Underground direct current power supply and carrier communication circuit

Abstract

The utility model discloses an underground direct-current power supply and carrier communication circuit, relates to the technical field of carrier communication, and aims to overcome the strict conditions that the existing underground direct-current carrier communication has high requirements on the quality of a power supply and the voltage needs to be relatively stable, and solve the technical problem that the error rate of transmission signals is large due to voltage fluctuation when a measurement and control device is started and stopped. The circuit comprises a power supply circuit unit and a power receiving circuit unit, wherein the power supply circuit unit comprises a main controller MCU1, a ground carrier signal transmitting module, a ground carrier signal receiving module, an MOS tube Q2, a power supply VCC-1 and the like; the power receiving circuit unit comprises a slave controller MCU2, a downhole carrier signal sending module, a downhole carrier signal receiving module, an MOS tube Q3, a storage battery module, a measurement and control unit module and the like. The DC power supply and carrier communication circuit designed by the utility model not only can realize power supply, but also can realize bidirectional communication.

Description

Technical Field

[0001] This invention relates to the fields of electronic circuits and communication technology, and in particular to a DC power supply and carrier communication circuit for underground wells. Background Technology

[0002] When the master and slave devices communicate with each other, in terms of hardware, any form of communication cannot do without two major channels: power supply and signal. Conventional communication methods mostly use a method where power supply and communication are independent. This communication method requires four transmission lines as carriers to complete the power supply and communication functions, which is complex in structure and inconvenient in wiring. In many situations, there are no such conditions for use. Even if such conditions exist, the communication lines are complex and costly, which will also lead to waste of resources and affect efficiency.

[0003] Currently, most DC carrier circuits work by raising the logic 0 and logic 1 levels, ensuring that the power supply line still has a certain voltage when transmitting logic 0, thus supplying power to the receiving end. However, the aforementioned DC carrier circuits, which rely heavily on raising the logic 0 and logic 1 levels to supply power to the receiving end, have high power supply requirements and require relatively stable voltage, leading to significant errors when voltage fluctuations occur.

[0004] Based on technological development trends and the aforementioned problems, this utility model designs a downhole DC power supply and carrier communication circuit. This circuit can not only reduce the transmission error rate of downhole measurement and control data, but also realize centralized measurement and control of production well stratified oil production or stratified water injection by a single ground control cabinet, laying the foundation for the intelligent upgrading of oilfield cabled stratified oil production and water injection technology. Summary of the Invention

[0005] The DC power supply and carrier communication circuit provided by this utility model can overcome the strict requirements of high power quality and relatively stable voltage in the current DC carrier communication system for underground wells, and solve the technical problem of high bit error rate of transmission signal caused by voltage fluctuation when the monitoring and control device starts and stops.

[0006] This embodiment provides a downhole DC power supply and carrier communication circuit, including a power supply circuit unit and a power receiving circuit unit. The power supply circuit unit includes at least a main controller MCU1, a ground carrier signal transmitting module, a ground carrier signal receiving module, a MOSFET Q2, a resistor R5, and a power supply VCC-1. The power receiving circuit unit includes at least a slave controller MCU2, a downhole ground carrier signal transmitting module, a downhole ground carrier signal receiving module, a MOSFET Q3, a resistor R12, a battery module, and a measurement and control unit module.

[0007] Furthermore, the input port MCU1-TXD of the ground carrier signal transmission module is connected to the TXD port of MCU1, the power supply port VDD-1 is connected to the power supply VDD-1 of MCU1, and the ground carrier signal transmission module is connected to the gate and source of MOSFET Q2; the drain of MOSFET Q2 is connected to the ground carrier signal receiving module, and the source of MOSFET Q2 is connected to the power supply VCC-1; the ground carrier signal receiving module is connected in parallel across the two ends of the series resistor R5 on the power supply side, the power supply port VDD-1 is connected to the power supply VDD-1 of MCU1, and the output port MCU1-RXD of the ground carrier signal receiving module is connected to the RXD port of MCU1;

[0008] Furthermore, the output terminal of the power supply circuit unit is connected to the input terminal of the power receiving circuit unit via a power line, and the input terminal of the power receiving circuit unit is connected to the source of the MOSFET Q3.

