CN105510979A - Transient electromagnetic transmitter circuit with load in parallel connection for discharging - Google Patents
Transient electromagnetic transmitter circuit with load in parallel connection for discharging Download PDFInfo
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- CN105510979A CN105510979A CN201510859722.7A CN201510859722A CN105510979A CN 105510979 A CN105510979 A CN 105510979A CN 201510859722 A CN201510859722 A CN 201510859722A CN 105510979 A CN105510979 A CN 105510979A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
Abstract
The invention relates to a transient electromagnetic transmitter circuit with loads in parallel connection for discharging. The transient electromagnetic transmitter circuit comprises a DC power supply, an H bridge circuit, load coils, bidirectional switches, a load discharging loop and a constant-voltage clamping circuit, wherein the DC power supply is connected with the load coil N through the H bridge circuit, the load coil I, the bidirectional switch I, the load coil II, the bidirectional switch II...; the load coil I, the load coil II,...and the load coil N are each connected with the load discharging loop; and the load discharging loop is connected with the DC power supply through the constant-voltage clamping circuit. Compared with the prior art, by adopting the bidirectional switches and diodes, the load coils are in a series connection state when the current rises and is stable, and the load coils are in parallel connection state in discharging. The transient electromagnetic transmitter circuit effectively reduces equivalent inductance of the loads in discharging, reduces turn-off delay time of the transmitter, and reduces transient electromagnetic detection blind zone. The load coil segmentation method is flexible, and parallel load inductance value can be changed according to specific detection requirements. Under the condition of same turn-off delay time, the transmitting current or load coil number can be increased, the equivalent magnetic moment is enlarged, and the detection depth and resolution are increased.
Description
Technical field
The present invention relates to the transient electromagnetic detecting instrument circuit in a kind of geophysical exploration, especially can be applicable to the Transient Electromagnetic Transmitter circuit of various power grade.
Background technology
Transient electromagnetic detecting instrument is widely used in geophysical exploration field, usually be made up of transmitter and receiver, its investigation depth and detection accuracy are not only relevant with the factor such as sample rate, dynamic range, noiseproof feature of receiver, also relevant with the factor such as transmitter current, turn-off time, shutoff waveform of transmitter.Principle of work is as follows, the inductive load (as shown in Figure 2) that transmitter is formed to multiturn wire sends Bipolar current waveform (as shown in Figure 3), excite pulsatile once magnetic field, this primary field is transmitted to underground and encourages underground conducting medium to produce eddy current, when transmitter cut-off current thus when primary field is disappeared, the eddy current of induction can produce secondary field, and the secondary field produced can not disappear with primary field and disappear immediately, namely has a transient process.Utilize receiver to receive secondary field data, then by back analysis, study the variation relation of itself and time, thus the Electrical distribution structure of lower conductor and spatial shape definitely, know the information such as subsurface conductivity, stratal configuration.
Because primary field intensity is much larger than secondary field, when primary field does not disappear, the data of secondary field cannot be received with receiver.According to correlation theory, transient electromagnetic secondary field early signal reaction shallow-layer geological information, late period signal reaction deep geologic information.This causes the loss of the early stage secondary field signal reflecting shallow-layer geological information, makes transient electromagnetic detecting instrument there is certain detection blind area.In order to reduce detection blind area, require that the shutoff time delay of Transient Electromagnetic Transmitter is as far as possible short, the electric current namely in loading coil drop to zero time as far as possible short, current over pulse is as far as possible little and do not produce vibration.In addition, when detecting the geological information of comparatively depths (below 1km), need to produce larger magnetic moment, this can realize by increasing transmitter current or increasing coil turn, but increasing electric current or increasing the number of turn to bring again transmitter to turn off time delay increase, the problem that overshoot increases.Therefore, the key issue of Transient Electromagnetic Transmitter research mainly how to reduce turn off time delay, how to reduce current over pulse, how to suppress vibrate problem.
