CN111751867A

CN111751867A - Seismic source exciter

Info

Publication number: CN111751867A
Application number: CN202010680229.XA
Authority: CN
Inventors: 尤桃如; 沈新明; 朱罡; 杜珊珊; 杨贵祥; 仲伯军; 周月; 沐敏; 沈开阊
Original assignee: Jiangsu Taida Electromechanical Equipment Co ltd
Current assignee: Jiangsu Taida Electromechanical Equipment Co ltd
Priority date: 2020-07-15
Filing date: 2020-07-15
Publication date: 2020-10-09

Abstract

The invention discloses a seismic source exciter which comprises a power supply module, a voltage stabilizing circuit, a DC/AC conversion module, an alternating current boosting module, a high-voltage rectifying circuit, a GPS or Beidou module, a frequency division driving circuit and a detonation circuit DC/AC conversion module, wherein the DC/AC conversion module is used for converting DC direct current into AC alternating current; the alternating current boosting module is used for boosting the low-voltage alternating current into high-voltage alternating current; the high-voltage rectifying circuit is used for rectifying the high-voltage AC into high-voltage DC and storing the high-voltage DC; the GPS or Beidou module is used for providing a precise GPS or Beidou time reference pulse signal; the frequency division driving circuit is connected with the GPS or Beidou module and is used for outputting the time reference frequency division driving signal to the high-voltage detonation circuit; the detonating circuit is used for detonating the detonator explosive under the action of the reference pulse signal. The invention adopts the GPS or Beidou module, and the GPS or Beidou is used as the time reference for excitation, so that the time precision is high.

Description

Seismic source exciter

Technical Field

The invention belongs to the seismic detection technology, and particularly relates to a seismic source exciter.

Background

As a seismic source synchronizer used in seismic exploration equipment, the conventional seismic source synchronizer still used in conventional wired cable equipment at present makes the seismic source synchronizer and node type seismic data acquisition quite incompatible in field construction (data acquisition), directly results in the reduction of node type seismic exploration field construction (data acquisition) efficiency, increases node type seismic exploration field construction (data acquisition) cost, and makes the field construction (data acquisition) advantages of node type seismic data acquisition not fully and fully exerted, and the main reasons are as follows:

the seismic source synchronizer is a device for initiating the seismic source excitation point (shot point) and starting acquisition of seismic data, and the device establishes a precise synchronous relation between the seismic source excitation point (shot point) and the seismic data in time, and is essential equipment in field construction (data acquisition) of seismic exploration. The conventional seismic source synchronizer consists of two parts: the system comprises an encoder and a decoder, wherein the encoder and a central unit of the seismic data acquisition system are placed together, are arranged on an instrument vehicle and are operated by an instrument operator; the decoder is placed at the source firing point (shot point) and operated by the explorator, at a distance from the source firing point, to communicate and transmit the relevant signals using the radio station.

The working process of the conventional seismic source synchronizer is as follows: when a seismic data acquisition system central unit (usually installed on an instrument vehicle) works normally, seismic data receiving units (detectors and acquisition stations) on a survey line are checked, and when the seismic data acquisition (blasting) conditions are met, an instrument operator informs a seismic source excitation point (shot point) exploder to prepare for excitation (blasting), and if all the works before the excitation point (shot point) is detonated are ready, the instrument operator sends out a command by using an encoder: the preparation code (a special command signal) is transmitted to a decoder of a seismic source excitation point (shot point) through a radio station, an exploder on the seismic source excitation point (shot point) charges the decoder after receiving the preparation command signal, the charging time is usually 5 seconds, sufficient initiation electric energy can be provided for the initiation of the detonator, and after 5 seconds, an instrument operator sends a command by using an encoder: an ignition command signal (also a special command signal), which is a series of synchronous codes (usually 200ms) and is also transmitted to a decoder at a seismic source excitation point (shot point) via a radio station, wherein after the decoder under the control of an exploder at the seismic source excitation point (shot point) receives the ignition command signal, the decoder can decode the synchronous codes to form a synchronous zero signal, and the synchronous zero signal is taken as a time base point, so that both the encoder and the decoder establish a time synchronization relationship, both the encoder and the decoder use the synchronous zero signal as their respective time reference points, and start from this, after delaying for a same time (usually 400ms), both the encoder and the decoder each send an execution command after the arrival of the same delay time: the decoder on the seismic source excitation point (shot point) is a detonation instruction, and the encoder on the central unit end is a starting instruction. Then, the seismic source excitation point (shot point) detonates the detonator explosive at the moment under the action of the detonation instruction, and successfully excites the seismic source. Meanwhile, the central unit end starts to acquire the seismic data at the moment under the action of the starting instruction of the encoder, so that the following steps are shown: the initiation of the excitation point (shot point) and the collection of seismic data by the central unit are carried out at the same time, so that the excitation of the excitation point (shot point) and the reception of the receiving point (geophone and collection station) are carried out at the same time, the two sides are in an accurate synchronous relationship, and the error is +/-1 ms according to the seismic exploration industry standard. The conventional source synchronizer operates as shown in fig. 1.

It is obvious from the above working principle that the conventional seismic source synchronizer still has the following disadvantages in working:

the method has the disadvantages that 1, the method is complicated, no matter an instrument operator or an exploder needs to be trained by related technologies, the operation can be carried out after the professional skills are mastered, and the whole operation process is long.

The drawback 2 is that the encoder and the decoder are communicated through a radio station, and the encoder and the decoder have complex circuits, so that the stability and the reliability are not very high.