[0009] Furthermore, the downhole ripple signal transmitting module is connected to the gate and source of MOSFET Q3, and its power supply port VDD-2 is connected to the power supply VDD-2 of MCU2. The input port MCU2-TXD of the downhole ripple signal transmitting module is connected to the TXD port of MCU2. The downhole ripple signal receiving module is connected in parallel across the series resistor R12 on the power line on the receiving side. Its power supply port VDD-2 is connected to the power supply VDD-2 of MCU2, and its output port MCU2-RXD is connected to the RXD port of MCU2. The battery module is electrically connected to resistor R12, the measurement and control unit module, and MCU2. MCU2 is signal-connected to the measurement and control unit module.

[0010] Furthermore, the ground carrier signal transmission module includes at least a transistor Q1, resistors R1, R2, and R3, a capacitor C1, and a diode D1; the emitter of Q1 is grounded, and the collector of Q1 is connected to the gate of the MOSFET Q2 through resistor R1; the base of Q1 is connected to the input port MCU1-TXD and to the power supply VDD-1 through resistor R2; one end of capacitor C1 is grounded, and the other end is connected to the base of Q1; one end of diode D1 is grounded, and the other end is connected to the base of Q1.

[0011] Furthermore, the ground carrier signal receiving module includes at least an optical coupler U1, a resistor R4, a resistor R6, and a capacitor C2; one end of the secondary side of the optical coupler U1 is connected to the power port VDD-1 through the resistor R4, and the other end is connected to the output port MCU1-RXD; one end of the resistor R6 and the capacitor C2 are grounded, and the other end is connected to the output port MCU1-RXD.

[0012] Furthermore, the well-grounded wave signal transmission module includes at least transistor Q4, resistors R7, R8, and R9; the collector of Q4 is connected to the gate of Q3 through the series resistor R8, and to the source of Q3 through the series resistors R8 and R7; the emitter of Q4 is grounded; the base of Q4 is connected to the input port MCU2-TXD, and to the power supply port VDD-2 through resistor R9;

[0013] Furthermore, the well-ground radio wave signal receiving module includes at least an optocoupler U2, resistors R10 and R11, capacitor C3, and resistor C4; the primary side of the optocoupler U2 is connected to the drain of the MOSFET Q3, one end of the secondary side of the optocoupler U2 is connected to the power supply VDD-2, and the other end is connected to the output port MCU2-RXD through resistor R11; one end of resistor R10 and capacitor C3 is grounded, and the other end is connected to the secondary side of the optocoupler U2; one end of resistor C4 is grounded, and the other end is connected to the output port MCU2-RXD.

[0014] Furthermore, the power receiving circuit unit also includes a resistor C5 and a diode D2; one end of the resistor C5 and the diode D2 is grounded, and the other end is connected to the battery module. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a circuit structure for a downhole DC power supply and carrier communication circuit. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific implementation methods. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0018] like Figure 1 The diagram shows a downhole DC power supply and carrier communication circuit, the circuit including a power supply circuit unit and a power receiving circuit unit;

[0019] The power supply circuit unit includes at least a main controller MCU1, a ground carrier signal transmitting module, a ground carrier signal receiving module, a power supply VCC-1, a MOSFET Q2, and a resistor R5; the power receiving circuit unit includes at least a slave controller MCU2, a ground carrier signal transmitting module, a ground carrier signal receiving module, a MOSFET Q3, a resistor R12, a battery module, and a measurement and control unit module; the input port MCU1-TXD of the ground carrier signal transmitting module is connected to the TXD port of MCU1, the power supply port VDD-1 is connected to the power supply VDD-1 of MCU1, and the ground carrier signal transmitting module is connected to the gate and source of MOSFET Q2; the drain of MOSFET Q2 is connected to the ground carrier signal receiving module, and the source of MOSFET Q2 is connected to the power supply VCC-1; the ground carrier signal receiving module is connected in parallel across the two ends of the series resistor R5 on the power supply side line, the power supply port VDD-1 is connected to the power supply VDD-1 of MCU1, and the output port MCU1-RXD of the ground carrier signal receiving module is connected to the RXD port of MCU1;

[0020] The output terminal of the power supply circuit unit is connected to the input terminal of the power receiving circuit unit via a power line, and the input terminal of the power receiving circuit unit is connected to the source of the MOSFET Q3.

