CN113866835A - Electromagnetic emission system with time domain three-waveform combination and control method - Google Patents
Electromagnetic emission system with time domain three-waveform combination and control method Download PDFInfo
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Abstract
The invention relates to a time domain three-waveform combined electromagnetic emission system and a control method, aiming at generating trapezoidal waves and triangular waves with different turn-off time, half sine waves with different pulse widths and combined waveform emission current thereof. The transmitting system consists of a main control circuit, a transmitting bridge circuit, an RLC series resonance circuit, a passive clamping circuit, a transmitting coil and the like. Setting emission parameters according to exploration requirements, and outputting PWM signals by a main control circuit to drive corresponding switch modules in an emission system through an optocoupler; when the transmitting bridge circuit is switched on, the passive clamp circuit provides different clamp voltages for the transmitting coil during the trapezoidal wave or triangular wave switching-off period to realize controllable current switching-off time; when the RLC series resonant circuit is switched on, the energy storage capacitor supplies power to the resonant circuit to generate a bipolar half sine wave. The electromagnetic emission system with the time domain three-waveform combination is applied to SQUID-based induction-polarization double-field detection, so that the problems of shallow detection blind areas and SQUID lock loss can be solved, and the overall exploration precision of the transient electromagnetic method is improved.
Description
Technical Field
The invention relates to an electromagnetic emission system with a time domain three-waveform combination and a control method, which are suitable for the field of geophysical exploration or geological structure detection by an electromagnetic method, and particularly provide an excitation source for a magnetic source time domain electromagnetic detection method.
Background
A magnetic source time domain electromagnetic detection method utilizes an ungrounded return line to emit bipolar pulse current to the underground, wherein the pulse current can be square wave, trapezoidal wave, triangular wave, half sine wave and the like, and in the intermittent process of a primary field generated by emitting pulses, signals of secondary fields changing along with time are collected through a receiving coil or a Superconducting Quantum Interference Device (SQUID) and a receiver, and data are processed and interpreted to obtain abundant resistivity or polarizability information of underground media. The transient electromagnetic method has the advantages of large detection depth, economy and convenience, and is widely applied to geological resource exploration and engineering detection.
In the traditional time domain electromagnetic method, because the limit of a detecting instrument and a data interpretation method is only used for exciting and interpreting electromagnetic induction signals, the measurement parameters and the interpretation parameters are single, the accuracy of data interpretation is low, and the accuracy of exploration results is low; because the transmitting coil is an inductive load and contains larger parasitic inductance, the current cannot be reduced to zero immediately after the transmitting current is switched off, but is in e-exponential attenuation, overshoot and oscillation phenomena can occur at the tail part of the current, the waveform quality of the transmitting current is lower due to the reasons, shallow information is seriously lost, and the primary field cannot be offset and corrected during data interpretation; the low performance of a transmitting system and the single interpretation parameter seriously limit the further development and application of the transient electromagnetic method.
In order to meet the requirement of simultaneous detection of a deep layer and a shallow layer, the traditional bipolar trapezoidal wave is not applicable any more, the high-frequency components of the bipolar triangular wave are rich, the pulse width is small, the propagation distance of electromagnetic wave is small, and the signals obtained by a receiving system are mainly the signals of a shallow geologic body; the pulse width of the half sine wave emission current is large, the low-frequency components are rich, and the half sine wave emission current can be used as an excitation source for deep geologic body detection; the triangular wave and the half sine wave are combined to emit current, so that geologic bodies at different depths can be detected, and the detection blind area of an electromagnetic method is reduced.
In recent years, with the progress of instruments and the development of electromagnetic theory, researchers carry out deep research on the induced polarization effect, and meanwhile, the interpretation precision of the ground can be effectively improved by detecting an induction field and an induced polarization signal. The induction field (TEM) is a secondary induction magnetic field generated by the underground medium, and the induction field is explained to obtain the conductivity parameter of the underground medium; the polarization field (IP) is an induced polarization field generated by excitation after the earth is electrified, and the polarization field is interpreted to obtain a polarizability parameter of the underground medium. Researches show that both TEM and IP can detect water resources and metal ores, and an induction field and a polarization field are found to exist simultaneously in the low-frequency time domain electromagnetic detection process; after the current is cut off, the early induction field is quickly attenuated, and the induction field and the polarization field coexist, mainly serve as the induction field, and the polarization field serves as the polarization field at the later stage. The polarization charging effect exists during the turn-off period of the emission current of the magnetic source, when the amplitude of the emission current is constant, the turn-off time is shorter, and the polarization charging time is shorter, so that the induced polarization field is weaker, and the method is suitable for induction field measurement; the longer the turn-off time is, the longer the polarization charging time is, resulting in a stronger induced polarization field, which is suitable for polarization field measurement. Therefore, the combined emission current of the trapezoidal wave and the triangular wave which emit various different turn-off times can be used for simultaneously detecting IP and TEM signals.