The disadvantage 3 is that the normal work between the encoder and the decoder is communicated through the radio station, so that the distance between an excitation point (shot point) and a receiving point is increased along with the increase of the number of acquisition stations, and when the distance is greater than the effective communication distance of the radio station, the conventional seismic source synchronizer cannot work normally. Once this occurs, it has only been solved by moving the central unit, i.e. the instrument truck, to shorten the distance between the excitation point (shot) and the central unit. The problem is that as the seismic exploration work is carried out in the field, no convenient traffic road exists under most conditions, the moving of a central unit, namely an instrument vehicle, usually needs to spend a large amount of time, the effective working time of field construction (data acquisition) is greatly shortened actually, and the following results are that: since the effective working time is shortened, the field construction (data acquisition) efficiency is reduced, and the field construction operation cost is increased.

Disclosure of Invention

The invention aims to provide a seismic source exciter.

The technical solution for realizing the purpose of the invention is as follows: a seismic source exciter comprises a power supply module, a voltage stabilizing circuit, a DC/AC conversion module, an alternating current boosting module, a high-voltage rectifying circuit, a GPS or Beidou module, a frequency division driving circuit and an initiation circuit, wherein the power supply module, the voltage stabilizing circuit, the DC/AC conversion module, the alternating current boosting module, the high-voltage rectifying circuit and the initiation circuit are sequentially connected, and the frequency division driving circuit is connected with the GPS or Beidou module and used for outputting time reference frequency division driving signals to the high-voltage initiation circuit.

Preferably, the DC/AC conversion module is configured to convert a direct current into an alternating current, and includes a PWM pulse width modulation converter U1, a timing resistor RT, 2 timing capacitors Ct, a field effect power amplifier switching tube Q2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a transistor Q1, a capacitor C7, an inductor L, a diode D3, a resistor Rs, a capacitor Css, and a resistor RD; the pin + ERR of the PWM converter U1 is connected with one end of a resistor R3, the other end of the resistor R3 is connected with one end of a resistor R1, one end of a resistor R2 and one end of a capacitor, the other end of the capacitor and the other end of a resistor R1 are connected with one end of a resistor R4, the other end of the resistor R4 is connected with the pin-ERR of the PWM converter U1 and a collector of a triode Q1, and the other end of the resistor R2 is connected with the pin Vref of the PWM converter U1; the pin Comp and the pin-ERR of the PWM converter U1 are connected through a capacitor; a pin Css of the PWM converter U1 is connected with one end of a capacitor Css, and the other end of the capacitor Css is connected with the negative electrode of a power supply; one end of the resistor R4 is connected with the negative pole of the power supply; a pin RD of the PWM converter U1 is connected with a power supply cathode through a resistor RD, a pin GND of the PWM converter U1 is connected with the power supply cathode, a pin RT of the PWM converter U1 is connected with the power supply cathode through a timing resistor RT, a pin Ct of the PWM converter U1 is sequentially connected with 2 timing capacitors Ct, the timing capacitors Ct are connected with pins + Vcc and + Vc of the PWM converter U1, capacitors and resistors R6 are connected between a pin-Cs and the pins + Cs of the PWM converter U1 in parallel, one end of the resistor R7 is connected with one end of the resistor R6, the other end of the resistor R8 is connected with one end of the field effect power amplifier Q2, and the other end of the resistor R8 is connected with the other end of the resistor R6; the grid of the field effect power amplifier switch tube Q2 is connected with one end of a resistor R9, the other end of the resistor R9 is connected with a pin OutA of a PWM (pulse-width modulation) converter U1, the drain of the field effect power amplifier switch tube Q2 is connected with one end of a resistor R10 and the anode of a diode D3 through a capacitor, the other end of the resistor R10 is connected with one end of a capacitor C7, the cathode of a diode D3 is connected with the other end of a capacitor C7 and one end of a resistor Rs, the other end of the resistor Rs is connected with one end of a resistor R5 and the emitter of a triode Q1, the other end of the resistor R5 and the base of the triode Q1 are connected with one end of a capacitor C7 as output ends, and the pin Vcc + of the PWM converter U1 is connected with one.

Preferably, the alternating current boosting module comprises a high-frequency pulse transformer T1, and the working frequency of the high-frequency pulse transformer T1 is 15 KHz-25 KHz.

Preferably, the high-voltage rectification circuit comprises a rectification diode D1, a rectification diode D2, a resistor R11, a resistor R12, an energy storage capacitor C21 and an energy storage capacitor C22, the positive end of the rectification diode D1 is connected with one end of the secondary coil of the high-frequency pulse transformer T1, the negative end of the rectification diode D1 is connected with the positive end of the energy storage capacitor C21 and one end of the resistor R11, the negative end of the rectification diode D2 is connected with the other end of the secondary coil of the high-frequency pulse transformer T1, the positive end of the rectification diode D2 is connected with the negative end of the high-voltage energy storage capacitor C22 and one end of the resistor R6327, the other end of the resistor R11 is connected with the other end of the resistor R12 and is simultaneously connected with the center tap of the secondary coil of the high-frequency pulse transformer T42 and the connection point of the negative end of the high-voltage energy storage capacitor.

Preferably, the detonation circuit comprises a triode Q4, a pulse transformer T2, a thyristor Q5, a resistor R21, a diode D5, a resistor R22, a resistor R23, a resistor R24 and a resistor R25, a base of the triode Q4 is connected with an output end of the frequency division driving circuit through a resistor R21, an emitter of the triode Q4 is grounded, a collector of the triode Q4 is connected with one end of a primary coil of the pulse transformer T2 and a positive end of the diode D5, the other end of the primary coil of the pulse transformer T2 is connected with a negative end of the diode D2 and with a positive power supply, the resistor R2 and the resistor R2 form a voltage divider, the resistor R2 is connected in parallel with a capacitor, one end of the resistor R2 is connected with a negative end of an energy storage capacitor C2 and one end of a secondary coil of the pulse transformer T2, one end of the resistor R2 is connected with the other end of the secondary coil of the pulse transformer T2, the other end of the resistor R2 is connected with one end of the resistor R, the anode of the controlled silicon Q5 is connected with one output end of the high-voltage rectifying circuit through a resistor R24, and the cathode of the controlled silicon Q5 is connected with the other output end of the high-voltage rectifying circuit.