[0021] The downhole waveform signal transmitting module is connected to the gate and source of MOSFET Q3, and its power supply port VDD-2 is connected to the power supply VDD-2 of MCU2. The input port MCU2-TXD of the downhole waveform signal transmitting module is connected to the TXD port of MCU2. The downhole waveform signal receiving module is connected in parallel across the series resistor R12 on the power line on the receiving side. Its power supply port VDD-2 is connected to the power supply VDD-2 of MCU2, and its output port MCU2-RXD is connected to the RXD port of MCU2. The battery module is electrically connected to resistor R12, the measurement and control unit module, and MCU2. MCU2 is signal-connected to the measurement and control unit module.

[0022] The ground carrier signal transmission module includes at least transistor Q1, resistors R1, R2, and R3, capacitor C1, and diode D1. The emitter of Q1 is grounded, and the collector of Q1 is connected to the gate of MOSFET Q2 through resistor R1. The base of Q1 is connected to the input port MCU1-TXD and to the power supply VDD-1 through resistor R2. One end of capacitor C1 is grounded, and the other end is connected to the base of Q1. One end of diode D1 is grounded, and the other end is connected to the base of Q1.

[0023] The ground carrier signal receiving module includes at least an optocoupler U1, a resistor R4, a resistor R6, and a capacitor C2; one end of the secondary side of the optocoupler U1 is connected to the power port VDD-1 through the resistor R4, and the other end is connected to the output port MCU1-RXD; one end of the resistor R6 and the capacitor C2 are grounded, and the other end is connected to the output port MCU1-RXD.

[0024] The well-download waveform signal transmission module includes at least transistor Q4, resistor R7, resistor R8, and resistor R9; the collector of Q4 is connected to the gate of Q3 through the series resistor R8, and is connected to the source of Q3 through the series resistors R8 and R7; the emitter of Q4 is grounded; the base of Q4 is connected to the input port MCU2-TXD, and is connected to the power supply port VDD-2 through resistor R9;

[0025] The well-ground radio wave signal receiving module includes at least an optocoupler U2, resistor R10, resistor R11, capacitor C3, and resistor C4. The primary side of optocoupler U2 is connected to the drain of MOSFET Q3. One end of the secondary side of optocoupler U2 is connected to power supply VDD-2, and the other end is connected to the output port MCU2-RXD through resistor R11. One end of resistor R10 and capacitor C3 is grounded, and the other end is connected to the secondary side of optocoupler U2. One end of resistor C4 is grounded, and the other end is connected to the output port MCU2-RXD.

[0026] The power receiving circuit unit also includes a resistor C5 and a diode D2; one end of the resistor C5 and the diode D2 is grounded, and the other end is connected to the battery module.

[0027] The measurement and control unit module includes temperature sensors, pressure sensors, flow sensors, and drive motors, etc.

[0028] Power supply principle:

[0029] Based on the characteristics of the designed circuit, the default state of input port MCU1-TXD is low, and the default state of input port MCU2-TXD is high. When MCU1 in the power supply circuit unit starts power supply or communication, its MCU1-TXD pin outputs a high level, and the emitter (E) and collector (C) terminals of transistor Q1 are turned on, thereby turning on the source and drain terminals of MOSFET Q2 on the power supply side line. The power supply VCC-1 supplies power to the receiving circuit unit through MOSFET Q2 and resistor R5 on the power supply side line. At this time, the source and drain terminals of MOSFET Q3 are turned on, and electrical energy supplies power to the battery and measurement and control unit module through MOSFET Q3 and resistor R12 on the receiving side line.