The Superconducting Quantum Interference Device (SQUID) has the characteristics of low noise, large bandwidth and high sensitivity (fT magnitude), and is successfully applied to transient electromagnetism. However, the SQUID sensor needs to work in a low electromagnetic noise environment, and the system slew rate (2.4mT/s) is also small, which puts new requirements on the emission system. The emission current overshoot and the tail oscillation can generate large electromagnetic interference, which may cause the locking loss of the SQUID system and the normal operation failure, so that an absorption circuit needs to be connected in the emission current turn-off process to inhibit the current overshoot and the tail oscillation. When the current changes too fast in the rising process or the falling process of the emission current, the SQUID system loses lock due to exceeding the slew rate, although the low-voltage clamping circuit can prolong the turn-off time of the emission current, the effect is still limited, and the clamping circuit cannot change the rising process of the emission current, so that the SQUID system is unstable in work, and the phenomenon of losing lock still occurs. Therefore, an RLC series resonance circuit is added in the transmitting system, the generated bipolar half sine wave transmitting current is large in pulse width, the rising part and the falling part of the waveform are symmetrical, the overall transmitting current changes slowly, the requirements of the SQUID system can be completely met, the SQUID system can be prevented from losing lock, and the SQUID can work stably. In order to be combined with the advantage of trapezoidal wave linear turn-off, the emission current of the combination of the trapezoidal wave and the half sine wave is used as an excitation source for SQUID system detection, so that the stability and the precision of the detection system can be obviously improved.
Chinese patent CN107017610B discloses a passive constant voltage clamp fast turn-off circuit of a transient electromagnetic transmitter, wherein TVS tubes are connected in series at two ends of a transmitting coil through an electronic switch to provide passive clamp voltage for the coil; in addition, a variable damping matching absorption circuit is adopted to absorb the electric energy of the coil reverse discharge. The clamping voltage adjustable circuit and the absorption circuit are matched to realize the quick turn-off of the emission current.
Chinese patent CN108227011A discloses a dual trapezoidal wave emitting system with controllable falling edge and a control method thereof, wherein a switch module is connected in series with a group of high voltage transient suppression diodes or a group of low voltage transient suppression diodes during the turn-off period of the emitting current to form a high voltage clamp or a low voltage clamp, a group of trapezoidal wave emitting currents with different turn-off times are generated, the simultaneous detection of resistivity and polarizability dual parameters is realized, and the experimental result proves the effectiveness of the clamp voltage in changing the turn-off time of the emitting current.
The method discloses a method for enabling the current in the transmitting coil to be rapidly turned off or slowly turned off by the passive clamping circuit, and influences are exerted on the turn-off time of the trapezoidal wave transmitting current. However, for transient electromagnetic method shallow layer detection and SQUID sensor-based induction-polarization field dual-field measurement, the existing transmitting system can hardly meet the requirements; most transmitters can only transmit trapezoidal wave transmitting current, and the transmitting current has a single waveform, so that a transmitting system is difficult to excite a high-quality secondary field when facing a complex geological condition. How to transmit combined waveform and transmitting current with high waveform quality in time domain electromagnetic detection, reduce detection blind areas and realize induction-polarization field double-field accurate measurement is a technical problem which is urgently solved by technical personnel in the field.
Disclosure of Invention
The invention provides an electromagnetic emission system with a time domain three-waveform combination and a control method, and aims to solve the problems of single emission current waveform, limited shallow detection and loss of lock of a double field of an induction-polarization field measured based on a SQUID sensor.
The embodiment of the invention provides an electromagnetic transmitting system with a time domain three-waveform combination and a control method thereof, wherein the electromagnetic transmitting system comprises an external power supply, a main control circuit, a transmitting bridge circuit, a passive clamping circuit, an absorption circuit and an RLC series resonant circuit; the external power supply supplies power to the transmitting bridge circuit and also charges the energy storage capacitor; the main control circuit is used as a control part of the transmitting system and controls the switch module to work so as to generate different types of transmitting current waveforms; the transmitting bridge circuit is an H bridge circuit formed by four switch modules and provides bipolar trapezoidal wave or triangular wave transmitting current for the transmitting coil; the passive clamping circuit is composed of five groups of switch modules and four groups of transient suppression diodes (TVS), wherein one group of transient suppression diodes are connected in series at two ends of the transmitting coil during the period of transmitting current turn-off to provide a clamping voltage for the transmitting coil; the absorption circuit consists of a group of switch modules and a power resistor and is used for absorbing electric energy of emission current reverse discharge and inhibiting oscillation of the tail part of the current; the RLC series resonance circuit is composed of a transmitting coil, a nonpolar capacitor and an inductor, and generates bipolar half sine wave transmitting current under the action of an energy storage capacitor and a switch module.
