relay J1 controlled terminal is grounded, and the other input terminal is connected to power supply VCC-1 through the power supply terminal power line, and the output terminal of relay J1 controlled terminal is connected to the common power line of measurement and control circuit units 1-3.

[0041] The ground signal receiving module consists of an optocoupler U1, a signal receiving port MCU1-RXD, and auxiliary circuitry. The signal receiving port MCU1-RXD is connected to the signal receiving terminal RXD of the main controller MCU1. The primary side of the optocoupler U1 is connected in parallel across the two ends of the series resistor R3 on the power supply line. One end of the secondary side of the optocoupler U1 is connected to the power supply VDD-1 of the main controller MCU1, and the other end is connected to the signal receiving port MCU1-RXD.

[0042] In the measurement and control circuit unit 1, the power line of the receiving end is connected to the source of transistor Q2. The source and gate of transistor Q2 are connected to the two ends of resistor R5 in the carrier signal transmitting module. The signal transmitting end MCU2-TXD is connected to the signal transmitting port TXD of the slave controller module MCU2. The base of transistor Q3 is connected to the signal transmitting end MCU2-TXD and connected to the power supply VDD-2 through a resistor. The collector of transistor Q3 is connected to the gate of transistor Q2 through resistor R6. The emitter of transistor Q3 is grounded. The two ends of the primary side of the optocoupler U2 of the carrier signal receiving module are connected in parallel to the power line in the measurement and control circuit unit 1. One end of the secondary side of optocoupler U2 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 mainly includes temperature, pressure, and flow sensors and a servo motor.

[0043] In the measurement and control circuit unit 2, the power line of the receiving end is connected to the source of transistor Q4. The source and gate of transistor Q4 are connected to the two ends of resistor R10 in the carrier signal transmitting module. The signal transmitting end MCU3-TXD is connected to the signal transmitting port TXD of the slave controller module MCU3. The base of transistor Q5 is connected to the signal transmitting end MCU3-TXD and connected to the power supply VDD-3 through a resistor. The collector of transistor Q5 is connected to the gate of transistor Q4 through resistor R11. The emitter of transistor Q5 is grounded. The two ends of the primary side of the optocoupler U3 of the carrier signal receiving module are connected in parallel to the power line in the measurement and control circuit unit 2. One end of the secondary side of optocoupler U3 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 mainly includes temperature, pressure, and flow sensors and a servo motor.

[0044] In the measurement and control circuit unit 3, the power line of the receiving end is connected to the source of transistor Q6. The source and gate of transistor Q6 are connected to the two ends of resistor R15 in the carrier signal transmitting module. The signal transmitting end MCU4-TXD is connected to the signal transmitting port TXD of the slave controller module MCU4. The base of transistor Q7 is connected to the signal transmitting end MCU4-TXD and connected to the power supply VDD-4 through a resistor. The collector of transistor Q7 is connected to the gate of transistor Q6 through resistor R16. The emitter of transistor Q7 is grounded. The two ends of the primary side of the optocoupler U3 of the carrier signal receiving module are connected in parallel to the power line in the measurement and control circuit unit 3. One end of the secondary side of optocoupler U3 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 mainly includes temperature, pressure, and flow sensors and a servo motor.

[0045] For ease of understanding, the initial state and ports of the system are described in detail below:

[0046] The default state of the signal transmitting terminal TXD 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 measurement and control circuit unit 1-3 is high level.

[0047] 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 control terminal of the relay J1 in the relay module RL1 through a resistor R4.

[0048] 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, and the input terminal of the secondary side is connected to the power supply VDD-1 of the main controller MCU1 through a series resistor R2.

[0049] Transistors Q2, Q4, and Q6 are PMOS transistors. The secondary side of optocoupler U2 is also grounded through a resistor R7 and a capacitor C3 connected in parallel. The secondary side of optocoupler U3 is also grounded through a resistor R12 and a capacitor C5 connected in parallel. The secondary side of optocoupler U4 is also grounded through a resistor R17 and a capacitor C7 connected in parallel.

[0050] The power supply VDD-1 provides power to the main controller MCU1, the control terminal of relay J1, and the secondary side of optocoupler U1.