Compared with the prior art, the invention has the following remarkable advantages: the invention has simple integral structure: the whole device consists of a battery, a GPS or Beidou, a circuit board, a switch and a shockproof, impact-resistant, waterproof and dustproof shell, so that the device has the advantages of small volume, light weight, wide temperature range, power saving, good stability, high reliability, convenience in operation and safety in use; the invention meets the seismic exploration industry standard and completely meets the requirements of seismic exploration on a seismic source exciter;

the invention adopts a GPS or Beidou module, the GPS or Beidou is used as a time reference for excitation, a receiving point also uses the GPS or Beidou time as a reference, only the GPS or Beidou time for detonation of an excitation point (shot point) and the GPS or Beidou time for starting acquisition of the receiving point need to be accurately obtained, the GPS or Beidou time and the receiving point establish an accurate synchronous relation in time, and the GPS or Beidou time accuracy can reach nS (10) because the GPS or Beidou time accuracy can reach nS^-9Seconds), pS (10)^-12Seconds) order much higher than mS (10)^-3Second) order, meets the seismic exploration industry standard on the time precision, is superior to the seismic exploration industry standard, and is completely feasible

The present invention is described in further detail below with reference to the attached drawings.

Drawings

FIG. 1 is a schematic diagram of a seismic source synchronizer operating in the prior art.

Fig. 2 is a schematic diagram of the working process of the present invention.

Fig. 3 is a schematic block diagram of the present invention.

FIG. 4 is a circuit diagram of a voltage regulator circuit and a DC/AC conversion module according to the present invention.

Fig. 5 is a schematic diagram of the detonation circuit of the present invention.

FIG. 6 is a schematic diagram of a high voltage display circuit.

Detailed Description

As shown in fig. 2 and 3, the seismic source exciter comprises a power supply module, a voltage stabilizing circuit, a DC/AC conversion module, an alternating current boosting module, a high voltage rectifying circuit, a GPS or beidou module, a frequency division driving circuit and an initiation circuit, wherein the power supply module, the voltage stabilizing circuit, the DC/AC conversion module, the alternating current boosting module, the high voltage rectifying circuit and the initiation circuit are sequentially connected, and the DC/AC conversion module is used for converting DC into AC; the alternating current boosting module is used for boosting the low-voltage alternating current into high-voltage alternating current; the high-voltage rectifying circuit is used for rectifying high-voltage AC alternating current into high-voltage DC direct current and storing the high-voltage DC direct current; the GPS or Beidou module is used for providing a precise GPS or Beidou time reference pulse signal; the frequency division driving circuit is connected with the GPS or Beidou module and is used for outputting the time reference frequency division driving signal to the high-voltage detonation circuit; the detonation circuit is used for detonating detonator explosives under the action of the reference pulse signal.

The GPS or Beidou module provides an accurate time reference, obtains required pulse signals at each time interval after passing through the frequency division circuit, and outputs the pulse signals to the high-voltage detonation circuit after being driven by the driving circuit so as to control the detonation of the detonator explosive at accurate time. The DC/AC conversion module converts low-voltage direct current provided by the battery into alternating current, the low-voltage alternating current is boosted by the voltage boosting of the transformer to be converted into high-voltage alternating current, the high-voltage alternating current is rectified into high-voltage direct current after being rectified by the high-voltage rectifying circuit, the energy of the high-voltage direct current is stored in the energy storage capacitor, the high-voltage direct current is instantly discharged to a detonator under the control of GPS or Beidou reference time pulse, detonator explosive is detonated, and seismic source excitation is completed.

As shown in fig. 4, in a further embodiment, the voltage stabilizing circuit is configured to provide a stable dc voltage to the whole power supply module after stabilizing the voltage of the power supply module. The method specifically comprises the following steps: the field effect power amplifier comprises a field effect power amplifier tube Q3(IRF9541), a voltage stabilizing diode D4(1N758), and a capacitor C3(100 muf/100V).

The negative end of the voltage stabilizing diode D4 is connected with the source electrode of the field effect power amplifying tube Q3 and is connected with the positive end of the battery, and the battery provides input voltage, namely the input voltage of the stabilized voltage power supply; the drain of the field effect power amplifier Q3 is connected to the load, i.e., the output voltage of the regulated power supply, to supply power to the load.

The working principle of the voltage stabilizing circuit is as follows: since the positive terminal of the zener diode D4 is connected to the gate of the fet Q3, the voltage is stable, and therefore the drain output voltage of the fet Q3 is a stable voltage output.

Specifically, the field effect power amplifier Q3 is P-channel MOSFET field effect power amplifier IRF9541 (main parameter: 60V/19A/125W), or IRF9531 (main parameter: 60V/12A/75W), zener diode 1N758(Vz10V, 20mA, 400mW), and capacitor 100 μ f/100V.