In order to solve the problem, people have found out a lot of way.As University Of Chongqing pays the grand energy-dissipating type constant voltage clamping circuit that proposes in 2006 " Proceedings of the CSEE " the 5th phase (05) P70-75 " two kinds novel quasi-resonance type current impulse shaping circuit " of will and energy regenerative type constant voltage clamping circuit, Jilin University Zhou Fengdao increases the method etc. of damping at the accelerating resistor that 2013 propose in " Jilin University's journal " the 4th phase (4) P1023-1028 " overshoot of time domain electromagnetic surveying transmitter current produces principle and suppression ".
These methods to some extent solve the problems referred to above, improve the performance of transmitter, reduce detection blind area.But the problems referred to above still exist.
Summary of the invention
Object of the present invention is exactly for above-mentioned the deficiencies in the prior art, in order to improve the performance of transmitter further, reducing detection blind area, increasing investigation depth, providing a kind of Transient Electromagnetic Transmitter circuit of load parallel discharge.
The object of the invention is to be achieved through the following technical solutions:
The Transient Electromagnetic Transmitter circuit of load parallel discharge, comprise direct supply, H-bridge circuit, loading coil, two-way switch, load discharge loop and constant voltage clamping circuit, through H-bridge circuit, loading coil I, two-way switch I, loading coil II and two-way switch II by direct supply ... be connected with loading coil N, loading coil I, loading coil II .... be connected with load discharge loop respectively with loading coil N, load discharge returns and connects and composes through constant voltage clamper energy feedback circuit and direct supply.
Two-way switch is connected with each circle loading coil, and make loading coil be in series connection when electric current rises and stablizes, coil is in parallel connection when discharging.
Every circle coil forms two-way discharge loop by four diodes, and one end of coil connects two diode D1 and D2, the negative electrode connecting coil of D1, and the anode of D1 connects the negative pole of direct supply, the anode connecting coil of D2, and the negative electrode of D2 connects clamp capacitor C2; The other end of coil connects two diode D3 and D4, the negative electrode connecting coil of D4, and the anode of D4 connects the negative pole of direct supply, the anode connecting coil of D3, and the negative electrode of D3 connects clamp capacitor C2.
Load parallel arrangement can adjust, the load be made up of N circle coil, according to actual demand, can be split as N number of single-turn circular coil in parallel, also can be split as N/2, and each two circle coils from parallel connection of coils connect.
Beneficial effect: compared with prior art its advantage is mainly in the present invention: effectively can shorten loading coil discharge time, reduce the shutoff time delay of transmitter, and then reduce transient electromagnetic detecting blind area.Loading coil segmented mode is flexible, can need to change according to concrete detection.Under same shutoff time delay, transmitter current or the load number of turns can be increased, increase equivalent magnetic moment, and then increase investigation depth and resolution.
Accompanying drawing illustrates:
Accompanying drawing 1: the Transient Electromagnetic Transmitter circuit structure block diagram of load parallel discharge
Accompanying drawing 2: Transient Electromagnetic Transmitter loading coil and equivalent circuit diagram thereof
Accompanying drawing 3: Transient Electromagnetic Transmitter ideal current waveform and actual current oscillogram
Accompanying drawing 4: load parallel discharge transmitter complete circuit
Accompanying drawing 5: the diode discharge loop structure figure of every circle coil
An accompanying drawing 6:n coil is by circle parallel circuit figure
Accompanying drawing 7: load forward discharge current loop diagram
Accompanying drawing 8: laod reversal discharge current loop diagram
Embodiment:
Below in conjunction with drawings and Examples, the present invention is described in further detail:
The Transient Electromagnetic Transmitter circuit of load parallel discharge, comprise direct supply, H-bridge circuit, loading coil, two-way switch, load discharge loop and constant voltage clamping circuit, through H-bridge circuit, loading coil I, two-way switch I, loading coil II and two-way switch II by direct supply ... be connected with loading coil N, loading coil I, loading coil II .... be connected with load discharge loop respectively with loading coil N, load discharge returns and connects and composes through constant voltage clamper energy feedback circuit and direct supply.
