A downhole high-power and high-current electromagnetic transmitting device and working method

Abstract

The present disclosure provides an underground high-power and high-current electromagnetic transmitting device and a working method, the device comprising: a power supply and a plurality of parallel electromagnetic transmitting units connected to the power supply; the electromagnetic transmitting unit comprises a control module, a pulse signal waveform generator, a pulse output drive circuit, and a pulse shutoff and polarity conversion protection circuit connected in sequence; the control module controls the pulse signal waveform generator to generate a drive pulse according to a received waveform signal, the drive pulse is transmitted to the pulse output drive circuit, and the signal output by the pulse output drive circuit is then transmitted by driving an electromagnetic transmitting antenna after passing through a pulse shutoff and polarity conversion protection circuit; the device described in the present disclosure has a small size and weight, adopts a 36V standard DC power supply, and is convenient for underground work; high-power and high-current transmission is achieved by connecting multiple electromagnetic transmitting units in parallel.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electromagnetic launch devices, and in particular to an underground high-power and high-current electromagnetic launch device and a working method thereof. Background Art

[0002] The statements in this section merely provide background art related to the present disclosure and do not necessarily constitute prior art.

[0003] In order to detect the conditions under deeper strata, most electromagnetic transmitters used in ground geological exploration equipment use high voltage and high current methods to transmit electromagnetic signals, which inevitably makes the equipment very large and even requires a dedicated generator or generator truck to be used in conjunction.

[0004] The inventors found that in underground detection application scenarios, the operating space is greatly limited. For example, ground geological detection equipment is large in size and weight, and is difficult to carry underground. Generators or generator trucks cannot be used for power supply underground, and high-voltage power supply does not meet underground safety standards. Summary of the invention

[0005] In order to address the deficiencies in the prior art, the present invention provides an underground high-power and high-current electromagnetic transmitting device and a working method. The device has a small size and weight, and adopts a 36V standard DC power supply, which is convenient for underground work; high-power and high-current transmission is achieved by parallel connection of multiple electromagnetic transmitting units.

[0006] In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

[0007] A first aspect of the present disclosure provides an underground high-power and high-current electromagnetic transmitting device.

[0008] An underground high-power and high-current electromagnetic transmitting device comprises: a power supply and a plurality of parallel electromagnetic transmitting units connected to the power supply;

[0009] The electromagnetic transmitting unit includes a control module, a pulse signal waveform generator, a pulse output drive circuit, a pulse shutoff and polarity conversion protection circuit connected in sequence;

[0010] The control module controls the pulse signal waveform generator to generate a driving pulse according to the received waveform signal. The driving pulse is transmitted to the pulse output driving circuit. The signal output by the pulse output driving circuit is then transmitted by driving the electromagnetic transmitting antenna after passing through the pulse shutdown and polarity conversion protection circuit.

[0011] Furthermore, the electromagnetic transmitting unit also includes a transmitting current detection module and an output current adjustment circuit. The transmitting current detection module collects the output current signal in real time. The collected output current signal is sent to the external control terminal through the control module to monitor the output current value, and is fed back to the output current adjustment circuit in another way. When the output current value exceeds the preset value, the output current adjustment circuit shuts down the pulse output drive circuit.

[0012] Furthermore, when the driving signal pulse is turned off, the pulse shutoff and polarity conversion protection circuit provides a low impedance loop and is connected in parallel to the output terminal to absorb the electromagnetic energy stored in the electromagnetic transmitting antenna and the leakage current of the electronic switch with low impedance.

[0013] Furthermore, when the signal is normally transmitted, the pulse cutoff and polarity conversion protection circuit enters a high impedance state while starting to transmit the signal.

[0014] Furthermore, the control module synthesizes the received waveform signal to obtain a unipolar waveform signal or a bipolar waveform signal.

[0015] Furthermore, the power supply is a DC 36V power supply.

[0016] A second aspect of the present disclosure provides a working method of an underground high-power and high-current electromagnetic transmitting device.

[0017] A working method of a downhole high-power and high-current electromagnetic transmitting device, using the downhole high-power and high-current electromagnetic transmitting device described in the first aspect of the present disclosure;

[0018] The control module receives the waveform signal sent by the external control terminal;

[0019] The control module synthesizes the waveform signal according to the received waveform signal, and controls the pulse signal waveform generator to generate a driving pulse according to the generated waveform synthesis signal;

[0020] The driving pulse is transmitted to the pulse output driving circuit, and the signal output by the pulse output driving circuit is transmitted by driving the electromagnetic transmitting antenna after passing through the pulse shutoff and polarity conversion protection circuit.