Furthermore, the main control circuit outputs multiple paths of PWM waves according to the set emission parameters and drives corresponding switch modules in the emission system through the optocoupler, so that the emission system can be controlled to independently output trapezoidal wave or triangular wave emission current with controllable turn-off time and half sine wave emission current with different pulse widths; the emission current of the combination of the trapezoidal wave and the triangular wave, the combination of the trapezoidal wave and the half sine wave and the combination of the triangular wave and the half sine wave can also be output.
Furthermore, the transmitting bridge circuit is switched on and off by PWM waves output by the main control circuit through four switch modules of the optical coupling driving bridge circuit, and when the pulse width of the PWM waves is larger than the inherent rise time between a power supply and a transmitting coil, trapezoidal wave transmitting current with adjustable duty ratio and period can be generated; when the pulse width of the PWM wave is smaller than the inherent rise time, triangular wave emission current with adjustable pulse width and period can be generated.
Further, the switch modules in the transmitting bridge circuit, the clamping circuit, the absorption circuit and the RLC series resonant circuit are usually selected from IGBT modules, MOSFET modules or other types of switch modules with high voltage and current endurance to meet the requirement of high-power transmission.
Further, the passive clamping circuit is composed of a group of main switch modules, four component switch modules and four groups of transient suppression diodes; the main switch module is controlled by a signal generated by a NOR gate logic circuit, so that the main switch module is closed during the transmitting period and is opened during the transmitting current off period; each group of transient suppression diodes is formed by connecting a plurality of transient suppression diodes with the same voltage value in parallel, the clamping voltages of the four groups of transient suppression diodes are distributed from low voltage to high voltage, the selectable range of the clamping voltages is generally 8.5V to 120V, the group of transient suppression diodes are controlled by the main control circuit to be connected in series at two ends of the transmitting coil during the period of transmitting current turn-off, and the turn-off time of the transmitting current is controlled according to different clamping voltages.
Furthermore, the absorption circuit consists of a group of switch modules and a power resistor; the power resistor is controlled by the main control circuit to be connected in series at two ends of the transmitting coil during the period of transmitting current turn-off, and the resistance value of the power resistor is generally 200 times to 500 times of that of the transmitting coil; when a group of transient suppression diodes are connected during the turn-off of the transmitting current, the current in the transmitting coil firstly breaks down the transient suppression diodes to form a loop, and when the energy in the transmitting coil is not enough to maintain the breakdown state of the transient suppression diodes, the power resistor is connected to form a loop with the transmitting coil, so that the power resistor is used for absorbing the residual energy in the transmitting coil and suppressing the overshoot and tail oscillation of the transmitting current; during the turn-off period of the transmitting current, when the transient suppression diode is not connected, the power resistor and the transmitting coil form a loop, the energy in the transmitting coil can be absorbed quickly, and the turn-off time of the transmitting current is reduced.
Furthermore, the RLC series resonance circuit is composed of a transmitting coil, a non-polar capacitor and a magnetic ring inductor, wherein a resistor in the transmitting coil and a resistor in the inductor are used as resistors of the resonance circuit, the inductor in the transmitting coil and the magnetic ring inductor are used as inductors of the resonance circuit, and a plurality of high-voltage-resistance non-polar capacitors connected in parallel are used as capacitors of the resonance circuit; an external power supply charges a polar energy storage capacitor, the on-off of the switch module is controlled by the main control circuit, and the two energy storage capacitors respectively supply power to the RLC series resonance circuit to generate bipolar half sine wave emission current; the inductance and capacitance in the RLC series resonant circuit determine the pulse width of the half sine wave transmit current.
Compared with the prior art, the technical scheme provided by the embodiment of the invention has the following beneficial effects: the transmitting bridge circuit can transmit bipolar triangular waves or trapezoidal waves under the control of the main control circuit, transient suppression diodes with different clamping voltages are connected in series at two ends of the transmitting coil during the switching-off period of transmitting current, the switching-off time of the transmitting current is controllable, overshoot and tail oscillation of the transmitting current are suppressed through the access of the absorption circuit, and the waveform quality of the transmitting current is improved. By adopting the RLC series resonance circuit to transmit bipolar half sine wave transmitting current, the slow change of the transmitting current is realized, and the unlocking of the SQUID sensor is inhibited. The combination of the half sine wave and the triangular wave emission current realizes the simultaneous detection of geologic bodies at different depths; triangular waves and trapezoidal waves with different turn-off times are combined to emit current to realize the simultaneous measurement of induction-polarization fields; the combination of the trapezoidal wave and the half sine wave emits current to realize high-precision detection based on the SQUID sensor; the detection blind area of the time domain electromagnetic method is reduced, and the working efficiency is improved.