[0051] The power supply VDD-2 provides power to the slave controller module MCU2 and the secondary side of optocoupler U2 of the measurement and control circuit unit 1;

[0052] The power supply VDD-3 provides power to the slave controller module MCU3 and the secondary side of optocoupler U3 of the measurement and control circuit unit 2;

[0053] The power supply VDD-4 provides power to the slave controller module MCU4 and the secondary side of optocoupler U4 of the measurement and control circuit unit 3;

[0054] For ease of understanding, the DC power supply and bidirectional carrier communication process of the system are described in detail below:

[0055] The system power supply process is as follows:

[0056] When the surface power supply circuit unit charges the battery module in the underground measurement and control circuit unit, its main controller MCU1 sets the corresponding signal transmitting pin TXD to a high level, turns on transistor Q1, and allows current to flow through the control terminal of relay J1 in relay module RL1, thereby closing the controlled terminal of relay J1. The common power line of measurement and control circuit units 1-3 connected to the controlled terminal of relay J1 is energized. After the common power line is energized, transistors Q2, Q4, and Q6 in measurement and control circuit units 1-3 each have current flowing through them, and charge the battery module through their respective power lines.

[0057] The system's bidirectional carrier communication method is as follows:

[0058] (1) Step 1: When the main controller MCU1 reads the measurement and control data in a certain measurement and control circuit unit, the signal transmitting terminal TXD of the main controller MCU1 is set to high level, the transistor Q1 is turned on, the control terminal of the relay J1 in the relay module RL1 is connected to current, thereby closing the controlled terminal of the relay J1, and the common power line of the measurement and control circuit units 1-3 connected to the controlled terminal of the relay J1 is energized, and the battery module Battery is charged through the power line in each of the measurement and control circuit units.

[0059] (2) Step 2: After the power line is energized, the signal transmitting terminal TXD of the main controller MCU1 sends a data packet containing “0” and “1” to the signal transmitting terminal MCU1_TXD in the relay module RL1.

[0060] (3) In step 3, if the data “1” is sent, the signal transmitting terminal MCU1_TXD is set to high level, the transistor Q1 is turned on, the control terminal of the relay J1 in the relay module RL1 is connected to current, the controlled terminal of the relay J1 is closed, the transistors Q2, Q4 and Q6 connected to the common power line in the measurement and control circuit unit 1-3 are connected to current, the optocouplers U2, U3 and U4 are working, and the signal receiving terminal RXD of the slave controller module in the measurement and control circuit unit 1-3 receives the high level sent by the master controller MCU1;

[0061] (4) Step 4: If the data sent is “0”, the signal sending terminal MCU1_TXD is set to low level, transistor Q1 is turned off, the current of the control terminal of relay J1 in relay module RL1 disappears, the controlled terminal of relay J1 is disconnected, the current of transistors Q2, Q4 and Q6 connected to the common power line in measurement and control circuit unit 1-3 disappears, the optocouplers U2, U3 and U4 stop working, and the signal receiving terminal RXD of the slave controller module in measurement and control circuit unit 1-3 receives the low level sent by the master controller MCU1;

[0062] (5) Step 5, repeat the data “0” or “1” sending process until “0” and “1” in the data packet are sent. The signal sending terminal TXD of the main controller MCU1 remains at a high level.

[0063] (6) Step 6: Parse the data packet from the controller module and analyze the address bits in the data packet to determine whether they are the same as its own address bits. If they are the same as its own address bits, the corresponding controller module sends a response signal. If they are different from its own address bits, the corresponding controller module discards the data packet, sets its own signal transmitting terminal TXD to a low level, and delays for half a data packet cycle (the time for the main controller MCU1 to acquire the measurement and control data in a certain measurement and control circuit unit is one data packet cycle). After the delay, it returns to the default state.

[0064] (7) Step 7, when sending the response signal, send a data packet containing data "0" and "1" from the controller module to the signal transmission port of the connected carrier signal transmission module;

[0065] (8) Step 8: If the data “1” is sent, the signal transmitting end in the carrier signal transmitting module is set to high level, the transistor connected to the signal transmitting end is turned on, and current flows through the power line of the measurement and control circuit unit where the transistor is located. After being powered on, the optocoupler U1 of the ground signal receiving module connected in parallel to the power line of the power supply end works, and the signal receiving end RXD of the main controller MCU1 receives the high level sent from the controller module.

