CN106199734A - It is applicable to double electromagnetics transmitter systems of M TEM probe technique - Google Patents

Abstract

The invention discloses a dual electromagnetic transmitter system suitable for the M-TEM detection method. The system includes a first transmitter, a second transmitter, a first power supply line, a second power supply line, a third power supply line, a first electrode, a second electrode, a first resistor, a second resistor, a third resistor and a fourth resistance, wherein: the first electrode is electrically connected to the first transmitter through the second resistance; the second electrode is electrically connected to the second transmitter through the fourth resistance; the first electrode also passes through one of the third power supply lines through the third resistance It is electrically connected with the second transmitter; the second electrode is also electrically connected with the first transmitter through the first resistor through the other line of the third power supply line; the first transmitter and the second transmitter are connected through the first power supply line and the second power supply line connection. The invention solves the problem that the traditional electromagnetic transmitter system easily distorts when the high-frequency current is emitted, because the electric current flowing through the power supply wire with the two twisted wires of the third power supply wire is equal in magnitude and opposite in direction, and the formed electromagnetic fields cancel each other out.

Description

Dual Electromagnetic Transmitter System for M-TEM Detection

technical field

The invention relates to the technical field of detection, in particular to a dual electromagnetic transmitter system suitable for the M-TEM detection method.

Background technique

M-TEM (Multi-Channel Transient Electromagnetic Detection) is to send pseudo-random coded current signals underground through a finite-length grounding wire current source, and simultaneously observe electromagnetic field responses and record emission currents within a certain range on the ground or ocean surface, through deconvolution Obtain the ground impulse response, calculate the apparent resistivity, and achieve the purpose of detecting geological targets with different buried depths in two-dimensional or three-dimensional manner. Usually, a high-power transmitter is used to transmit a pseudo-random coded current to realize large-distance transmission and reception and observation of the entire field signal. The transmitted pseudo-random encoded current waveform is a series of pulse signals with varying widths. However, due to the influence of the parasitic inductance of the power supply line in the existing transmitter system, the current waveform will be distorted when transmitting high-frequency current to the earth, which is not conducive to subsequent Forward and inverse calculation of signals. Since the transmission current distortion of a single transmitter system cannot be predicted, it can only be observed through waveform recording, and the continuous acquisition under high sampling rate (above 10KHz) for a long time brings great difficulties to the real-time processing and data storage of the system. The biggest difficulty is that if the emission current waveform is predictable, then it is enough to store the ground impulse response calculated in real time, which can not only solve the problem of data storage, but also solve the problem of data communication, and can also achieve the goal of real-time output of results, greatly reducing workload and improve work efficiency.

Contents of the invention

The main purpose of the present invention is to provide a dual electromagnetic transmitter system suitable for the M-TEM detection method, aiming at solving the current waveform when the traditional electromagnetic transmitter system transmits high-frequency current to the earth due to the influence of the parasitic inductance of the power supply line Distortion will occur, which is not conducive to the technical problems of subsequent forward and inverse calculations of signals.

To achieve the above object, the present invention provides a dual electromagnetic transmitter system suitable for the M-TEM detection method.

The dual electromagnetic transmitter system suitable for the M-TEM detection method includes a first transmitter, a second transmitter, a first power supply line, a second power supply line, a third power supply line, a first electrode, a second electrode, a second A resistor, a second resistor, a third resistor and a fourth resistor, wherein:

The first electrode is electrically connected to the first transmitter through the second resistor;

The second electrode is electrically connected to the second transmitter through the fourth resistor;

The first electrode is also electrically connected to the second transmitter through one of the third power supply lines through the third resistor;

The second electrode is also electrically connected to the first transmitter through the first resistor through another line of the third power supply line;

The first transmitter is connected to the second transmitter through a first power supply line and a second power supply line.

Preferably, the third power supply line is a power supply line in which two wires are twisted with each other.

Preferably, the first transmitter includes a first diesel generator, a first AC/DC rectification module, and a first transmitting module; the second transmitter includes a second diesel generator, a second AC/DC rectification module, Second launch module.

Preferably, the first electrode is electrically connected to the left bridge arm of the first transmitting module through the second resistor; the second electrode is electrically connected to the right bridge arm of the second transmitting module through the fourth resistor; The first electrode is electrically connected to the right bridge arm of the second transmitting module through one of the third power supply lines through the third resistor; the second electrode is also electrically connected through the third power supply line The other wire is electrically connected to the left bridge arm of the first transmitting module via the first resistor.

Preferably, the first electrode is electrically connected to the right bridge arm of the first transmitting module through the second resistor; the second electrode is electrically connected to the left bridge arm of the second transmitting module through the fourth resistor; The first electrode is electrically connected to the left bridge arm of the second transmitting module through one of the third power supply lines through the third resistor; the second electrode is also electrically connected through the third power supply line The other wire is electrically connected to the right bridge arm of the first transmitting module via the first resistor.