In a further embodiment, the DC/AC conversion module is configured to convert a direct current into an alternating current, and includes a PWM pulse width modulation converter U1, a timing resistor RT, 2 timing capacitors Ct, a field effect power amplifier switch Q2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a transistor Q1, a capacitor C7, an inductor L, a diode D3, a resistor Rs, a capacitor Css, and a resistor RD; the pin + ERR of the PWM converter U1 is connected with one end of a resistor R3, the other end of the resistor R3 is connected with one end of a resistor R1, one end of a resistor R2 and one end of a capacitor, the other end of the capacitor and the other end of a resistor R1 are connected with one end of a resistor R4, the other end of the resistor R4 is connected with the pin-ERR of the PWM converter U1 and a collector of a triode Q1, and the other end of the resistor R2 is connected with the pin Vref of the PWM converter U1; the pin Comp and the pin-ERR of the PWM converter U1 are connected through a capacitor; a pin Css of the PWM converter U1 is connected with one end of a capacitor Css, and the other end of the capacitor Css is connected with the negative electrode of a power supply; one end of the resistor R4 is connected with the negative pole of the power supply; a pin RD of the PWM converter U1 is connected with a power supply cathode through a resistor RD, a pin GND of the PWM converter U1 is connected with the power supply cathode, a pin RT of the PWM converter U1 is connected with the power supply cathode through a timing resistor RT, a pin Ct of the PWM converter U1 is sequentially connected with 2 timing capacitors Ct, the timing capacitors Ct are connected with pins + Vcc and + Vc of the PWM converter U1, capacitors and resistors R6 are connected between a pin-Cs and the pins + Cs of the PWM converter U1 in parallel, one end of the resistor R7 is connected with one end of the resistor R6, the other end of the resistor R8 is connected with one end of the field effect power amplifier Q2, and the other end of the resistor R8 is connected with the other end of the resistor R6; the grid of the field effect power amplifier switch tube Q2 is connected with one end of a resistor R9, the other end of the resistor R9 is connected with a pin OutA of a PWM (pulse-width modulation) converter U1, the drain of the field effect power amplifier switch tube Q2 is connected with one end of a resistor R10 and the anode of a diode D3 through a capacitor, the other end of the resistor R10 is connected with one end of a capacitor C7, the cathode of a diode D3 is connected with the other end of a capacitor C7 and one end of a resistor Rs, the other end of the resistor Rs is connected with one end of a resistor R5 and the emitter of a triode Q1, the other end of the resistor R5 and the base of the triode Q1 are connected with one end of a capacitor C7 as output ends, and the pin Vcc + of the PWM converter U1 is connected with one.

In some embodiments, the pulse width modulator is a core device of the seismic source exciter, and the relevant auxiliary circuits are connected by taking the pulse width modulator as a center.

The functions of the pin numbers of the pulse width modulator SG1526 are as follows:

1, pin: + ERROR, ERROR amplifier non-inverting input.

And (2) pin: ERROR, ERROR amplifier inverting input.

And 3, pin: comp compensation.

4, pin: the Css soft starts.

And 5, feet: reset resets (not, add line above).

6, pin: -a CS current limiting comparator, inverting input.

7, pin: + CS current-limited comparator, non-inverting input.

And 8, pins: SD is off (not, plus line above).

And (9) pin: rt, connected to the timing resistor.

And (5) a pin 10: ct, connected to the timing capacitor.

11, pin: rd, dead-zone time resistance.

12 feet: sync (not, top bar).

13 feet: OutputA, output a.

14, pins: + Vc.

15 feet: ground is connected to Ground.

16 feet: OutputB, output B.

17, pin: + Vcc.

18 feet: vref reference voltage.

Supply of non-inverting input error amplifier voltage: a voltage divider is formed by R1(2.49 Komega) and R2(2.49 Komega), the upper end of R2 is connected with the 18-pin reference voltage Vref of the PWM pulse width modulator SG1526, the lower end of R2 is connected with the upper end of R1, and the lower end of R1 is grounded, so that the voltage divider is formed. The node between the lower end of R2 and the upper end of R1 is connected to R3(15.4 K.OMEGA.), and the other end of R3 is connected to pin 1 of PWM pulse width modulator SG1526, so that the reference voltage of the voltage divider formed by R1 and R2 is applied to the + ERROR ERROR amplifier non-inverting input terminal of pin 1 of PWM pulse width modulator SG1526 through R3.

The inverting input of the 2-pin ERROR amplifier of the PWM pulse width modulator SG1526 is connected to the 3-pin Comp compensation terminal via a capacitor C2(200 pf).

Supply of the inverting input error amplifier voltage: the voltage feedback circuit and R4(16.9K omega) form a voltage divider, and the voltage feedback circuit is composed of Q1(2N2605) and R₅(57.6KΩ)、R⁵(392K Ω), C7(34 μ f/100V), D3(UES1102), R4 is grounded at its lower end, and R4 is connected at its upper end to the collector of Q1 in the voltage feedback circuit, so that the feedback voltage on the voltage divider formed by the voltage feedback circuit and R4 is applied to the inverting input of the 2-pin ERROR amplifier in PWM pulse width modulator SG 1526.

The stable working principle is maintained that when the output voltage is reduced, the feedback voltage is reduced, the voltage of the inverting input end of the-ERROR ERROR amplifier of the pin 2 on the PWM 1526 is reduced, and the voltage of the non-inverting input end of the + ERROR ERROR amplifier of the pin 1 on the PWM 1526 is fixed, so that △ U is obtained_1-2The error voltage value between the two is increased, so that the output duty ratio of the 13 pin and the 16 pin on the PWM pulse width modulator SG1526 is widened, the width of the output pulse is widened, the on-time is lengthened, and the output voltage is increased. Vice versa, when the output voltage increases, the feedback voltage increases, the voltage at the inverting input terminal of the 2-pin ERROR amplifier of the PWM pulse width modulator SG1526 increases, and the voltage at the non-inverting input terminal of the 1-pin ERROR amplifier of the PWM pulse width modulator SG1526 is constant, so that the output voltage increases△U_1-2The error voltage value between the two pins becomes smaller, so that the output duty ratio of the

pins

13 and 16 on the PWM pulse width modulator SG1526 becomes narrower, the output pulse width becomes narrower, the on-time becomes shorter, and the output voltage is reduced.