Two-way switch is connected with each circle loading coil, and make loading coil be in series connection when electric current rises and stablizes, coil is in parallel connection when discharging.
Every circle coil forms two-way discharge loop by four diodes, and one end of coil connects two diode D1 and D2, the negative electrode connecting coil of D1, and the anode of D1 connects the negative pole of direct supply, the anode connecting coil of D2, and the negative electrode of D2 connects clamp capacitor C2; The other end of coil connects two diode D3 and D4, the negative electrode connecting coil of D4, and the anode of D4 connects the negative pole of direct supply, the anode connecting coil of D3, and the negative electrode of D3 connects clamp capacitor C2.
Load parallel arrangement can adjust, the load be made up of N circle coil, according to actual demand, can be split as N number of single-turn circular coil in parallel, also can be split as N/2, and each two circle coils from parallel connection of coils connect.
Circuit structure:
Transient Electromagnetic Transmitter load is made up of coil usually, the large perception of tool, low loop resistance feature, launches magnetic moment and is proportional to coil equivalent area and transmitter current.For inductive load, inductance value is larger, turn off time delay longer, in order to reduce load inductance amount, ground Transient Electromagnetic Transmitter load is made up of the large coil of single turn usually, but in aviation transient electromagnetic and marine transient electromagnetic field, due to operation easier and environmental limit, usually can not arrange the large coil of single turn as ground load, but obtain the magnetic moment wanted using multiturn small coil as load.Usual loading coil can be equivalent to the structure of inductance and resistant series, and four circle coils and equivalent electrical circuit thereof are as shown in Figure 2.
Transmitter adopts H-bridge circuit to send current waveform as shown in Figure 3 to loading coil, desirable current waveform does not turn off time delay, but because the inductive discharge of loading coil equivalence needs the time, therefore actual current needs through just dropping to zero after a while, as shown in T in accompanying drawing 3, this is the shutoff time delay of transmitter.Consider situation when loading coil is two circle, the complete circuit of transmitter as shown in Figure 4, uses two-way switch by two circle coils separately.Two-way switch is in series by the IGBT module of two band anti-parallel diodes, and two IGBT common emitters connect.Electric current forward flows through VT5 and D9, and the control signal of VT5 is consistent with VT1, VT4 control signal, VT5 also conducting during VT1, VT4 conducting, two coils connected in series chargings, while VT1, VT4 turn off, control VT5 turns off, and can disconnect two circle coils, make two coils become parallel connection from series connection; Inverse current flows through VT6 and D8, and the control signal of VT6 is consistent with VT2, VT3 control signal, VT6 also conducting during VT2, VT3 conducting, two coils connected in series chargings, while VT2, VT3 turn off, control VT6 turns off, and can disconnect two circle coils, make two coils become parallel connection from series connection.By diode for every circle coil provides two-way discharge loop, the diode discharge loop structure of every circle coil as shown in Figure 5, one end of coil connects two diodes D1, D2, wherein D1 negative electrode connecting coil, anode connects the negative pole of direct supply, the anode connecting coil of D2, negative electrode connects clamp capacitor C2.The diode connection of the other end of coil and other coil end points is the same with D1, D2.The effect of diode is for load discharge provides loop, and Limited Current direction.
Consider situation when loading coil is n circle, specifically as shown in Figure 6.There are two diodes on every circle coil both sides, because two of H bridge lower brachium pontis are parallel with diode, the coil being in two ends only needs three diodes, in addition, often increases by a circle, just need increase two-way switch and four diodes.The concrete number of turn and the segmentation situation of loading coil are determined by the real needs of transmitter design, and such as, the load that 8 circle coils are formed, can be divided into two sections, every section of four circles, need a two-way switch and six diodes; Also four sections be can be divided into, every section of two circles, so just three two-way switchs and 14 diodes needed; Can also continue to be subdivided into eight sections, every section of circle, need seven two-way switchs and 30 diodes.Other segmented modes can also be selected, until travel through all combinations.