Preferably, both the first power supply line and the second power supply line realize unidirectional conduction through diodes.

Preferably, the diode is a high-power fast recovery diode or a Schottky diode.

Preferably, both the first end of the first power supply line and the first end of the second power supply line are electrically connected to the negative polarity of the DC bus of the first transmitter, and the second end of the first power supply line and the second end of the second power supply line are electrically connected to the negative polarity of the DC bus of the second transmitter.

Preferably, the transmission waveforms of the first transmitter and the second transmitter are synchronized, and the driving waveforms of the left bridge arm and the right bridge arm of the first transmitter and the left bridge arm and the right bridge arm of the second transmitter same.

Compared with the prior art, the dual electromagnetic transmitter system suitable for the M-TEM detection method provided by the present invention is equal in size and opposite in direction to the currents flowing through the power supply lines twisted with each other by the two wires of the third power supply line. The electromagnetic fields formed between them cancel each other out, and the parasitic inductance is greatly reduced, thereby reducing the influence of the parasitic inductance on the power supply line on the transmission current, solving the problem that the traditional electromagnetic transmitter system is easy to distort when transmitting high-frequency current, and realizing the transmission current waveform as The ideal pulse provides source support for subsequent forward and inversion calculations; due to the enhancement of high-frequency signals, the data of effective high-frequency frequency points can be greatly increased, which brings more data constraints for data forward and inverse interpretation, thus The resolution of data processing is improved; in addition, due to the presence of the current-limiting resistor, it can be guaranteed that the present invention is applicable to the double electromagnetic emission of the M-TEM detection method under the condition that the emission voltages of the first transmitter and the second transmitter are not strictly equal. The machine system will not be permanently damaged.

Description of drawings

Fig. 1 is a schematic diagram of the pseudo-randomly coded current waveform that the transmitter needs to emit when the M-TEM detection method is used;

Fig. 2 is the structural representation of the preferred embodiment of the dual electromagnetic transmitter system applicable to the M-TEM detection method of the present invention;

Fig. 3 is a schematic diagram of comparison of current waveforms emitted by the dual electromagnetic transmitter system applicable to the M-TEM detection method of the present invention and the traditional electromagnetic transmitter system.

detailed description

In order to further illustrate the technical means and effects of the present invention to achieve the above objectives, the specific implementation, structure, features and effects of the present invention will be described in detail below in conjunction with the accompanying drawings and preferred embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Referring to FIG. 1, FIG. 1 is a schematic diagram of a pseudo-random coded current waveform to be transmitted by a transmitter when the M-TEM detection method is used.

It can be seen from Figure 1 that when the M-TEM (Multi-channel Transient Electromagnetic Method) detection method is used, the emission current waveform is a series of pulse signals with varying widths. However, when the traditional transmitter is used to transmit the waveform, due to Due to the influence of the parasitic inductance of the power supply line, the current waveform will be distorted, so it is necessary to design an electromagnetic transmitter system suitable for the M-TEM detection method.

Referring to FIG. 2, FIG. 2 is a schematic structural diagram of a preferred embodiment of a dual electromagnetic transmitter system applicable to the M-TEM detection method of the present invention. In this embodiment, the dual electromagnetic transmitter system suitable for the M-TEM detection method includes a first transmitter 10, a second transmitter 20, a first power supply line 301, a second power supply line 302, a third power supply line 303, The first electrode 401 , the second electrode 402 , the first resistor R1 , the second resistor R2 , the third resistor R3 and the fourth resistor R4 .

The transmission waveforms of the first transmitter 10 and the second transmitter 20 are synchronized, and the left bridge arm and the right bridge arm of the first transmitter 10 and the left bridge arm and the right bridge arm of the second transmitter 20 The driving waveforms are the same. The module structure of the first transmitter 10 and the second transmitter 20 is the same as that of a traditional electromagnetic transmitter. That is, the first transmitter 10 includes a first generator 101, a first AC/DC rectifier module 102, and a first transmitter module 103; the second transmitter 20 includes a second generator 201, a second AC/DC rectifier module 202 and a second transmitting module 203 .

In this embodiment, the third power supply wire 303 is a power supply wire in which two wires are twisted with each other.