[0021] Furthermore, the driving voltage of the pulse output driving circuit is adjusted to control the voltage value of the output driving waveform, so that the driving current output by each electromagnetic emitting unit is adjusted within a preset range.

[0022] Furthermore, the absorption time constant is determined by the equivalent inductance value of the electromagnetic transmitting antenna, the equivalent DC resistance value of the electromagnetic transmitting antenna, the distributed inductance value and the equivalent DC resistance value of the low impedance loop.

[0023] Furthermore, at the same time as the starting edge of the waveform signal is formed, the external control terminal outputs a falling edge through the synchronization signal output port and maintains a low level. The low level duration is 50% of the duration of the starting pulse of the waveform signal formed by the main control unit. When the low level duration is over, it flips to a high level.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. The electromagnetic transmitting device disclosed in the present invention has a small size and weight, adopts a 36V standard DC power supply, and is convenient for underground work; high-power and high-current transmission is achieved by connecting multiple electromagnetic transmitting units in parallel.

[0026] 2. In the electromagnetic transmitting device disclosed in the present invention, at the same time as the starting edge of the waveform signal is formed, the external control terminal outputs a falling edge through the synchronization signal output port and maintains a low level. The duration of the low level is 50% of the duration of the starting pulse of the waveform signal formed by the main control unit. When the low level duration is over, it flips to a high level, thereby achieving more precise and stable control.

[0027] 3. The electromagnetic launching device disclosed in the present invention controls the voltage value of the output driving waveform by adjusting the driving voltage of the pulse output driving circuit, so that the driving current output by each electromagnetic launching unit is adjusted within a preset range, thereby effectively ensuring the safety performance of the launching device.

[0028] Advantages of additional aspects of the present disclosure will be given in part in the following description and in part will become apparent from the following description or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure.

[0030] Figure 1 A schematic diagram of the structure of an underground high-power and high-current electromagnetic transmitting device provided in an embodiment of the present disclosure.

[0031] Figure 2 A logical relationship diagram of the waveform signal and synchronization signal provided in an embodiment of the present disclosure.

[0032] Figure 3 A logic block diagram of an electromagnetic transmitting unit provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0034] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0036] In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments may be combined with each other.

[0037] Example:

[0038] like Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of the present disclosure provides an underground high-power and high-current electromagnetic transmitting device, including a main control unit and multiple electromagnetic transmitting units, and the power supply is DC 36V.

[0039] Through the setting function of the main control unit, several electromagnetic transmitting units are selected to be enabled, and the electromagnetic transmitting units that are not enabled are in power-off mode; the main control unit also has the functions of waveform synthesis, configuration of the number of electromagnetic transmitting units, and synchronous signal output;

[0040] The main control unit forms a waveform signal according to the set waveform signal parameters, and the waveform signal is transmitted to the waveform signal input end of each enabled electromagnetic transmitting unit. The controller of the electromagnetic transmitting unit synthesizes and outputs the received waveform signal. The maximum amplitude of the output drive signal is ±36V. When combined with a matching electromagnetic transmitting antenna, it can output a maximum current of 20A. The DC impedance of the electromagnetic transmitting antenna is less than 1.8 ohms. At this time, the maximum output power of each electromagnetic transmitting unit is 720W; when all 10 of the above-mentioned electromagnetic transmitting units are enabled, the total maximum output power is 7200W, and the total maximum output current is 200A.

[0041] The selection of each electromagnetic transmitting unit is realized by the main control unit and the configuration function. The specific enabling / disabling of electromagnetic transmitting units is completed by the operator according to the range of the transmitting current. For example, if the total transmitting current is 110A, any 6 units can be configured to be enabled, or all 10 units can be configured to be enabled. The total current is evenly distributed to each unit, and the output current of each unit = total transmitting current / number of enabled units.

[0042] Because the sending device is a strong signal (for example, the sending current is above the ampere level) and is an active output, and the instrument casing is made of metal and takes good grounding measures, the input and output (such as the sending output terminal, power input terminal and other interfaces) have built-in anti-electromagnetic interference components or circuits, which can reduce the impact of external electromagnetic interference on the sending device to a minimum to ensure the normal operation of the instrument; for the influence of temperature and humidity, the instrument itself selects electronic components and accessories according to industrial-grade requirements. At the same time, the instrument adopts hardware compensation and software compensation mechanisms, so that the instrument can perform dynamic parameter compensation as the temperature and humidity fluctuate.