Circuit working principle:
According to the transmitted waveform shown in accompanying drawing 3, if switch VT1, VT4, VT5 conducting during t=0, transmitter is started working, during t=T/4, VT1, VT4, VT5 turn off, do not consider the turn-off time of switch VT1, VT4, VT5, now loading coil begins through diode to the electric discharge of clamp capacitor C2 forward, and concrete discharge loop as shown in Figure 7.The discharge loop of inductance L 1 is L1-D3-C2-VT3-R1-L1; The discharge loop of inductance L 2 is L2-D7-C2-D5-R2-L2.This is forward discharge loop.During t=2T/4, switch VT2, VT3, VT6 conducting, power supply is provided with inverse current to load, and during t=3T/4, VT2, VT3, VT6 turn off, and do not consider the turn-off time of VT2, VT3, VT6, now loading coil back discharge, concrete discharge loop as shown in Figure 7.The discharge loop of inductance L 1 is L1-R1-D2-C2-D4-L1; The discharge loop of inductance L 2 is L2-R2-D6-C2-VT4-L2.Later each cycle repeats above-mentioned discharge process.
Suppose that loading coil is two circles, every circle inductance value is 1mH, coefficient of mutual inductance M=0.5, can be obtained, equivalent inductance when two circles series connection by inductance series connection formula
Ls＝L1+L2+2M＝3mH(1)
Equivalent inductance time in parallel
Visible when inductance becomes parallel connection from series connection, its equivalent electric sensibility reciprocal can obviously diminish.By rlc circuit time constant
transmitter discharge loop is rlc circuit, and turn off time delay T and be proportional to τ and then be proportional to load equivalent inductance value L, known and existing transmitter load discharged in series is compared, and the parallel discharge time can obviously reduce, and then the shutoff time delay of transmitter also can obviously reduce.This circuit of present consideration is to the improved action of existing transmitter: if keep transmitter load area coil and the number of turn constant, then can reduce equivalent electric sensibility reciprocal after changing said structure into, so reduce transmitter turn off time delay, reduce detection blind area; If it is constant to keep turning off time delay, then can increases transmitter current or increase coil turn, and then increasing investigation depth and the resolution of transient electromagnetic apparatus.
Claims (4)
1. the Transient Electromagnetic Transmitter circuit of a load parallel discharge, comprise direct supply, H-bridge circuit, loading coil, two-way switch, load discharge loop and constant voltage clamping circuit, it is characterized in that, through H-bridge circuit, loading coil I, two-way switch I, loading coil II and two-way switch II by direct supply ... be connected with loading coil N, loading coil I, loading coil II .... be connected with load discharge loop respectively with loading coil N, load discharge returns and connects and composes through constant voltage clamper energy feedback circuit and direct supply.
2. the Transient Electromagnetic Transmitter circuit of load parallel discharge according to claim 1, it is characterized in that, two-way switch is connected with each circle loading coil, and make loading coil be in series connection when electric current rises and stablizes, coil is in parallel connection when discharging.
3. the Transient Electromagnetic Transmitter circuit of load parallel discharge according to claim 1, it is characterized in that, every circle coil forms two-way discharge loop by four diodes, one end of coil connects two diode D1 and D2, the negative electrode connecting coil of D1, the anode of D1 connects the negative pole of direct supply, the anode connecting coil of D2, and the negative electrode of D2 connects clamp capacitor C2; The other end of coil connects two diode D3 and D4, the negative electrode connecting coil of D4, and the anode of D4 connects the negative pole of direct supply, the anode connecting coil of D3, and the negative electrode of D3 connects clamp capacitor C2.
4. the Transient Electromagnetic Transmitter circuit of load parallel discharge according to claim 1, is characterized in that, load parallel arrangement can adjust, the load be made up of N circle coil, according to actual demand, can be split as N number of single-turn circular coil in parallel, also can be split as N/2, each two circle coils from parallel connection of coils connect.