Drawings
FIG. 1 is a circuit diagram of a high power transient electromagnetic multi-waveform transmitting system and control method of the present invention;
FIG. 2 is an overall block diagram of the transient electromagnetic multi-waveform transmitting system of the present invention;
FIG. 3 is a circuit diagram of triangular and trapezoidal wave transmitting circuits with controllable turn-off time based on a transmitting bridge;
FIG. 4 is a diagram of a half sine wave transmit circuit based on an RLC series resonant circuit;
FIG. 5 is a graph of trapezoidal wave emission current waveform and clamp voltage at different turn-off times;
FIG. 6 is a triangular wave emission current waveform diagram for different turn-off times;
FIG. 7 is a graph of half sine wave transmit current waveforms of different amplitude and pulse width;
FIG. 8 is a graph of three combined emission current waveforms;
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Examples
Referring to fig. 1 and fig. 2, the time domain three waveform combined electromagnetic transmitting system provided by the invention mainly comprises a main control circuit, a key part, a liquid crystal display screen, a low-power supply, an optocoupler drive, a transmitting bridge circuit, a passive clamp circuit, an absorption circuit, an RLC series resonant circuit, a transient suppression diode, a power resistor, an energy storage capacitor, a transmitting coil, a high-power supply and a series of switch modules. Wherein the low-power supply supplies power for the main control circuit; the key part and the liquid crystal display screen are used as a man-machine interaction part and used for selecting and determining emission parameters; the optocoupler driving part boosts and increases the current of the PWM wave output by the main control circuit and is used for controlling the on-off of the switch module; the high-power supply provides energy for the transmitting coil and the energy storage capacitor; the transmitting bridge circuit consists of four switch modules and is used for generating bipolar triangular wave or trapezoidal wave transmitting current on the transmitting coil; the passive clamp circuit and the transient suppression diode are connected in series at two ends of the transmitting coil, and different clamp voltages are applied to the transmitting coil to change the turn-off time of transmitting current; the absorption circuit and the power resistor are connected in series at two ends of the transmitting coil and can be used for quickly switching off the transmitting current and inhibiting current overshoot and tail oscillation; the RLC series resonance circuit and the energy storage capacitor are used for generating bipolar half sine wave transmitting current on the transmitting coil.
The transmitting bridge circuit is an H bridge circuit formed by switch modules Q1, Q2, Q3 and Q4, the four switch modules are respectively positioned on an upper bridge arm and a lower bridge arm of the H bridge circuit, a transmitting coil is connected between the upper bridge arm and the lower bridge arm, and the transmitting coil is equivalent to a resistor r and an inductor L1; the switch modules Q1, Q2, Q3 and Q4 are switched on and off according to a certain period and pulse width under the control of the main control circuit, and when the pulse width is smaller than the inherent rise time between the power supply and the transmitting coil, the transmitting coil can generate bipolar triangular wave transmitting current; when the pulse width is larger than the inherent rise time between the power supply and the transmitting coil, the transmitting coil can generate bipolar trapezoidal wave transmitting current; in order to meet the requirement of high-power emission, the switch modules Q1, Q2, Q3 and Q4 are high-voltage-withstanding high-current-withstanding IGBTs, MOSFETs or other types of switches.
The passive clamp circuit consists of a group of total switches Q7 and Q8 and four groups of four-component switches Q9, Q10, Q11, Q12, Q13, Q14, Q15 and Q16 and four groups of transient suppression diodes TVS1, TVS2, TVS3 and TVS 4; the main switches Q7 and Q8 are controlled by logic signals generated by a NOR gate to be switched on and off, are opened when the emission current starts to be switched off, and are closed when the emission current starts to rise; the four-component switch is controlled by the master control circuit to be switched on and off, and one of the four-component switch is selected to be switched on all the time or the four switches are switched off; the clamping voltages of the TVS1, the TVS2, the TVS3 and the TVS4 are distributed from low to high, and each group of transient suppression diodes is formed by connecting a plurality of TVSs with the same clamping voltage in parallel; when a group of branch switches is turned on, a group of transient suppression diodes are connected in series at two ends of a transmitting coil during the period of transmitting current turn-off, clamping voltage is generated, and the turn-off time of transmitting current is changed.