According to the above-mentioned principle of stable operation, when the voltage of the capacitor C7 reaches a certain value (e.g. 60V, corresponding to the voltage of the high-voltage capacitors C21 and C22 reaching 600V), the rising voltage of C7 is applied to the inverting input terminal of the 2-pin ERROR amplifier of the PWM pulse-width modulator SG1526 through the collector of Q1, so as to raise the voltage, while the voltage of the + ERROR amplifier inverting input terminal of the 1-pin of the PWM pulse-width modulator SG1526 is fixed, so that △ U is obtained_1-2The error voltage value between the two steps becomes smaller, so that the output duty ratio of a pin 13 on the PWM 1526 becomes narrow, the output pulse width becomes narrow, the conduction time becomes short, the output voltage is reduced, and the stable high voltage is maintained.

Soft start: and the lower end of the capacitor Css (0.1 muf) is grounded, and the upper end of the capacitor Css is connected with the 4 pin of the PWM 1526 pin, so that the voltage of the capacitor Css gradually rises from 0V to a normal value when the power supply is just switched on, and the impact on the power supply when the power supply is just switched on is reduced.

Resetting: the pin 5 of the PWM pulse width modulator SG1526 is Reset, and when the power switch is turned off, the Reset is performed.

The current-limiting protection circuit comprises a voltage divider formed by R6(100 omega) and R7(44.2 omega), the upper end of R6 is connected with the left end of R7 and is simultaneously connected with the 7 feet of PWM 1526, the non-inverting input end of + CS current-limiting comparator is connected with the ground, the lower end of R6 is connected with the 6 feet of PWM 1526, the inverting input end of CS current-limiting comparator, the right end of R7 is connected with the source electrode of Q2(IRF540) of a power amplifier switch tube, and is connected with the upper end of R8(0.25 omega/2W), the lower end of R8 is connected with the ground, when the source current of Q2 of the power amplifier switch tube increases to a certain set value, the voltage of the upper end of R8 increases, namely the voltage of R7 increases, then the voltage of the right end of the voltage divider formed by R6 and R7 increases, and the increased voltage is added to the 7 feet of PWM 6 through R7, but the PWM 1526 is unchanged, the voltage of SG △ is grounded, and the U64 is connected with the ground_6-7The voltage value between rises when △ U_6-7When the voltage between the two circuits rises to a certain set value, the current-limiting protection circuit acts to enable U₁₃The output pulse is narrowed, and the current limiting protection effect is achieved.

Turning off the circuit: the pin 8 of the PWM pulse width modulator SG1526 is off, and when the power switch is turned off, it is turned off.

Selection of operating frequency: the selection of the operating frequency depends on a timing resistor Rt connected to pin 9 of the PWM pulse width modulator SG1526 and a timing capacitor Ct connected to pin 10 of the PWM pulse width modulator SG 1526. The upper end of a timing resistor Rt (37.4K omega) is connected with a pin 9 of the PWM 1526, and the lower end of the Rt is grounded. The left end of a timing capacitor Ct (0.001 muf) is connected with a pin 10 of the PWM 1526, and the upper end of the Ct is connected with Vc. The operating frequency F is 1/1.1 × Ct × Rt. The proper working frequency is preferably selected to be 15-25 KHz by selecting proper timing resistance Rt (several-100K omega) and timing capacitance Ct (0.001-20 muf).

Dead time: the dead time resistor Rd is connected with the 11 pin of the PWM 1526, the larger the resistance of the Rd is, the longer the dead time is, and the reliability of the circuit is improved, but the efficiency is reduced; on the contrary, the smaller the resistance of the Rd is, the shorter the dead time is, which leads to the decrease of the reliability of the circuit, but the efficiency is improved, so that the proper dead time is selected to improve the efficiency on the premise of ensuring the reliable operation of the circuit. Because the circuit only uses one output end and only connects one power amplifier switch tube, the condition that two output ends are connected with the power amplifier switch tube and are simultaneously conducted to form a power supply short circuit does not exist, so that the 11 feet of the PWM 1526 are directly grounded, and the dead time is shortest.

Output circuit Output a: the Output of a 13-pin Output A of the PWM 1526 is connected to the grid of a Q2 field effect power amplifier switching tube through R9(10 omega), the left end of R9 is connected with the Output A of the 13-pin of the SG1526, the right end of R9 is connected with the grid of Q2, the drain of Q2 is connected with a 2-pin of a high-frequency pulse transformer T1, and the source of Q2 is connected with the junction of R7 and R8. The function of the Q2 field effect power amplifier switching tube is to control the switching time according to the width of the Output pulse of pin 13 Output a of the PWM pulse width modulator SG 1526. When the output duty ratio is widened, the width of the output pulse is widened, the conduction time is lengthened, and the output voltage is increased; when the output pulse width becomes narrower, the on time becomes shorter, causing the output voltage to decrease. In other words, the switching time is controlled to be longer or shorter according to the width of the output pulse of the PWM so as to maintain the high voltage constant. The output circuit only uses the output A and only uses one power amplifier switch tube, thus meeting the functional requirements of the subsequent circuit, simplifying the circuit design, saving the cost and improving the reliability due to the reduction of the using amount of components.

A power supply circuit: the negative terminal of the battery is connected with the 15 pin group of the PWM 1526 and is grounded, and the positive terminal of the battery is connected with the input end of the regulated voltage and is connected with the source of the Q3 and the negative terminal of the voltage-stabilizing diode D4. The output end of the voltage-stabilized source is connected with a pin 14 + Vc of the PWM 1526 and a pin 17 + Vcc of the PWM 1526, and is connected with the drain electrode of the Q3 and the positive end of the filter capacitor, and the voltage-stabilized source provides stable voltage for related circuits.

Vref reference voltage circuit: the 18-pin Vref reference voltage of the PWM 1526 is connected with the upper end of the resistor R2, provides a reference voltage for the voltage divider formed by R1 and R2, and provides the reference voltage for the non-inverting input end of the 1-pin + ERROR ERROR amplifier of the PWM 1526 through R3.