The first electrode 401 is electrically connected to the first transmitter 10 through the second resistor R2, as shown in FIG. 2 , in this embodiment, the first electrode 401 is connected to the first transmitter 10 through the second resistor R2. The left bridge arm of the first transmitting module 103 is electrically connected; the second electrode 402 is electrically connected to the second transmitter 20 through the fourth resistor R4, as shown in FIG. 2 , in this embodiment, the The second electrode 402 is electrically connected to the right bridge arm of the second transmitting module 203 through the fourth resistor R4; the first electrode 401 is also passed through one of the third power supply lines 303 through the third resistor R3 is electrically connected to the second transmitter 20; as shown in FIG. 2, in this embodiment, the first electrode 401 passes through one of the third power supply lines 303 through the third resistor R3 It is electrically connected to the right bridge arm of the second transmitting module 203; the second electrode 402 is also connected to the first transmitter 10 through the first resistor R1 through another line of the third power supply line 303 Electrical connection; as shown in FIG. 2, in this embodiment, the second electrode 402 also passes through another line of the third power supply line 303 and the first transmitting module 103 via the first resistor R1 The left bridge arm is electrically connected.

In other embodiments, the first electrode 401 is electrically connected to the right bridge arm of the first transmitting module 103 through the second resistor R2; the second electrode 402 is connected to the second transmitting module through the fourth resistor R4 The left bridge arm of 203 is electrically connected; the first electrode 401 is electrically connected to the left bridge arm of the second transmitting module 203 through one of the lines of the third power supply line 303 through the third resistor R3; The second electrode 402 is also electrically connected to the right bridge arm of the first transmitting module 103 through the other line of the third power supply line 303 via the first resistor R1.

The first transmitter 10 is connected to the second transmitter 20 through a first power supply line 301 and a second power supply line 302 . Both the first power supply line 301 and the second power supply line 302 realize unidirectional conduction through diodes. The number of diodes of the first power supply line 301 and the second power supply line 302 is set to one or two, so as to ensure the unidirectional conductivity of the power supply lines. The diode is a high-power fast recovery diode or a Schottky diode. As shown in Figure 2, in this embodiment, for the symmetry of the system, the first power supply line 301 is provided with two diodes, which are respectively D1 and D3, and the second power supply line 302 is provided with two diodes, which are respectively D2 and D4. Both the first end of the first power supply line 301 and the first end of the second power supply line 302 are electrically connected to the negative polarity (VH-) of the DC bus of the first transmitter 10, and the first power supply line Both the second end of 301 and the second end of the second power supply line 302 are electrically connected to the negative polarity (VH-) of the DC bus of the second transmitter 20 .

Referring to Fig. 2, the dual electromagnetic transmitter system applicable to the M-TEM detection method of the present invention has two current loops.

The first current loop is: first transmitter 10→second resistor R2→first electrode 401→earth→second electrode 402→fourth resistor R4→second transmitter 20→first power supply line 301 or second power supply Line 302 → first transmitter 10;

The second current loop is: the first transmitter 10→the first resistor R1→one of the third power supply lines 303→the second electrode 402→the earth→the first electrode 401→the other of the third power supply line 303 line→third resistor R3→second transmitter 20→second power supply line 302 or first power supply line 301→first transmitter 10.

For the second current loop, the currents flowing through the two twisted wires of the third power supply line 303 are equal in size and opposite in direction. The parasitic inductance is very small and can be ignored, which reduces the influence of the parasitic inductance on the power supply line on the emission current.

Referring to FIG. 3 , it is a schematic diagram showing the comparison of current waveforms emitted by the dual electromagnetic transmitter system applicable to the M-TEM detection method of the present invention and the traditional electromagnetic transmitter system.

In order to illustrate that the dual electromagnetic transmitter system applicable to the M-TEM detection method of the present invention can transmit pseudo-randomly coded current waveforms, a comparative experiment is carried out with the current waveforms emitted by the electromagnetic transmitter system.

The voltage at the DC bus is 500V, the grounding resistance is 50Ω, the equivalent inductance of a single AB pole pitch long power supply line is 2mH, and the transmission symbol frequency is 5th-order PRBS (Pseudo-Random Binary Sequences, pseudo-random code) code with a symbol frequency of 10KHz Type, the two electrodes are arranged at equal intervals, and the comparison diagram of the current waveform emitted by the dual electromagnetic transmitter system suitable for M-TEM detection method and the traditional electromagnetic transmitter system is shown in Figure 3.

As can be seen from Fig. 3, the current waveform emitted by the dual electromagnetic transmitter system applicable to the M-TEM detection method of the present invention can be guaranteed to be a bipolar PRBS code pattern in a stricter sense, and the magnitude of the emission current is slightly smaller than 10A , the reason is that four current limiting resistors (i.e. the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 in Fig. 2) are added to the current transmitting circuit. In this embodiment, the selected The current limiting resistors of the four current limiting resistors are all 1Ω. Although the current-limiting resistor is small, it can ensure that the present invention is applicable to the dual electromagnetic transmitter of the M-TEM detection method under the condition that the emission voltages of the two transmitters (the first transmitter 10 and the second transmitter 20) are not strictly equal. The system will not be permanently damaged.