The absorption circuit consists of a group of switches Q5, Q6 and a power resistor R, wherein the switches Q5 and Q6 are controlled by a master control circuit to be switched on and off, and are switched on when the emission current is switched off and switched off when the emission current starts to rise; when a set of TVS is accessed, the current in the transmitting coil breaks down the TVS tube and forms a loop with the TVS, at the moment, the power resistor is equivalent to an open circuit state, and when the transmitting current is reduced to a breakdown state incapable of maintaining the TVS, the transmitting coil and the power resistor form a loop to release residual energy; when no TVS is accessed during the turn-off period of the transmitting current, the transmitting coil directly forms a loop with the power resistor, and the current in the transmitting coil can be rapidly turned off because the resistance value of the power resistor is far greater than that of the transmitting coil.
The RLC series resonance circuit consists of energy storage capacitors C1 and C2, circuit change-over switches Q17, Q18 and Q19, resonance control switches Q1 and Q2, current flow control diodes D1 and D2, a non-polar capacitor C3, a magnetic loop inductor L2 and a transmitting coil; after the energy of the power supply is obtained by the energy storage capacitors C1 and C2, the resonant circuit is powered; the circuit switching switches Q17, Q18 and Q19 are controlled by the main control circuit to be switched on and off, when Q17, Q18 and Q19 are kept in an open state, the transmitting system transmits bipolar half sine waves, and when Q17, Q18 and Q19 are kept in an open state, the transmitting system transmits bipolar triangular waves or trapezoidal waves; the resonance control switches Q1 and Q2 are controlled by the main control circuit to be switched on and off, so that the energy storage capacitor and the resonance circuit are controlled to be switched on and off, and the polarity of half sine wave current is changed; the current flow direction control diodes D1 and D2 are used for inhibiting the reverse current of the RLC resonance circuit, and when the current is reduced to zero, the current resonance process is ended; after the non-polar capacitor C3, the magnetic ring inductor L2 and the transmitting coil acquire the energy of the energy storage capacitor, the energy storage capacitor is charged first and then discharged, and half sine wave transmitting current is generated.
Referring to fig. 3, the working process of the triangular wave and trapezoidal wave transmitting circuits with controllable turn-off time is divided into four stages, namely, forward power supply stop, reverse power supply and reverse power supply stop.
(1) Forward power supply: the switches Q1 and Q4 are turned on simultaneously, the current in the transmitting coil flows to E-D1-Q1-r-L1-Q4-D4, and when the transmitting current is increased from zero and then reaches a stable value, the transmitting current is trapezoidal wave; when the emission current is increased from zero and then does not reach a stable value, the triangular wave is obtained.
(2) And (3) stopping power supply in the forward direction: the switches Q1 and Q4 are turned off simultaneously, at the same time, the switches Q5, Q6, Q7 and Q8 are turned on, the switches of one group of TVS tubes are kept in an on state all the time, at the same time, one group of TVS tubes in TVS1, TVS2, TVS3 and TVS4 are immediately connected in series with the transmitting coil to generate a clamping voltage V, the power supply voltage is U, t is the moment after the turn-off starts, at the same time, the current in the transmitting coil meets the equation (1), and the turn-off time t is the turn-off time tdSatisfying equation (2), the falling edge slope S satisfies equation (3).
(3) Reverse power supply: switches Q5, Q6, Q7 and Q8 are closed simultaneously, switches Q2 and Q3 are opened simultaneously, the current flow direction in the transmitting coil is E-D3-Q3-L1-r-Q2-D2, and the current flow direction in the transmitting coil is changed at the moment.
(4) And (3) stopping power supply in the reverse direction: switches Q2 and Q3 are turned off simultaneously, at the moment, the switches Q5, Q6, Q7 and Q8 are turned on, a group of TVS tubes and a power resistor R are connected with a transmitting coil in series, and different clamping voltages determine different turn-off time; the power resistor suppresses current overshoot and tail oscillation.
Referring to fig. 4, the operation of the half sine wave transmitter circuit based on the RLC series resonant circuit is divided into two stages, namely, positive half-cycle resonance and negative half-cycle resonance.
(1) Positive half-cycle resonance: the switch Q1 is turned on, the Q17, Q18 and Q19 of the switch switching circuit are kept in an open state, the energy storage capacitor C1 supplies power to the resonant circuit, the current flow direction in the transmitting coil is C1-D1-Q1-r-L1-Q18-C3-L2-Q17-Q19, the half sine wave pulse width satisfies equation (4), generally, the on duration of the switch Q1 is longer than the half sine wave pulse width, and therefore after resonance is completed, under the action of the diode D1, the transmitting current is kept to be zero and is stabilized.