[0043] For the above-mentioned single electromagnetic transmitting unit, the driving voltage value of the pulse output driving circuit can be adjusted through the output current adjustment circuit, so that the driving voltage output by each electromagnetic transmitting unit can be adjusted between 2V and 36V, and the current driving the electromagnetic transmitting antenna can be adjusted between 1A and 20A, that is, the output power can be adjusted between 2W and 720W.

[0044] When the electromagnetic transmitting unit of this embodiment receives the waveform signal transmitted by the main control unit, the controller of the electromagnetic transmitting unit controls the pulse signal waveform generator to generate a driving pulse according to the waveform signal, and the driving pulse is transmitted to the pulse output driving circuit. The driving output signal is then connected to the driving output terminal after passing through the pulse shutoff and polarity conversion protection circuit;

[0045] The output current is sampled by the transmitting current detection component, and the collected current data is transmitted to the main control unit through the control signal data bus to monitor the output current value, and the other way is used to feed back to the output current adjustment circuit. When the output current value exceeds 10% of 20A, the output current adjustment circuit shuts down the drive output circuit to prevent damage to the output circuit.

[0046] Since the output pulse voltage of each transmitting unit is completed by the configuration of the main control unit, the voltage value of the output pulse is known. Combined with the collected transmitting current value, the power of the output pulse can be known. The output current / power of the accumulated enabled transmitting unit is the total transmitting current / power of the instrument.

[0047] Electronic switches have an inherent turn-off time constant. It is impossible to cut off the output of the electronic switch immediately when the output signal is turned off, and there is leakage current output in the pulse output drive circuit. In addition, the electromagnetic transmitting antenna generates a turn-off pulse and a freewheeling current during the turn-off time. The voltage value of the turn-off pulse is more than 8 times the drive voltage, which makes the actual turn-off time of the electronic switch much longer than the turn-off time constant of the electronic switch itself, causing long-term damped oscillation in the output signal waveform, resulting in errors and mistakes in the measurement.

[0048] The function of the pulse shutoff and polarity conversion protection circuit described in this embodiment is to provide a low impedance loop and connect it in parallel to the output terminal when the drive signal pulse is shut off. At this time, the electromagnetic energy stored in the electromagnetic transmitting antenna and the leakage current of the electronic switch can be absorbed with low impedance.

[0049] The absorption time constant of the system composed of the driving circuit and the electromagnetic transmitting antenna described in this embodiment is determined by (L+l)*(R+r), where L is the equivalent inductance value of the electromagnetic transmitting antenna, R is the equivalent DC resistance value of the electromagnetic transmitting antenna, l is the distributed inductance value of the above system, and the l value is much smaller than L, and r is the equivalent DC resistance value of the low impedance loop, and the r value is less than one hundred milliohms and much smaller than the R value. At this time, the absorption time constant is approximately LR, that is, the absorption time constant of the system composed of the various circuit modules described in this embodiment is determined by the characteristics of the electromagnetic transmitting antenna.

[0050] At the same time, when sending signals normally, the pulse shutdown and polarity conversion protection circuit enters a high impedance state while starting to send signals. The equivalent resistance is greater than 1M ohm, which is much greater than the impedance of the electromagnetic transmitting antenna and does not affect the output of normal signals.

[0051] When the main control unit described in this embodiment forms a waveform signal, at the same time as the starting edge of the waveform signal is formed, the main control unit outputs a falling edge through the synchronization signal output port and maintains a low level. The low level lasts for 50% of the duration of the starting pulse of the waveform signal formed by the main control unit, and flips to a high level when the low level duration expires.

[0052] In this embodiment, the following improvements are mainly considered:

[0053] (1) Try to meet the underground safety voltage requirements, and then combine other safety measures to ensure that the entire machine meets the underground safety requirements.

[0054] (2) Due to the low operating voltage, when driving a large loop antenna coil (length exceeding 100 meters or several hundred meters), the DC impedance of the coil cannot be greater than 36V / 20A=1.8 ohms. This is relatively easy to achieve. If the driving current is further increased, the cross-sectional area of ​​the antenna coil wire will increase a lot, and the total weight of the antenna will increase exponentially, causing the antenna cost to rise sharply and making it inconvenient to carry.