[0030] The power supply circuit unit sends data:

[0031] When the TXD port of the main controller MCU1 in the power supply circuit unit sends a high-level signal (i.e., data "1") to the input port MCU1-TXD, a bias voltage is formed between the base and emitter of transistor Q1, and the emitter and collector of transistor Q1 are turned on. After transistor Q1 is turned on, a bias voltage is formed between the gate and source of MOSFET Q2, and the source and drain of MOSFET Q2 are turned on. The power supply voltage VCC-1 supplies power to the power receiving circuit unit through the power supply side power line, MOSFET Q2, and resistor R5. The input port MCU2-TXD in the low-voltage signal transmission module... XD is in a high-level state by default. A bias voltage is formed between the base and emitter of transistor Q4, and the collector and emitter of transistor Q4 remain in a conducting state. When a voltage appears on the power line on the receiving side, a bias voltage appears between the gate and source of MOSFET Q3, and the source and drain of MOSFET Q3 are turned on. At this time, there is a voltage across resistor R12 on the power line on the receiving side, and the optocoupler U2 in the downwave signal receiving module works. The output port MCU2-RXD outputs a high level, and the high level output from the output port MCU2-RXD is received from the RXD port of controller MCU2.

[0032] When the TXD port of the main controller MCU1 in the power supply circuit unit sends a low-level signal (i.e., data "0") to the input port MCU1-TXD, there is no bias voltage between the base and emitter of transistor Q1, and the emitter and collector of transistor Q1 are not conducting. After transistor Q1 is turned off, there is no bias voltage between the gate and source of MOSFET Q2, and the source and drain of MOSFET Q2 are not conducting. At this time, there is no voltage on the power line in the power receiving circuit unit connected to the power supply side power line; the optocoupler U2 in the low-level ripple signal receiving module in the power receiving circuit unit does not work, the output port MCU2-RXD outputs a low level, and the low level output by the output port MCU2-RXD is received from the RXD port of controller MCU2.

[0033] After the power supply circuit unit finishes sending data, the input port MCU1-TXD remains at a high level.

[0034] The receiving circuit unit transmits data:

[0035] The power receiving circuit unit parses the data sent by the main controller MCU1 from the controller MCU2 and obtains the corresponding measurement and control data from the downhole measurement and control unit module.

[0036] When a high-level signal (i.e., data "1") is sent from the TXD port of the controller MCU2 to the input port MCU2-TXD, the base voltage of transistor Q4 increases, and the collector and emitter of transistor Q4 are turned on. At this time, a bias voltage appears between the gate and source of MOSFET Q3, and current flows through the source and drain of MOSFET Q3. A voltage exists across resistor R5 on the power supply line connected to the power receiving side. The optocoupler U1 in the ground carrier signal receiving module is activated, and the output port MCU1-RXD outputs a high level. The RXD port of the main controller MCU1 receives the high level output from the output port MCU1-RXD.

[0037] When a low-level signal (i.e., data "0") is sent from the TXD port of the controller MCU2 to the input port MCU2-TXD, the base voltage of transistor Q4 decreases, the bias voltage between the base and emitter of transistor Q4 disappears, the collector and emitter of transistor Q4 are not conducting, the bias voltage between the gate and source of MOSFET Q3 disappears, the source and drain of MOSFET Q3 are turned off, there is no voltage difference across resistor R5 on the power supply line connected to the power receiving side, the optocoupler U1 in the ground carrier signal receiving module does not work, the output port MCU1-RXD outputs a low level, and the RXD port of the main controller MCU1 receives the low level output by the output port MCU1-RXD.

[0038] The main controller MCU1 can obtain the measurement and control data of the equipment in the downhole measurement and control unit module by parsing the data sent from the controller MCU2.

