Electromagnetic exploration emission system overcoming effects of load inductance

Abstract

To provide an electromagnetic exploration emission system that overcomes effects of a load inductance.SOLUTION: An electromagnetic exploration emission system includes an emission circuit and a logic control circuit. The emission circuit is used to emit a high frequency high current, and the logic control circuit is used to generate a drive signal for a switching device in the emission circuit. By connecting the current rapid on / off unit in series with the emission circuit, introducing an auxiliary on / off voltage, and forming a current high voltage emission circuit with a series connection of a plurality of on / off units, the limitation due to a rated voltage of the power device is overcome, and the rapid on / off of the emission current under the large inductive load condition is achieved.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to the field of physics technology for earth exploration, and more particularly to an electromagnetic exploration emission system that overcomes the effects of load inductance. [Background technology]

[0002] Electromagnetic methods utilize differences in the electromagnetic properties of underground media, such as electrical conductivity and magnetic permeability, to observe and study the distribution patterns (frequency or time characteristics) of artificially or naturally formed electromagnetic fields and solve related geological problems by applying the principles of electromagnetic induction. Artificial sources overcome the drawback of natural sources, which have a low signal-to-noise ratio, significantly improving work efficiency, detection accuracy, and detection resolution. Controllable source audio earth electromagnetic methods, wide-area electromagnetic methods, semi-aerial electromagnetic methods, short-offset transient electromagnetic methods, and time-frequency electromagnetic methods use long wiring (1-2 km) and ground electrodes to inject current into the ground to excite artificial electric field sources. Full-aerial electromagnetic methods and ground transient electromagnetic methods use large coil currents to excite artificial magnetic field sources.

[0003] Artificial sources excited by rapidly changing currents can improve detection accuracy and resolution, improving the effectiveness of high-frequency data. The long wiring inductance used to excite artificial electric field sources inhibits current changes and prevents efficient emission of high-frequency currents. Controllable-source audio ground electromagnetic methods based on audio currents cannot observe data over long transmission and reception distances, affecting detection depth. Wide-area electromagnetic methods based on pseudorandom code currents cannot achieve the large, uniform-amplitude, multi-frequency current emission required by the method theory, affecting detection accuracy. Short-offset and semi-airborne electromagnetic methods based on secondary magnetic field decay signal observations cannot obtain reliable initial apparent resistivity data, affecting detection resolution. The large coil inductance required to excite artificial magnetic field sources also inhibits current changes, preventing rapid current changes.

[0004] The international mainstream electric source transmitter products include the TXU-30 transmitter from Phoenix Geophysics of Canada, the GGT-30 transmitter from Zonge of the United States, and the TXM-22 transmitter from Metronix of Germany. In China, existing domestic and international transmitters, such as the GDC-1 transmitter developed by Professor He Jishan's team at Central South University based on the wide-area electromagnetic method, the DEM-T70 transmitter developed by the Institute of Geophysical and Geochemical Exploration (IGGE) of the Chinese Academy of Geological Sciences, the JDD-100 transmitter developed by Jilin University, the 50kW transmitter developed by Beijing University of Technology, the 160kW transmitter developed by China University of Geosciences (Beijing), the 200kW transmitter developed by PetroChina Oriental Geophysical Company, and the 30kW transmitter developed by Chengdu University of Technology, have not been able to overcome the impact of load inductance on emission current. With the development of electromagnetic exploration, overcoming the impact of load inductance on emission current has attracted increasing attention and become an important research direction for electromagnetic transmitters.

[0005] Regarding current-off technology and control of the emission current of large-coil magnetic sources, the China University of Geosciences (Wuhan) proposed a concept of increasing the equivalent resistance of the discharge circuit. By controlling the circuit inductance to 1.2 mH, the emission current to 10 A, and the discharge circuit resistance to 50 Ω, the current-off time was reduced from 1.3 ms to approximately 100 μs. The Institute of Electronics, Chinese Academy of Sciences proposed an energy-supply constant-current / constant-voltage clamp technology emission scheme, which rapidly reduces the induced reflux current through a high-voltage clamp unit and feeds it back to the high-voltage power supply. Jilin University researched a control method using a PWM chopper and constant-voltage clamp and proposed compensation control for time-frequency fusion emission. Existing technologies typically achieve off-times of several hundred μs or more. Longer wiring sources have stronger storage and longer drop times. Regarding rapid current-off from long-wire sources, current literature has achieved an off-time of 53 μs for a 1-km-long wiring. There are currently few related reports on rapid current-on.