The main components of the PWM converter circuit are selected as follows:

the pulse width modulator is a core device of the seismic source exciter, the pulse width modulator SG1526 (temperature range is from minus 55 ℃ to plus 125 ℃), SG2526 (temperature range is from minus 25 ℃ to plus 85 ℃), and SG3526 (temperature range is from 0 ℃ to plus 70 ℃) are selected, and the seismic source exciter is used in the field environment, is possibly used in the high-temperature environment of the desert region in summer and the low-temperature environment of the alpine region in winter, so the SG1526 with the temperature range from minus 55 ℃ to plus 125 ℃ is preferentially selected to ensure the high stability and the high reliability of the seismic source exciter.

Secondly, the power amplifier switch tube is a high-power device of the vibration source exciter, and in order to reduce power consumption, an N-channel enhanced insulated gate MOSFET field effect power amplifier switch tube IRF540 (main parameter: 100V/28A/150W) is preferably selected, and an IRF530 (main parameter: 100V/14A/79W) can be selected.

③ 2N2605(PNP silicon triode, 60V, 0.03A, beta: 150-200).

And fourthly, the resistor used as the voltage divider selects a precision resistor, and the timing capacitor Ct and the timing resistor Rt all select components with constant temperature coefficient so as to ensure the stability of the working frequency of the PWM.

As described above, the PWM converter operates to convert the dc power supplied from the battery into the high-frequency ac power and output the high-frequency ac power to the subsequent booster circuit.

In a further embodiment, the alternating current boosting module is used for boosting low-voltage high-frequency alternating current into high-voltage high-frequency alternating current and mainly comprises a high-frequency pulse transformer T1.

The high-frequency alternating current output by the DC/AC conversion module is connected to a primary coil at the input end of a high-frequency pulse transformer T1, namely a pin 2 of the primary coil of a high-frequency pulse transformer T1 is connected with the drain electrode of a power amplifier switch tube Q2, a pin 1 of the primary coil of a high-frequency pulse transformer T1 is connected with the positive output end of a voltage stabilizing circuit through an inductor L1, and the output of the pulse width modulator works in a high-current switching state with large load change, so that the output voltage change is small by using an inductance filter L1, and the external characteristic is hard. The ac boosting module boosts the high-frequency ac power output from the pulse width modulator via the high-frequency pulse transformer T1, and boosts the high-frequency ac power to a high-voltage at the secondary side of the high-frequency pulse transformer T1.

Selecting a high-frequency pulse transformer: because the working frequency is higher, a high-frequency pulse transformer is selected. The working frequency of the circuit is about 15-25 KHz, and a high-frequency pulse transformer with the efficiency higher than 95% is selected.

In a further embodiment, the high-voltage rectifying circuit is used for rectifying high-frequency high-voltage alternating current into high-voltage direct current and storing the high-voltage direct current, so as to provide sufficient energy for high-voltage detonation, and the high-voltage rectifying circuit includes: rectifier diodes D1(1N4937), rectifier diodes D2(1N 4937); a resistor R11(100K omega/1W), a resistor R12(100K omega/1W), a high-voltage energy storage capacitor C21(100 muf/400V) and an energy storage capacitor C22(100 muf/400V). The positive end of the rectifying diode D1 is connected with the 3 pin of the secondary coil of the high-frequency pulse transformer T1, the negative end of the rectifying diode D1 is connected with the positive end of the high-voltage energy storage capacitor C21 and one end of the resistor R11, the negative end of the rectifying diode D2 is connected with the 5 pin of the secondary coil of the high-frequency pulse transformer T1, the positive end of the rectifying diode D2 is connected with the negative end of the high-voltage energy storage capacitor C22 and one end of the resistor R12, the other end of the resistor R11 is connected with the other end of the resistor R12 and is simultaneously connected with the connecting point of the 4 pin of the center tap of the secondary coil of the high-frequency pulse transformer T1 and the negative end of the high-voltage energy storage capacitor C21 and the. The negative terminal of the high-voltage energy-storing capacitor C21 is connected with the positive terminal of C22, i.e. the high-voltage energy-storing capacitor C21 is connected with the high-voltage energy-storing capacitor C22 in series, and is also connected with the center-tapped 4-pin of the secondary coil of the high-frequency pulse transformer T1.

The high-voltage rectifier circuit in this embodiment is a center-tapped full-wave rectifier circuit, and is actually formed by combining two half-wave rectifier circuits, and the flow direction of current is: a pin 3 of a secondary coil of the high-frequency pulse transformer T1 → a rectifier diode D1 → an energy storage capacitor C21 → a pin 4 of a center tap of the secondary coil of the high-frequency pulse transformer T1; ② 4 feet of the center tap of the secondary coil of the high-frequency pulse transformer T1 → C22 → rectifier diode D2 → 5 feet of the secondary coil of the high-frequency pulse transformer T1. Because C21 and C22 are connected in series, the total voltage is the sum of the voltage sums across C21 and C22, and the high voltage rectifying and energy storage circuit provides sufficient charge energy for high voltage detonation.

To monitor whether the high voltage is normal, a DC voltmeter or a neon bulb display can be connected between the positive terminal of C21 and the negative terminal of C22 to visually monitor the high voltage condition on the energy storage capacitor. The neon bulb circuits for high voltage are shown in fig. 6, R26(3M Ω), R27(1.3M Ω), and C (10 μ f).

Specifically, the high-voltage rectifier circuit component is selected from:

the high-frequency fast recovery FRD high-frequency rectifier diode FRD1N4937 (the forward average working current 1A, the reverse repeated peak voltage 600V and the reverse recovery time TRR150nS) with good switching characteristics is selected because the voltage is high and the high-frequency fast recovery FRD high-frequency rectifier diode works at a high frequency.

Secondly, the energy storage capacitor is a high-quality capacitor with enough capacity, enough high withstand voltage, as little electric leakage as possible and stable temperature coefficient.

In a further embodiment, the GPS or Beidou module is used for providing accurate GPS or Beidou reference time pulse, and as the excitation of the detonator explosive source is carried out in the field, GPS or Beidou satellite signals can be received.