(2) Negative half-cycle resonance: the switch Q2 is turned on, the switch Q1 is turned off, the Q17, the Q18 and the Q19 of the switch switching circuit are kept in an open state, at the moment, the energy storage capacitor C2 supplies power to the resonant circuit, the current flow direction in the transmitting coil is C2-Q17-L2-C3-Q18-L1-r-Q2-D2, the half sine wave transmitting current flow direction is changed, the opening duration of the switch Q2 is the same as the opening duration of the switch Q1, and after resonance is completed, the transmitting current is kept to be zero and stabilized under the action of the diode D2.
The combined emission current of the trapezoidal waves and the triangular waves is eight stages, namely forward trapezoidal wave emission, forward stop emission, forward triangular wave emission, forward stop emission, reverse trapezoidal wave emission, reverse stop emission, reverse triangular wave emission and reverse stop emission; the combined emission current of the trapezoidal waves and the half sine waves is six stages, namely forward trapezoidal wave emission, forward stop emission, positive half-cycle resonance, reverse trapezoidal wave emission, reverse stop emission and negative half-cycle resonance; the triangular wave and half sine wave combined emission current is six stages, namely forward triangular wave emission, forward stop emission, positive half-cycle resonance, reverse triangular wave emission, reverse stop emission and negative half-cycle resonance.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (7)
1. A time domain three-waveform combined electromagnetic emission system and a control method are characterized in that: the device comprises an external power supply, a main control circuit, a transmitting bridge circuit, a passive clamping circuit, an absorption circuit and an RLC series resonant circuit; the external power supply supplies power to the transmitting bridge circuit and also charges the energy storage capacitor; the main control circuit is used as a control part of the transmitting system and controls the switch module to work so as to generate different types of transmitting current waveforms; the transmitting bridge circuit is an H bridge circuit formed by four switch modules and provides bipolar trapezoidal wave or triangular wave transmitting current for the transmitting coil; the passive clamping circuit is composed of five groups of switch modules and four groups of transient suppression diodes (TVS), wherein one group of transient suppression diodes are connected in series at two ends of the transmitting coil during the period of transmitting current turn-off to provide a clamping voltage for the transmitting coil; the absorption circuit consists of a group of switch modules and a power resistor and is used for absorbing electric energy of emission current reverse discharge and inhibiting oscillation of the tail part of the current; the RLC series resonance circuit is composed of a transmitting coil, a non-polar capacitor and a magnetic ring inductor, and generates bipolar half sine wave transmitting current under the action of an energy storage capacitor and a switch module.
2. The time-domain three-waveform combined electromagnetic emission system and the control method thereof according to claim 1, wherein: the main control circuit outputs a plurality of paths of PWM waves according to the set emission parameters and drives corresponding switch modules in the emission system through the optocoupler, so that the emission system can be controlled to independently output trapezoidal wave or triangular wave emission current with controllable turn-off time and half sine wave emission current with different pulse widths; the emission current of the combination of the trapezoidal wave and the triangular wave, the combination of the trapezoidal wave and the half sine wave and the combination of the triangular wave and the half sine wave can also be output.
3. The time-domain three-waveform combined electromagnetic emission system and the control method thereof according to claim 1, wherein: the transmitting bridge circuit is switched on and off by four switch modules of the driving bridge circuit through an optical coupler by PWM (pulse width modulation) waves output by the main control circuit, and trapezoidal wave transmitting current with adjustable duty ratio and period can be generated when the pulse width of the PWM waves is more than the inherent rise time between a power supply and a transmitting coil; when the pulse width of the PWM wave is smaller than the inherent rise time, triangular wave emission current with adjustable pulse width and period can be generated.
4. The time-domain three-waveform combined electromagnetic emission system and the control method thereof according to claim 1, wherein: the switch modules in the transmitting bridge circuit, the clamping circuit, the absorption circuit and the RLC series resonant circuit are generally selected from IGBT modules, MOSFET modules or other types of switch modules with high voltage resistance and high current resistance in order to meet the requirement of high-power transmission.
5. The time-domain three-waveform combined electromagnetic emission system and the control method thereof according to claim 1, wherein: the passive clamping circuit consists of a group of main switch modules, four-component switch modules and four groups of transient suppression diodes; the main switch module is controlled by a signal generated by a NOR gate logic circuit, so that the main switch module is closed during the transmitting period and is opened during the transmitting current off period; each group of transient suppression diodes is formed by connecting a plurality of transient suppression diodes with the same clamping voltage value in parallel, the clamping voltages of the four groups of transient suppression diodes are distributed from low voltage to high voltage, the selectable range of the clamping voltages is generally 8.5V to 120V, the group of transient suppression diodes are controlled by the main control circuit to be connected in series at two ends of the transmitting coil during the period of transmitting current turn-off, and the turn-off time of the transmitting current is controlled according to different clamping voltages.