[0066] (9) Step 9: If the data sent is “0”, the signal transmitting end in the carrier signal transmitting module is set to low level, the transistor connected to the signal transmitting end is turned off, and the current on the power line of the measurement and control circuit unit where the transistor is located disappears. After the current disappears, the optocoupler U1 of the ground signal receiving module connected in parallel to the power line of the power supply end stops working, and the signal receiving end RXD of the main controller MCU1 receives the low level sent from the controller module.

[0067] (10) Step 10: Repeat the data “0” or “1” transmission process until “0” and “1” in the data packet are completely transmitted; the signal transmitting end of the main controller MCU1 and the signal transmitting end of the carrier signal transmitting module are restored to the default state.

[0068] (11) Step 11: The main controller MCU1 parses the data packet and obtains the measurement and control data in the corresponding measurement and control circuit unit; by repeating steps 1-10, the main controller MCU1 obtains the measurement and control data in any measurement and control circuit unit.

Claims

1. A downhole DC 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, a power supply VCC-1, a relay module RL1 and a ground signal receiving module; the power receiving circuit unit mainly comprises a measurement and control circuit unit 1, a measurement and control circuit unit 2 and a measurement and control circuit unit 3, which are respectively composed of a slave controller module, a storage battery module, a carrier signal sending module, a carrier signal receiving module and a measurement and control module; the relay module RL1 is connected with the common power line of the measurement and control circuit units 1-3 at one end of the controlled end power line and is electrically connected with the power supply VCC-1 at the other end of the controlled end power line; the control end MCU1-TXD is connected with the signal sending end TXD of the main controller; the ground signal receiving module is connected in parallel with the two ends of the series resistor on the power supply end power line; the storage battery module is electrically connected with the slave controller module and the measurement and control module respectively, and the slave controller module is signal connected with the measurement and control module; the carrier signal sending module is connected with the two ends of the transistor in the measurement and control circuit units 1, 2 and 3, and the carrier signal receiving module is connected in parallel with the power line in the measurement and control circuit units 1, 2 and 3. The signal sending end MCU1_TXD in 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 common power line of the measurement and control circuit units 1-3.

2. A downhole DC power supply and carrier communication system according to claim 1 wherein, The ground signal receiving module is composed of a signal receiving port MCU1-RXD, an optical coupler U1 and an auxiliary circuit; the signal receiving port MCU1-RXD is connected with the signal receiving end RXD of the main controller; the primary side of the optical coupler U1 is connected in parallel with the two ends of the series resistor on the power supply end power line, one end of the secondary side of the optical coupler U1 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.

3. The downhole DC power supply and carrier communication system of claim 1, wherein, The power receiving end power line in the measurement and control circuit unit 1 is connected with the source of the transistor Q2, the source and the gate of the transistor Q2 are connected with the two ends of the resistor R5 in the carrier signal sending module; the signal sending end MCU2-TXD is connected with the signal sending port TXD of the slave controller module MCU2, the base of the transistor Q3 is connected with the signal sending end MCU2-TXD and is connected with the power supply VDD-2 through a resistor, the collector of the transistor Q3 is connected with the gate of the transistor Q2 through a resistor R6, and the emitter of the transistor Q3 is grounded; the primary side of the optical coupler U2 of the carrier signal receiving module is connected in parallel with the power line in the measurement and control circuit unit 1, one end of the secondary side of the optical coupler U2 is connected with the power supply VDD-2 of the slave controller module MCU2, the other end MCU2-RXD is connected with the signal receiving port RXD of the slave controller module MCU2; the measurement and control module mainly comprises temperature, pressure and flow sensors and a servo motor.

4. The downhole DC power supply and carrier communication system of claim 1, wherein, The power line of the power receiving end in the measurement and control circuit unit 2 is connected to the source of the transistor Q4, and the source and the gate of the transistor Q4 are connected to the resistance R10 in the carrier signal sending module; the signal sending end MCU3-TXD is connected to the signal sending port TXD of the slave controller module MCU3, the base of the transistor Q5 is connected to the signal sending end MCU3-TXD and connected to the power supply VDD-3 through a resistance, the collector of the transistor Q5 is connected to the gate of the transistor Q4 through the resistance R11, and the emitter of the transistor Q5 is grounded; the primary side of the optical coupler U3 of the carrier signal receiving module is connected in parallel to the power line in the measurement and control circuit unit 2, one end of the secondary side of the optical coupler U3 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 mainly includes temperature, pressure, flow sensors and a servo motor.