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Cited By (8)
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| CN107991708A (en) * | 2018-01-29 | 2018-05-04 | 中国科学院电子学研究所 | A kind of bipolarity triangular wave transient electromagnetic emission system |
| CN108572339A (en) * | 2017-03-08 | 2018-09-25 | 北京卫星环境工程研究所 | It reduces environmental magnetic field interference and the method influenced is measured on magnetic flux method |
| CN111313916A (en) * | 2020-03-31 | 2020-06-19 | 湖南科技大学 | Signal transmitting device and method for reducing transient electromagnetic turn-off time |
| CN112649883A (en) * | 2020-12-16 | 2021-04-13 | 吉林大学 | Method for measuring and extracting parameters of time-varying grounding load of electrical source |
| CN111352164B (en) * | 2020-03-20 | 2021-04-23 | 吉林大学 | Transient electromagnetic detection system with large transmitting magnetic moment and short turn-off time |
| CN112983402A (en) * | 2021-02-05 | 2021-06-18 | 中国矿业大学(北京) | Real-time early warning device and method for transient electromagnetic advanced intelligent detection while drilling in underground drilling |
| CN114812791A (en) * | 2022-04-25 | 2022-07-29 | 西南交通大学 | Shock wave position and waveform sensor based on parallel resistor array |
| CN116500692A (en) * | 2023-06-26 | 2023-07-28 | 吉林大学 | Optimization method for small loop transient electromagnetic detection |
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Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108572339A (en) * | 2017-03-08 | 2018-09-25 | 北京卫星环境工程研究所 | It reduces environmental magnetic field interference and the method influenced is measured on magnetic flux method |
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| CN107991708A (en) * | 2018-01-29 | 2018-05-04 | 中国科学院电子学研究所 | A kind of bipolarity triangular wave transient electromagnetic emission system |
| CN111352164B (en) * | 2020-03-20 | 2021-04-23 | 吉林大学 | Transient electromagnetic detection system with large transmitting magnetic moment and short turn-off time |
| US11762122B2 (en) | 2020-03-31 | 2023-09-19 | Hunan University Of Science And Technology | Device and method for reducing turn-off time of transient electromagnetic transmitting signal |
| CN111313916A (en) * | 2020-03-31 | 2020-06-19 | 湖南科技大学 | Signal transmitting device and method for reducing transient electromagnetic turn-off time |
| CN111313916B (en) * | 2020-03-31 | 2024-03-08 | 湖南科技大学 | Signal transmitting device and method for reducing transient electromagnetic turn-off time |
| WO2021197367A1 (en) * | 2020-03-31 | 2021-10-07 | 湖南科技大学 | Signal transmitting device and method for reducing transient electromagnetic turn-off time |
| CN112649883A (en) * | 2020-12-16 | 2021-04-13 | 吉林大学 | Method for measuring and extracting parameters of time-varying grounding load of electrical source |
| CN112649883B (en) * | 2020-12-16 | 2021-11-23 | 吉林大学 | Method for measuring and extracting parameters of time-varying grounding load of electrical source |
| CN112983402B (en) * | 2021-02-05 | 2023-03-03 | 中国矿业大学(北京) | Real-time early warning device and method for transient electromagnetic advanced intelligent detection while drilling in underground drilling |
| CN112983402A (en) * | 2021-02-05 | 2021-06-18 | 中国矿业大学(北京) | Real-time early warning device and method for transient electromagnetic advanced intelligent detection while drilling in underground drilling |
| CN114812791A (en) * | 2022-04-25 | 2022-07-29 | 西南交通大学 | Shock wave position and waveform sensor based on parallel resistor array |
| CN114812791B (en) * | 2022-04-25 | 2024-01-30 | 西南交通大学 | Shock wave position and waveform sensor based on parallel resistor array |
| CN116500692A (en) * | 2023-06-26 | 2023-07-28 | 吉林大学 | Optimization method for small loop transient electromagnetic detection |
| CN116500692B (en) * | 2023-06-26 | 2023-10-27 | 吉林大学 | Optimization method for small loop transient electromagnetic detection |
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Application publication date: 20160420 |