6. The time-domain three-waveform combined electromagnetic emission system and the control method thereof according to claim 1, wherein: the absorption circuit consists of a group of switch modules and a power resistor; the power resistor is controlled by the main control circuit to be connected in series at two ends of the transmitting coil during the period of transmitting current turn-off, and the resistance value of the power resistor is generally 200 times to 500 times of that of the transmitting coil; when a group of transient suppression diodes are connected during the turn-off of the transmitting current, the current in the transmitting coil firstly breaks down the transient suppression diodes to form a loop, and when the energy in the transmitting coil is not enough to maintain the breakdown state of the transient suppression diodes, the power resistor is connected to form a loop with the transmitting coil, so that the power resistor is used for absorbing the residual energy in the transmitting coil and suppressing the overshoot and tail oscillation of the transmitting current; during the turn-off period of the transmitting current, when the transient suppression diode is not connected, the power resistor and the transmitting coil form a loop, the energy in the transmitting coil can be absorbed quickly, and the turn-off time of the transmitting current is reduced.
7. The time-domain three-waveform combined electromagnetic emission system and the control method thereof according to claim 1, wherein: the RLC series resonance circuit is composed of a transmitting coil, a non-polar capacitor and a magnetic ring inductor, wherein a resistor in the transmitting coil and a resistor in the inductor are used as resistors of the resonance circuit, the inductor in the transmitting coil and the magnetic ring inductor are used as inductors of the resonance circuit, and a plurality of high-voltage-resistance non-polar capacitors connected in parallel are used as capacitors of the resonance circuit; an external power supply charges a polar energy storage capacitor, the on-off of the switch module is controlled by the main control circuit, and the two energy storage capacitors respectively supply power to the RLC series resonance circuit to generate bipolar half sine wave emission current; the inductance and capacitance in the RLC series resonant circuit determine the pulse width of the half sine wave transmit current.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115128680A (en) * | 2022-06-28 | 2022-09-30 | 吉林大学 | Transient electromagnetic target measurement method for magnetic source multi-waveform combination |
Citations (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4316242A (en) * | 1980-09-04 | 1982-02-16 | General Electric Company | Wide input range, transient-immune regulated flyback switching power supply |
| US5121314A (en) * | 1991-02-04 | 1992-06-09 | Maxwell Laboratories | Bi-mode high voltage resonant power supply and method |
| JP2000341946A (en) * | 1992-09-25 | 2000-12-08 | Murata Mfg Co Ltd | Operating method of resonance type power supply circuit for high voltage generation |
| CN104407391A (en) * | 2014-12-05 | 2015-03-11 | 吉林大学 | Magnetic source non-modulation type transmitter and control method thereof |
| CN104682763A (en) * | 2015-03-10 | 2015-06-03 | 中国科学院电子学研究所 | Method and device for high-speed off of energy-feedback constant-voltage clamp |
| CN104953884A (en) * | 2015-07-14 | 2015-09-30 | 中国科学院电子学研究所 | Bipolar half-sine current generating device and method for full-ATEM (airborne transient electromagnetic system) |
| US9285496B1 (en) * | 2012-10-22 | 2016-03-15 | White's Electronics, Inc. | Truncated half-sine methods for metal detectors |
| CN105743385A (en) * | 2016-04-26 | 2016-07-06 | 吉林大学 | Current waveform shaping circuit for transient electromagnetic transmitter |
| CN106208734A (en) * | 2016-08-22 | 2016-12-07 | 中国科学院电子学研究所 | Transient electromagnetic exploration system transmitter |
| CN107065020A (en) * | 2017-01-09 | 2017-08-18 | 重庆璀陆探测技术有限公司 | The many ripple investigation systems of twin coil manifold type |
| CN107783196A (en) * | 2017-11-22 | 2018-03-09 | 中国地质大学（武汉） | A kind of Transient Electromagnetic Apparatus emitter |
| CN207301137U (en) * | 2017-09-21 | 2018-05-01 | 吉林大学 | A kind of new transient electromagnetic method pulse current radiating circuit |