[0006] To overcome the influence of inductance on the emission current, conventional technologies focus on applying a high-voltage clamp to the emission bridge. However, this method is limited by the withstand voltage limits of the power devices and cannot adapt to the rapid changes in current in various construction environments. In addition, there is a great risk of overvoltage being concentrated in the transmitter, which reduces the reliability of the system. Summary of the Invention [Problem to be solved by the invention]

[0007] In order to solve the shortcomings of the prior art, the present invention proposes an electromagnetic detection and emission system that overcomes the influence of load inductance, overcomes the withstand voltage limitations of power devices, distributes the high voltage part to the emission circuit through a current on / off unit, and applies auxiliary high voltage to the circuit at the moment of current change, forcing rapid changes in current. [Means for solving the problem]

[0008] To achieve the above objectives, the present invention provides the following solutions:

[0009] 1. An electromagnetic surveillance emission system that overcomes the effects of load inductance, comprising: an emission circuit; and a logic control circuit; The emission circuit is used to emit a high frequency large current, The logic control circuit is used to generate drive signals for switching devices in the emission circuit.

[0010] Preferably, the emission circuit includes an emission power supply, a long wiring inductance, an electrode resistance, an emission bridge, and a current high voltage emission circuit; the emission power supply is used to provide power to the emission system; The discharge bridge is composed of four IGBTs, K1, K2, K3, and K4. The current high voltage discharge circuit is composed of a first on-off unit and a second on-off unit connected in series.

[0011] Preferably, in the discharge circuit: The positive pole of the emission power supply is connected to the collector of K1 and the collector of K3, respectively; The negative pole of the emission power supply is connected to the emitter of K2 and the emitter of K4, respectively; The emitter of K1 is connected to the collector of K2 and is wired to one side of the first on-off unit; The emitter of K3 is connected to the collector of K4 and is wired to one side of the long wiring inductance; The other side of the long wiring inductance is connected to one side of the electrode resistance; The other side of the electrode resistor is connected to one side of the second on-off unit.

[0012] Preferably, the first on-off unit includes a first on-off bridge, a first on-off power supply, and a first on-off switch; The first on-off bridge is composed of four IGBTs S11, S12, S13, and S14. The first on-off switch is configured by a series connection of two IGBTs, one side of the first on-off switch is connected to the discharge circuit, and the other side of the first on-off switch is connected to the second on-off unit; The positive electrode of the first on-off power supply is connected to the collector of the S11 and the collector of the S13, respectively; The negative pole of the first on-off power supply is connected to the emitter of S12 and the emitter of S14, respectively; The emitter of S11 is connected to the collector of S12 and is wired to one side of the first on / off switch; The emitter of S13 is connected to the collector of S14 and is wired to the opposite side of the first on / off switch.

[0013] Preferably, the second on-off unit includes a second on-off bridge, a second on-off power supply, and a second on-off switch; The second on-off bridge is composed of four IGBTs S21, S22, S23, and S24. the second on-off switch is configured by connecting two IGBTs in series, one side of the second on-off switch is connected to the first on-off unit, and the other side of the first on-off switch is connected to the electrode resistor; The positive terminal of the second on-off power supply is connected to the collector of S21 and the collector of S23, respectively; The negative pole of the second on-off power supply is connected to the emitter of S22 and the emitter of S24, respectively; The emitter of S21 is connected to the collector of S22 and is wired to one side of the second on / off switch; The emitter of S23 is connected to the collector of S24 and is wired to the opposite side of the second on / off switch.

[0014] Preferably, the logic control circuit includes a current sensor, an on-off bridge drive circuit, and a discharge bridge drive circuit; the current sensor is disposed between the emission power supply and the emission bridge and connected to the on-off bridge driving circuit, the current sensor being used to collect a current signal of the emission power supply; the emission bridge driving circuit further includes an OR logic gate; The on-off bridge driving circuit includes a diode, a ground capacitor, a comparator, a first AND logic gate, and a second AND logic gate.

[0015] Preferably, the emitting bridge drive circuit is used to generate drive signal A and drive signal B; The drive signal A is used to drive the K1 and K4, and the drive signal B is used to drive the K2 and K3, The drive signal A and the drive signal B are connected to the OR logic gate to generate an on-off switch drive signal, which is used to drive the first on-off switch and the second on-off switch.