After the received GPS or Beidou reference time pulse signals are subjected to frequency division by a frequency division driving circuit, time interval pulse signals of 10S, 20S, 30S and 60S (selected according to the actual field work requirement) are respectively taken, and then are driven by TTL level, a silicon controlled electronic switch in a high-voltage detonating circuit is started to be switched on, the charges of an energy storage capacitor are quickly released to detonate detonator explosives, and the seismic source is excited in accurate time.

The frequency dividing circuit device may be selected as appropriate, such as: SN54/7490 can be divided into two, five and ten minutes; SN54/7492 can be divided into two, three, six and twelve; SN54/7493 can be divided into two, four, eight, and sixteen minutes.

The frequency dividing circuit is composed of a trigger, a TTL device such as SN7496 can be selected, and a TTL device such as driver SN74HC14 can be selected as the driving circuit.

As shown in fig. 5, in a further embodiment, the function of the initiation circuit is to detonate detonator explosives under the control of accurate GPS or Beidou reference time to complete seismic source excitation, and specifically includes: the circuit comprises an NPN triode Q4, a pulse transformer T2, a silicon controlled rectifier Q5(2N6509), a resistor R21, a diode D5, a resistor R22, a resistor R23, a resistor R24 and a resistor R25. The base electrode of the triode Q4 is connected with the pulse signal output end after GPS or Beidou reference time is subjected to frequency division and driving through a resistor R21(680 omega), the emitter electrode of the triode Q4 is grounded, the collector electrode of the triode Q4 is connected with the 2 pin of the primary coil of the pulse transformer T2 and is simultaneously connected with the positive end of a protective diode D5(1N914B), and the 3 pin of the primary coil of the T2 is connected with the negative end of the diode D5 and is connected with Vcc.

The diode D5 connected in parallel with the primary winding of the pulse transformer T2 plays a role in protecting the transistor Q4 from being broken down by overvoltage, and its principle is: when the transistor Q4 is turned off, the sharp drop of the collector current will make the two ends of the primary coil of the pulse transformer T2 generate high back electromotive force, which is added to the collector of the transistor Q4 after being superimposed with the power supply voltage Vcc, so that the voltage difference between the collector and the emitter of the transistor Q4 is increased, and the transistor Q4 is easy to break down. The protection diode D5 provides a discharge path for the back emf, thereby preventing the transistor Q4 from breakdown.

The 3 feet of the secondary coil of the pulse transformer T2 are connected with the negative end of the energy storage capacitor C22. The resistor R22(30 omega) and the resistor R23(100 omega) form a voltage divider, the resistor R23 is connected with the capacitor in parallel, and one end of the resistor R23 is connected with the negative end of the energy storage capacitor C22 and the pin 3 of the secondary coil of the pulse transformer T2. One end of the resistor R22 is connected with the 4 feet of the secondary coil of the pulse transformer T2, and the other end of the resistor R22 is connected with one end of the resistor R23 and one end of the capacitor C23(0.1 muf/50V) and is connected with the control electrode of the thyristor Q5(2N 6509). The anode of the thyristor Q5 is connected with the positive end of the energy storage capacitor C21 through a resistor R24(30 omega/3W), and the cathode of the thyristor Q5 is connected with the negative end of the energy storage capacitor C22.

The working principle of the high-voltage detonating circuit is as follows: when the leading edge of the divided and driven time reference signal pulse arrives, Q4 is turned on, the primary coil of the pulse transformer T2 generates a signal current, and the secondary coil of T2 subsequently generates an induced pulse, which is applied to the control electrode of the thyristor Q5 serving as an electronic switch through the voltage divider formed by R22 and R23 via R22, so that the electronic switch Q5 is turned on and the current is discharged from the positive terminal of the energy storage capacitor to the detonator through the turned-on electronic switch thyristor Q5. The discharge path is: the positive end of the energy storage capacitor C21 → the conducted thyristor Q5 → the detonator → the negative end of the energy storage capacitor C22. Because the voltage of the energy storage capacitor is high (generally 600), the capacity is large (generally 50 muf), and the energy is large, the instantaneous current flowing through the detonator is very large, the detonator is instantaneously detonated, the explosive is detonated, and the accurate excitation of the seismic source on the set GPS or Beidou reference time is completed. After the excitation is finished, the mode switch automatically resets.

Selection of components of the high-voltage detonation circuit:

controlled silicon 2N 6509: forward withstand voltage VDRM, 800V; reverse withstand voltage VRRM, 800V; forward average current IF, 25A; the gate trigger current IGT is less than 30 mA; and the on-state pressure drop VTM is 1.8V.

② triode 2N 2222: NPN type, 60V; 600 mA; hfe100 to 300.

Diode 1N 914B: reverse voltage 75V, forward current 300mA, recovery time 4 nS.

Function switch: the function is to connect relevant functional gears and select a multi-pole multi-throw wave band switch with an automatic reset function. The switch is divided into two stages of working (on) and resetting (off), controls the on and off of the power supply, and changes the connection mode of the detonator terminal. When the detonator is in a working (on) state, the power supply is connected, all circuits work, the detonator terminal is connected with the high-voltage circuit through the switch, and seismic source excitation for detonating detonator explosives is completed at GPS or Beidou precise time. The high-voltage electric detonator is in a reset (off) state in non-working time, the power supply is off, other circuits are not in operation except the GPS or Beidou continuous power supply, the detonator terminal is in short circuit through the switch, and the high-voltage capacitor discharges residual charges through the switch and R25(30 omega/3W) so as to ensure safety.

The invention is specially innovated for adapting to node type seismic data acquisition which is increasingly widely used, a plurality of seismic source exciters can be arranged at the same time, each seismic source exciter works independently, actually, the seismic source exciters are in a parallel working relation, and a plurality of seismic source exciters can work in a staggered time as long as each excitation point is arranged in a plan before the detonation, so that the time is greatly saved, and the field operation construction efficiency is improved.