Compared with the traditional electromagnetic transmitter system, the dual electromagnetic transmitter system suitable for the M-TEM detection method provided by the present invention is equal in magnitude and opposite in direction because the currents flowing through the power supply lines in which the two wires of the third power supply line are twisted to each other are equal and opposite. The electromagnetic fields formed between them cancel each other out, and the parasitic inductance is greatly reduced, thereby reducing the influence of the parasitic inductance on the power supply line on the emission current, solving the problem that the traditional electromagnetic transmitter system is easy to distort when emitting high-frequency current, and realizing the emission current The waveform is an ideal pulse, which provides source support for subsequent forward and inversion calculations; due to the enhancement of high-frequency signals, the data of effective high-frequency frequency points can be greatly increased, bringing more data constraints for data forward and inverse interpretation , thereby improving the resolution of data processing; in addition, due to the existence of the current-limiting resistor, it can be guaranteed that the present invention is applicable to the dual-mode detection method of the M-TEM detection method under the condition that the emission voltages of the first transmitter and the second transmitter are not strictly equal. The electromagnetic transmitter system will not be permanently damaged.

The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent function transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields , are all included in the scope of patent protection of the present invention in the same way.

Claims (8)

1. the double electromagnetics transmitter systems being applicable to M-TEM probe technique, it is characterised in that described in be applicable to M-TEM detection Double electromagnetics transmitter systems of method include the first transmitter, the second transmitter, the first supply lines, the second supply lines, the 3rd power supply Line, the first electrode, the second electrode, the first resistance, the second resistance, the 3rd resistance and the 4th resistance, wherein:

Described 3rd supply lines is the supply lines that both threads is the most stranded；

Described first electrode is electrically connected with described first transmitter by described second resistance；

Described second electrode is electrically connected with described second transmitter by described 4th resistance；

Described first electrode is launched with described second through described 3rd resistance also by the wherein single line of described 3rd supply lines Mechatronics；

Described second electrode also by the another single line of described 3rd supply lines through described first resistance and described first transmitter Electrical connection；

Described first transmitter is connected by the first supply lines and the second supply lines with described second transmitter.

It is applicable to double electromagnetics transmitter systems of M-TEM probe technique the most as claimed in claim 1, it is characterised in that described One transmitter includes the first diesel-driven generator, an AC/DC rectification module, the first transmitter module；Described second transmitter includes Second diesel-driven generator, the 2nd AC/DC rectification module, the second transmitter module.

It is applicable to double electromagnetics transmitter systems of M-TEM probe technique the most as claimed in claim 2, it is characterised in that described One electrode is electrically connected by the left brachium pontis of described second resistance and the first transmitter module；Described second electrode is by described 4th electricity Resistance electrically connects with the right brachium pontis of the second transmitter module；Described first electrode passes through the wherein single line of described 3rd supply lines through institute State the 3rd resistance to electrically connect with the right brachium pontis of described second transmitter module；Described second electrode is also by described 3rd supply lines Another single line electrically connects through the left brachium pontis of described first resistance with described first transmitter module.

It is applicable to double electromagnetics transmitter systems of M-TEM probe technique the most as claimed in claim 2, it is characterised in that described One electrode is electrically connected by the right brachium pontis of described second resistance and the first transmitter module；Described second electrode is by described 4th electricity Resistance electrically connects with the left brachium pontis of the second transmitter module；Described first electrode passes through the wherein single line of described 3rd supply lines through institute State the 3rd resistance to electrically connect with the left brachium pontis of described second transmitter module；Described second electrode is also by described 3rd supply lines Another single line electrically connects through the right brachium pontis of described first resistance with described first transmitter module.

It is applicable to double electromagnetics transmitter systems of M-TEM probe technique the most as claimed in claim 1, it is characterised in that described One supply lines and the second supply lines all realize one-way conduction by diode.

It is applicable to double electromagnetics transmitter systems of M-TEM probe technique the most as claimed in claim 5, it is characterised in that described two Pole pipe is high-power fast recovery diode or Schottky diode.

It is applicable to double electromagnetics transmitter systems of M-TEM probe technique the most as claimed in claim 1, it is characterised in that described First end of one supply lines and the first end of described second supply lines are all electric with the dc bus negative polarity of described first transmitter Connecting, the second end of described first supply lines and the second end of described second supply lines are all female with the direct current of described second transmitter Line negative polarity electrically connects.

8. the double electromagnetics transmitter systems being applicable to M-TEM probe technique as described in any one of claim 1 to 7, its feature exists In, the transmitted waveform of described first transmitter and described second transmitter synchronizes, and the left brachium pontis of described first transmitter and the right side The left brachium pontis of brachium pontis and the second transmitter is identical with the drive waveforms of right brachium pontis.