5. The downhole DC power supply and carrier communication system of claim 1, wherein, The power line of the power receiving end in the measurement and control circuit unit 3 is connected to the source of the transistor Q6, and the source and the gate of the transistor Q6 are connected to the resistance R15 in the carrier signal sending module; The signal sending end MCU4-TXD is connected to the signal sending port TXD of the slave controller module MCU4, the base of the transistor Q7 is connected to the signal sending end MCU4-TXD and connected to the power supply VDD-4 through a resistance, the collector of the transistor Q7 is connected to the gate of the transistor Q6 through the resistance R16, and the emitter of the transistor Q7 is grounded; the primary side of the optical coupler U3 of the carrier signal receiving module is connected in parallel to the power line in the measurement and control circuit unit 3, one end of the secondary side of the optical coupler U3 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 mainly includes temperature, pressure, flow sensors and a servo motor.

6. The downhole DC power supply and carrier communication system of claim 1, wherein, The default state of the signal sending end TXD of the main controller is low, and the default state of the signal sending end of the carrier signal sending module is high.

7. The downhole DC power supply and carrier communication system of claim 1, wherein, The communication method of the downhole direct current 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 measurement and control circuit unit, the signal sending end TXD of the main controller is set to high, the transistor Q1 is turned on, the relay control end in the relay module passes through the current, so that the relay controlled end is closed, the common power line of the measurement and control circuit unit 1-3 connected to the relay controlled end is powered on, and the battery module is charged through the power line in the respective measurement and control circuit unit; Step 2: after the power line is powered on, the signal sending end TXD of the main controller sends a data packet containing "0" and "1" to the signal sending end MCU1_TXD in the relay module RL1; Step 3, if the data "1" is sent, the signal sending end MCU1_TXD is set to high level, the transistor Q1 is turned on, the relay control end in the relay module has current, the relay controlled end is closed, the transistors Q2, Q4 and Q6 in the measurement and control circuit unit 1-3 connected with the public power line have current, the optocouplers U2, U3 and U4 work, the signal receiving end of the slave controller module in the measurement and control circuit unit 1-3 receives the high level sent by the master controller; Step 4, if the data "0" is sent, the signal sending end MCU1_TXD is set to low level, the transistor Q1 is turned off, the relay control end in the relay module has no current, the relay controlled end is opened, the transistors Q2, Q4 and Q6 in the measurement and control circuit unit 1-3 connected with the public power line have no current, the optocouplers U2, U3 and U4 stop working, the signal receiving end of the slave controller module in the measurement and control circuit unit 1-3 receives the low level sent by the master controller; Step 5, repeat the data "0" or "1" sending process until the data "0" and "1" in the data packet are sent, and the signal sending end of the master controller remains in the high level state; Step 6, the slave controller module parses the data packet and analyzes the address bit in the data packet to determine whether it is the same as the address bit of itself, if it is the same, the corresponding slave controller module sends a response signal, if it is not the same, the corresponding slave controller module discards the data packet, sets the signal sending end of itself to low level, and delays for half a data packet period, and then restores the default state after the delay is over; Step 7, when the response signal is sent, the slave controller module sends a data packet containing data "0" and "1" to the signal sending end of the connected carrier signal sending module; Step 8, if the data "1" is sent, the signal sending end in the carrier signal sending module is set to high level, the transistor connected with the signal sending end is turned on, and the power line of the measurement and control circuit unit where the transistor is located has current passing through, after being powered on, the optocoupler U1 of the ground signal receiving module connected in parallel with the power line of the power supply end works, and the signal receiving end RXD of the master controller receives the high level sent by the slave controller module; Step 9, if the data "0" is sent, the signal sending end in the carrier signal sending module is set to low level, the transistor connected with the signal sending end is turned off, and the power line of the measurement and control circuit unit where the transistor is located has no current, after the current disappears, the optocoupler U1 of the ground signal receiving module connected in parallel with the power line of the power supply end stops working, and the signal receiving end RXD of the master controller receives the low level sent by the slave controller module; Step 10, repeat the data "0" or "1" sending process until the data "0" and "1" in the data packet are sent, and the signal sending end of the master controller and the signal sending end of the carrier signal sending module both restore the default state; Step 11, the master controller parses the data packet and obtains the measurement and control data in the corresponding measurement and control circuit unit; by repeating steps 1-10, the master controller obtains the measurement and control data in any measurement and control circuit unit.

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