[0016] Preferably, the on-off bridge drive circuit comprises: the current sensor is connected to the anode of the diode; the same direction input terminal of the comparator is connected to the cathode of the diode and is grounded via the ground capacitor; the inverting input terminal of the comparator is connected to the current sensor; the output terminals of the comparators are respectively connected to the first AND logic gate and the second AND logic gate; The driving signal A and the output of the comparator are operated by a first AND logic gate, and the output signal is used to drive the S11, the S14, the S21, and the S24; After the driving signal B and the output of the comparator are operated by the second AND logic gate, the output signal is used to drive the S12, S13, S22, and S23. [Effects of the Invention]

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention overcomes the limitations imposed by the rated voltage of power devices by connecting current rapid on / off units (the number of units is not limited) in series to the discharge circuit, introducing an auxiliary on / off voltage, and forming a high-voltage current discharge circuit by connecting multiple on / off units in series, thereby realizing rapid on / off of discharge current under large inductive load conditions. [Brief explanation of the drawings]

[0019] In order to more clearly describe the technical solutions of the present invention, the drawings required in the embodiments are briefly described below. The drawings in the following description are only some embodiments of the present invention, and it is obvious that those skilled in the art can also obtain other drawings from these drawings without creative efforts. [Figure 1] FIG. 1 is a schematic diagram of a basic discharge inverter bridge topology. [Figure 2] FIG. 1 is a schematic diagram of an inverter bridge introducing an off-high voltage. [Figure 3] FIG. 2 is a schematic diagram showing the circuit connections of an embodiment of the present invention incorporating one rapid current on / off circuit unit. [Figure 4] FIG. 1 is a schematic diagram showing the circuit connections of an embodiment of the present invention incorporating two rapid current on / off circuit units. [Figure 5a] 1 is a schematic diagram comparing a current emission waveform according to an embodiment of the present invention with a conventional current emission waveform, showing current waveforms in the frequency domain; [Figure 5b] 1 is a schematic diagram comparing a current emission waveform according to an embodiment of the present invention with a conventional current emission waveform, the current waveform being in the time domain; [Figure 6] 10 is a schematic diagram showing the relationship between the number of on / off units and the magnification for speeding up current on according to an embodiment of the present invention; FIG. [Figure 7] 10 is a schematic diagram showing the relationship between the number of on / off units and the magnification for speeding up current off according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, but it is clear that the described embodiments are only some embodiments of the present invention and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative work fall within the protection scope of the present invention.

[0021] In order to make the above objects, features and advantages of the present invention more clearly comprehensible, the present invention will be described in more detail below in connection with the drawings and specific embodiments.

[0022] Before describing the embodiments, existing technical solutions will be introduced first.

[0023] The transmitter load is primarily determined by the wiring inductance and ground resistance. A conventional emitting bridge topology is shown in Figure 1.

[0024] U DC is the discharge voltage (usually 1000V). K1, K2, K3, and K4 are the IGBT inverter bridge switches, L LOAD is the wiring inductance, R LOAD is the ground resistance. When K1 and K4 (or K2 and K3) are turned on, the emission current is limited by the long wiring inductance and reaches a steady value U DC / R LOAD Gradually increase to:

[0025]

number

[0026] The emission current is a steady state value I o =U DC / R LOAD The time it takes for the current to rise to 90% of the steady-state current is defined as the current on time:

[0027]

number

[0028] At time t1, K1 and K4 (or K2 and K3) are cut off and the emission current gradually decreases:

[0029]

number

[0030] At time t1, the emission current reaches a steady value I o =U DC / R LOAD , the emission current is:

[0031]

number

[0032] When the current is 0, the desired off time t off becomes:

[0033]

number

[0034] Therefore, the current on / off time is proportional to the steady-state emission current and inversely proportional to the applied voltage. DC is the on / off voltage, and U DC The higher the voltage, the faster the current cuts off. LOAD Wiring inductance and R LOAD Since the ground resistance is hardly controllable, the only way to achieve rapid current shutoff is to increase the on-off voltage. Therefore, as shown in Figure 2, the conventional method uses a high-voltage clamp rapid-off topology to apply high voltage to the discharge inverter bridge at the time of current on-off, thereby shortening the off time.

[0035] U DC is the normal discharge voltage at 1000V, and P is the on / off high voltage at 2500V. When K5 is turned on at the on / off time and P is applied to the inverter bridge, equations (2) to (5) show that this method achieves a reduction in the current on / off time. However, this method is limited by the device withstand voltage of the inverter bridge, and the current on / off effect is affected by limitations in the installation environment.

[0036] Embodiment 1

[0037] In this embodiment, a current rapid on / off unit is connected in series to the discharge circuit, and an auxiliary on / off voltage is introduced. The series connection of multiple on / off units forms a high-voltage current discharge circuit, overcoming the limitations imposed by the rated voltage of the power devices and enabling rapid on / off of discharge current even under large inductive load conditions. The high voltage is distributed across the discharge circuit, and the low voltage of the on / off units avoids the withstand voltage limitations of the power devices, ensuring system stability and reliability. The circuit topology is shown in Figure 3.