Claims

1. A downhole DC power supply and carrier communication circuit, characterized in that, The circuit includes a power supply circuit unit and a power receiving circuit unit. The power supply circuit unit includes at least a main controller MCU1, a ground carrier signal transmitting module, a ground carrier signal receiving module, a MOSFET Q2, a resistor R5, and a power supply VCC-1. The power receiving circuit unit includes at least a slave controller MCU2, a ground carrier signal transmitting module, a MOSFET Q3, a resistor R12, a ground carrier signal receiving module, a battery module, and a measurement and control unit module. The input port MCU1-TXD of the ground carrier signal transmitting module is connected to the TXD port of MCU1, and the power supply port VDD-1 is connected to the power supply VDD-1 of MCU1. The ground carrier signal transmitting module is connected to the gate and source of MOSFET Q2. The drain of MOSFET Q2 is connected to the ground carrier signal receiving module, and the source of MOSFET Q2 is connected to the power supply VCC-1. The ground carrier signal receiving module is connected in parallel across the two ends of the series resistor R5 on the power supply side line, and the power supply port VDD-1 is connected to the MCU. The power supply VDD-1 of MCU1 is connected, and the output port MCU1-RXD of the ground carrier signal receiving module is connected to the RXD port of MCU1; the output of the power supply circuit unit is connected to the input of the power receiving circuit unit via a power line, and the input of the power receiving circuit unit is connected to the source of MOSFET Q3; the ground carrier signal transmitting module is connected to the gate and source of MOSFET Q3, and the power supply port VDD-2 is connected to the power supply VDD-2 of MCU2, and the input port MCU2-TXD of the ground carrier signal transmitting module is connected to the TXD port of MCU2; the ground carrier signal receiving module is connected in parallel across the two ends of resistor R12 on the power line of the power receiving side, and the power supply port VDD-2 is connected to the power supply VDD-2 of MCU2, and the output port MCU2-RXD of the ground carrier signal receiving module is connected to the RXD port of MCU2; the battery module is electrically connected to resistor R12, the measurement and control unit module, and MCU2, and MCU2 is signal-connected to the measurement and control unit module.

2. The downhole DC power supply and carrier communication circuit according to claim 1, characterized in that, The ground carrier signal transmission module includes at least transistor Q1, resistors R1, R2, and R3, capacitor C1, and diode D1; the emitter of Q1 is grounded, and the collector of Q1 is connected to the gate of MOSFET Q2 through resistor R1; the base of Q1 is connected to the input port MCU1-TXD and to power supply VDD-1 through resistor R2; one end of capacitor C1 is grounded, and the other end is connected to the base of Q1; one end of diode D1 is grounded, and the other end is connected to the base of Q1.

3. The downhole DC power supply and carrier communication circuit according to claim 1, characterized in that, The ground carrier signal receiving module includes at least an optocoupler U1, a resistor R4, a resistor R6, and a capacitor C2; one end of the secondary side of the optocoupler U1 is connected to the power port VDD-1 through the resistor R4, and the other end is connected to the output port MCU1-RXD; one end of the resistor R6 and the capacitor C2 are grounded, and the other end is connected to the output port MCU1-RXD.

4. The downhole DC power supply and carrier communication circuit according to claim 1, characterized in that, The well-download waveform signal transmission module includes at least transistor Q4, resistors R7, R8, and R9; the collector of Q4 is connected to the gate of Q3 through the series resistor R8, and is connected to the source of Q3 through the series resistors R8 and R7; the emitter of Q4 is grounded; the base of Q4 is connected to the input port MCU2-TXD, and is connected to the power supply port VDD-2 through resistor R9.

5. The downhole DC power supply and carrier communication circuit according to claim 1, characterized in that, The well-ground radio wave signal receiving module includes at least an optocoupler U2, resistor R10, resistor R11, capacitor C3, and resistor C4. The primary side of optocoupler U2 is connected to the drain of MOSFET Q3. One end of the secondary side of optocoupler U2 is connected to power supply VDD-2, and the other end is connected to the output port MCU2-RXD through resistor R11. One end of resistor R10 and capacitor C3 is grounded, and the other end is connected to the secondary side of optocoupler U2. One end of resistor C4 is grounded, and the other end is connected to the output port MCU2-RXD.

6. The downhole DC power supply and carrier communication circuit according to claim 1, characterized in that, The power receiving circuit unit also includes a resistor C5 and a diode D2; one end of the resistor C5 and the diode D2 is grounded, and the other end is connected to the battery module.

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