[0055] (3) The accumulation of multiple smaller output drive currents can achieve the purpose of large current output. At the same time, any electrical circuit has distributed parameters. Connecting multiple antenna coils in parallel is equivalent to improving the distributed parameters of the antenna coils. As long as the output port of the small current transmitting unit is matched with the antenna, the matching of the entire integrated antenna (that is, the superposition of multiple individual antennas) can be guaranteed. However, matching a large antenna with a very large current output port is much more difficult.

[0056] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, systems, or computer program products. Therefore, the present disclosure may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0057] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0058] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0059] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0060] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0061] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. An underground high-power and high-current electromagnetic transmitting device, characterized in that: include: A power supply and a plurality of parallel electromagnetic transmitting units connected to the power supply; The electromagnetic transmitting unit includes a control module, a pulse signal waveform generator, a pulse output drive circuit, a pulse shutoff and polarity conversion protection circuit connected in sequence; The control module controls the pulse signal waveform generator to generate a driving pulse according to the received waveform signal, and the driving pulse is transmitted to the pulse output driving circuit. The signal output by the pulse output driving circuit is then transmitted by driving the electromagnetic transmitting antenna after passing through the pulse shutoff and polarity conversion protection circuit; When the driving signal pulse is turned off, the pulse shutoff and polarity conversion protection circuit provides a low impedance loop and is connected in parallel to the output terminal to absorb the electromagnetic energy stored in the electromagnetic transmitting antenna and the leakage current of the electronic switch with low impedance; At the same time as the starting edge of the waveform signal is formed, the external control terminal outputs a falling edge through the synchronous signal output port and maintains a low level. The duration of the low level is 50% of the duration of the starting pulse of the waveform signal formed by the main control unit. When the low level duration is over, it flips to a high level. The electromagnetic transmitting unit also includes a transmitting current detection module and an output current adjustment circuit. The transmitting current detection module collects output current signals in real time. The collected output current signals are sent to an external control terminal through a control module to monitor the output current value, and the other way is fed back to the output current adjustment circuit. When the output current value exceeds a preset value, the output current adjustment circuit shuts down the pulse output drive circuit. The main control unit has a setting function, which selects and enables a number of electromagnetic transmitting units, and the electromagnetic transmitting units that are not enabled are in a power-off mode; the main control unit also has the functions of waveform synthesis, configuration of the number of electromagnetic transmitting units, and synchronous signal output; For a single electromagnetic transmitting unit, the driving voltage value of the pulse output driving circuit is adjusted through the output current adjustment circuit, so that the driving voltage output by each electromagnetic transmitting unit is adjusted between 2V and 36V, and the current driving the electromagnetic transmitting antenna is adjusted between 1A and 20A, and the output power is adjusted between 2W and 720W.

2. The underground high-power and high-current electromagnetic transmitting device according to claim 1, characterized in that: When the signal is normally transmitted, the pulse cutoff and polarity conversion protection circuit enters a high impedance state at the same time as the transmission signal is started.

3. The underground high-power and high-current electromagnetic transmitting device according to claim 1, characterized in that: The control module synthesizes the received waveform signal to obtain a unipolar waveform signal or a bipolar waveform signal.

4. The underground high-power and high-current electromagnetic transmitting device according to claim 1, characterized in that: The power supply is a DC 36V power supply.

5. A working method of an underground high-power and high-current electromagnetic transmitting device, using the underground high-power and high-current electromagnetic transmitting device according to any one of claims 1 to 4; The control module receives the waveform signal sent by the external control terminal; The control module synthesizes the waveform signal according to the received waveform signal, and controls the pulse signal waveform generator to generate a driving pulse according to the generated waveform synthesis signal; The driving pulse is transmitted to the pulse output driving circuit, and the signal output by the pulse output driving circuit is transmitted by driving the electromagnetic transmitting antenna after passing through the pulse shutoff and polarity conversion protection circuit.

6. The working method according to claim 5, characterized in that: The driving voltage of the pulse output driving circuit is adjusted to control the voltage value of the output driving waveform, so that the driving current output by each electromagnetic emitting unit is adjusted within a preset range.

7. The working method according to claim 5, characterized in that: The absorption time constant is determined by the equivalent inductance value of the electromagnetic transmitting antenna, the equivalent DC resistance value of the electromagnetic transmitting antenna, the distributed inductance value and the equivalent DC resistance value of the low impedance loop.

8. The working method according to claim 5, characterized in that: At the same time as the starting edge of the waveform signal is formed, the external control terminal outputs a falling edge through the synchronization signal output port and maintains a low level. The low level lasts for 50% of the duration of the starting pulse of the waveform signal formed by the main control unit. When the low level duration expires, it flips to a high level.

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