Claims

1. The seismic source exciter is characterized by comprising a power supply module, a voltage stabilizing circuit, a DC/AC conversion module, an alternating current boosting module, a high-voltage rectifying circuit, a GPS or Beidou module, a frequency division driving circuit and an initiation circuit, wherein the power supply module, the voltage stabilizing circuit, the DC/AC conversion module, the alternating current boosting module, the high-voltage rectifying circuit and the initiation circuit are sequentially connected, and the frequency division driving circuit is connected with the GPS or Beidou module and used for outputting time reference frequency division driving signals to the high-voltage initiation circuit.

2. The seismic source exciter of claim 1, wherein the DC/AC conversion module is configured to convert DC power to AC power, and comprises a PWM converter U1, a timing resistor RT, 2 timing capacitors Ct, a field effect power amplifier switch Q2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a transistor Q1, a capacitor C7, an inductor L, a diode D3, a resistor Rs, a capacitor Css, and a resistor RD; the pin + ERR of the PWM converter U1 is connected with one end of a resistor R3, the other end of the resistor R3 is connected with one end of a resistor R1, one end of a resistor R2 and one end of a capacitor, the other end of the capacitor and the other end of a resistor R1 are connected with one end of a resistor R4, the other end of the resistor R4 is connected with the pin-ERR of the PWM converter U1 and a collector of a triode Q1, and the other end of the resistor R2 is connected with the pin Vref of the PWM converter U1; the pin Comp and the pin-ERR of the PWM converter U1 are connected through a capacitor; a pin Css of the PWM converter U1 is connected with one end of a capacitor Css, and the other end of the capacitor Css is connected with the negative electrode of a power supply; one end of the resistor R4 is connected with the negative pole of the power supply; a pin RD of the PWM converter U1 is connected with a power supply cathode through a resistor RD, a pin GND of the PWM converter U1 is connected with the power supply cathode, a pin RT of the PWM converter U1 is connected with the power supply cathode through a timing resistor RT, a pin Ct of the PWM converter U1 is sequentially connected with 2 timing capacitors Ct, the timing capacitors Ct are connected with pins + Vcc and + Vc of the PWM converter U1, capacitors and resistors R6 are connected between a pin-Cs and the pins + Cs of the PWM converter U1 in parallel, one end of the resistor R7 is connected with one end of the resistor R6, the other end of the resistor R8 is connected with one end of the field effect power amplifier Q2, and the other end of the resistor R8 is connected with the other end of the resistor R6; the grid of the field effect power amplifier switch tube Q2 is connected with one end of a resistor R9, the other end of the resistor R9 is connected with a pin OutA of a PWM (pulse-width modulation) converter U1, the drain of the field effect power amplifier switch tube Q2 is connected with one end of a resistor R10 and the anode of a diode D3 through a capacitor, the other end of the resistor R10 is connected with one end of a capacitor C7, the cathode of a diode D3 is connected with the other end of a capacitor C7 and one end of a resistor Rs, the other end of the resistor Rs is connected with one end of a resistor R5 and the emitter of a triode Q1, the other end of the resistor R5 and the base of the triode Q1 are connected with one end of a capacitor C7 as output ends, and the pin Vcc + of the PWM converter U1 is connected with one.

3. The source exciter of claim 1, wherein the ac boost module comprises a high frequency pulse transformer T1, the high frequency pulse transformer T1 operating at a frequency of 15KHz to 25 KHz.

4. The source exciter of claim 1, wherein the high voltage rectifier circuit comprises a rectifier diode D1, a rectifier diode D2, a resistor R11, a resistor R12, an energy storage capacitor C21, and an energy storage capacitor C22, the positive end of the rectifying diode D1 is connected with one end of the secondary coil of the high-frequency pulse transformer T1, the negative end of the rectifying diode D1 is connected with the positive end of the energy storage capacitor C21 and one end of the resistor R11, the negative end of the rectifying diode D2 is connected with the other end of the secondary coil of the high-frequency pulse transformer T1, the positive end of the rectifying diode D2 is connected with the negative end of the high-voltage energy storage capacitor C22 and one end of the resistor R12, the other end of the resistor R11 is connected with the other end of the resistor R12, and is connected to the center tap of the secondary coil of the high-frequency pulse transformer T1 and the connection point of the negative terminal of the high-voltage energy-storing capacitor C21 and the positive terminal of the high-voltage energy-storing capacitor C22.

5. The seismic source exciter of claim 1, wherein the initiation circuit comprises a transistor Q4, a pulse transformer T2, a thyristor Q5, a resistor R21, a diode D5, a resistor R22, a resistor R23, a resistor R24 and a resistor R25, wherein a base of the transistor Q4 is connected to an output end of the frequency-dividing driving circuit through a resistor R21, an emitter of the transistor Q4 is grounded, a collector of the transistor Q4 is connected to one end of a primary coil of the pulse transformer T2 and a positive end of the diode D5, the other end of the primary coil of the pulse transformer T2 is connected to a negative end of the diode D5 and to a positive power supply electrode, a resistor R22 and a resistor R23 form a voltage divider, the resistor R23 is connected in parallel with a capacitor, one end of the resistor R23 is connected to a negative end of an energy storage capacitor C22 and one end of a secondary coil of the pulse transformer T2, one end of the resistor R22 is connected to the other end of the secondary, the other end of the resistor R22 is connected with one end of the resistor R23 and one end of the capacitor and is connected with the control electrode of the controlled silicon Q5, the anode of the controlled silicon Q5 is connected with one output end of the high-voltage rectifying circuit through the resistor R24, and the cathode of the controlled silicon Q5 is connected with the other output end of the high-voltage rectifying circuit.