| CN107979300A (en) * | 2016-10-19 | 2018-05-01 | 中国科学院电子学研究所 | Big the magnetic moment transmitter and its method of generating current of the trapezoidal electric current of bipolarity |
| 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 |
| CN108227011A (en) * | 2018-02-02 | 2018-06-29 | 吉林大学 | The double-trapezoidal wave emission system and control method of a kind of controllable failing edge |
| CN110515129A (en) * | 2019-08-08 | 2019-11-29 | 吉林大学 | Urban underground space multi-coil pull-type dipole electromagnetic exploration apparatus and method |
| CN111352164A (en) * | 2020-03-20 | 2020-06-30 | 吉林大学 | Transient electromagnetic detection system with large transmitting magnetic moment and short turn-off time |
| CN111965713A (en) * | 2020-07-15 | 2020-11-20 | 中国地质大学（武汉） | Passive constant voltage clamping transient electromagnetic transmitting circuit |
| CN112578466A (en) * | 2020-12-08 | 2021-03-30 | 重庆璀陆探测技术有限公司 | Energy-feedback type constant-voltage double-clamping circuit of transient electromagnetic transmitter and control method thereof |
-
2021
- 2021-11-10 CN CN202111325720.1A patent/CN113866835B/en active Active
Patent Citations (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4316242A (en) * | 1980-09-04 | 1982-02-16 | General Electric Company | Wide input range, transient-immune regulated flyback switching power supply |
| US5121314A (en) * | 1991-02-04 | 1992-06-09 | Maxwell Laboratories | Bi-mode high voltage resonant power supply and method |
| JP2000341946A (en) * | 1992-09-25 | 2000-12-08 | Murata Mfg Co Ltd | Operating method of resonance type power supply circuit for high voltage generation |
| US9285496B1 (en) * | 2012-10-22 | 2016-03-15 | White's Electronics, Inc. | Truncated half-sine methods for metal detectors |
| CN104407391A (en) * | 2014-12-05 | 2015-03-11 | 吉林大学 | Magnetic source non-modulation type transmitter and control method thereof |
| CN104682763A (en) * | 2015-03-10 | 2015-06-03 | 中国科学院电子学研究所 | Method and device for high-speed off of energy-feedback constant-voltage clamp |
| CN104953884A (en) * | 2015-07-14 | 2015-09-30 | 中国科学院电子学研究所 | Bipolar half-sine current generating device and method for full-ATEM (airborne transient electromagnetic system) |
| CN105743385A (en) * | 2016-04-26 | 2016-07-06 | 吉林大学 | Current waveform shaping circuit for transient electromagnetic transmitter |
| CN106208734A (en) * | 2016-08-22 | 2016-12-07 | 中国科学院电子学研究所 | Transient electromagnetic exploration system transmitter |
| CN107979300A (en) * | 2016-10-19 | 2018-05-01 | 中国科学院电子学研究所 | Big the magnetic moment transmitter and its method of generating current of the trapezoidal electric current of bipolarity |
| CN107065020A (en) * | 2017-01-09 | 2017-08-18 | 重庆璀陆探测技术有限公司 | The many ripple investigation systems of twin coil manifold type |
| CN207301137U (en) * | 2017-09-21 | 2018-05-01 | 吉林大学 | A kind of new transient electromagnetic method pulse current radiating circuit |
| CN107783196A (en) * | 2017-11-22 | 2018-03-09 | 中国地质大学（武汉） | A kind of Transient Electromagnetic Apparatus emitter |
| 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 |
| CN108227011A (en) * | 2018-02-02 | 2018-06-29 | 吉林大学 | The double-trapezoidal wave emission system and control method of a kind of controllable failing edge |
| CN110515129A (en) * | 2019-08-08 | 2019-11-29 | 吉林大学 | Urban underground space multi-coil pull-type dipole electromagnetic exploration apparatus and method |
| CN111352164A (en) * | 2020-03-20 | 2020-06-30 | 吉林大学 | Transient electromagnetic detection system with large transmitting magnetic moment and short turn-off time |
| CN111965713A (en) * | 2020-07-15 | 2020-11-20 | 中国地质大学（武汉） | Passive constant voltage clamping transient electromagnetic transmitting circuit |
| CN112578466A (en) * | 2020-12-08 | 2021-03-30 | 重庆璀陆探测技术有限公司 | Energy-feedback type constant-voltage double-clamping circuit of transient electromagnetic transmitter and control method thereof |
Non-Patent Citations (4)
| Title |
|---|
| 于生宝;姜健;孙长玉;陈旭;: "新型航空瞬变电磁法脉冲电流发射电路研究", 中南大学学报(自然科学版), no. 09 * |
| 于生宝;宋树超;许佳男;张嘉霖;陈旭;: "基于幅值追踪法的航空电磁波形优化控制", 中南大学学报(自然科学版), no. 04 * |
| 于生宝;朱占山;姜健;韩哲鑫;: "PWM斩波与恒压钳位控制瞬变电磁发射***", 中南大学学报(自然科学版), no. 03 * |
| 赵逸夫;刘丽华;乔流;耿智;刘小军;: "三角波电流瞬变电磁发射***研制", 电子测量技术, no. 17 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115128680A (en) * | 2022-06-28 | 2022-09-30 | 吉林大学 | Transient electromagnetic target measurement method for magnetic source multi-waveform combination |
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