[0038] When the emission current is activated, the emission bridge diagonal switching device conducts, the on-off switch S in the on-off unit turns off, the on-off bridge diagonal switching device conducts, and the emission current reaches the steady-state value I o =U DC / R LOAD When the emission current reverses, the other diagonal switching device in the emission bridge conducts, the on-off switch S in the on-off unit turns off, the other diagonal switching device in the on-off bridge conducts, and the emission current reaches a steady-state value of -I o =-U DC / R LOAD , at which point the on-off switch S turns on. This process is repeated to achieve the purpose of rapid commutation of high voltage current, and the current commutation voltage can be increased by connecting multiple on-off units in series until the commutation time reaches the reference value.

[0039] Embodiment 2

[0040] In this embodiment, as shown in FIG. 4, the electromagnetic survey emission system that overcomes the influence of load inductance includes an emission circuit and a logic control circuit.

[0041] The discharge circuit is used to discharge high frequency current. The discharge circuit is connected to the discharge power supply U DC , long wiring inductance L LOAD , electrode resistance R LOAD , including a discharge bridge, a current high-voltage discharge circuit, and a discharge power supply U DCis used to supply power to the emission system, the emission bridge is composed of four IGBTs K1, K2, K3 and K4, and the current high voltage emission circuit is composed of a series connection of the first on-off unit and the second on-off unit.

[0042] In the emission circuit, the emission power supply U DC The positive poles of K1 and K3 are connected to the collectors of K1 and K3, respectively, and the discharge power supply U DC The negative poles of K1 and K4 are connected to the emitter of K2 and the collector of K2, respectively, and are wired to one side of the first on-off unit. The emitter of K3 is connected to the collector of K4, and the long wiring inductance L LOAD The long wiring inductance L LOAD The other side is the electrode resistance R LOAD connected to one side of the electrode resistance R LOAD The other side is connected to one side of the second on-off unit.

[0043] The first on-off unit includes a first on-off bridge, a first on-off power supply P1, and a first on-off switch S1. The first on-off bridge is composed of four IGBTs S11, S12, S13, and S14. The first on-off switch S1 is composed of two IGBTs connected in series. The emitters of the two IGBTs are connected together, and the collectors are used as both ends of the first on-off unit. One side of the first on-off switch S1 is connected to a discharge circuit. The other side of the first on-off switch S1 is connected to the second on-off unit, the positive pole of the first on-off power supply P1 is connected to the collector of S11 and the collector of S13 respectively, the negative pole of the first on-off power supply P1 is connected to the emitter of S12 and the emitter of S14 respectively, the emitter of S11 is connected to the collector of S12 and wired to one side of the first on-off switch S1, and the emitter of S13 is connected to the collector of S14 and wired to the other side of the first on-off switch S1.

[0044] The second on-off unit includes a second on-off bridge, a second on-off power supply P2, and a second on-off switch S2. The second on-off bridge is composed of four IGBTs S21, S22, S23, and S24. The second on-off switch S2 is composed of two IGBTs connected in series. The emitters of the two IGBTs are connected together, and the collectors are used as both ends of the second on-off unit, respectively. One side of the second on-off switch S2 is connected to the first on-off unit, and the other side of the first on-off switch S1 is connected to the electrode resistance R LOAD The positive electrode of the second on-off power supply P2 is connected to the collector of S21 and the collector of S23, respectively, the negative electrode of the second on-off power supply P2 is connected to the emitter of S22 and the emitter of S24, respectively, the emitter of S21 is connected to the collector of S22 and is wired to one side of the second on-off switch S2, and the emitter of S23 is connected to the collector of S24 and is wired to the other side of the second on-off switch S2.

[0045] The logic control circuit is used to generate drive signals for the switching devices in the emission circuit.

[0046] The logic control circuit includes a current sensor, an on-off bridge driving circuit, and an emission bridge driving circuit, wherein the current sensor is installed between the emission power supply and the emission bridge and connected to the on-off bridge driving circuit, the current sensor is used to collect a current signal of the emission power supply, the emission bridge driving circuit further includes an OR logic gate OR, and the on-off bridge driving circuit includes a diode D, a ground capacitor C, a comparator COM, a first AND logic gate AND1, and a second AND logic gate AND2.

[0047] Here, the emission bridge driving circuit is used to generate driving signal A and driving signal B, driving signal A is used to drive K1 and K4, driving signal B is used to drive K2 and K3, driving signal A and driving signal B are connected to an OR logic gate OR to generate an on-off switch driving signal, which is used to drive the first on-off switch S1 and the second on-off switch S2.

[0048] In the on-off bridge drive circuit, the current sensor is connected to the anode of diode D, the inverting input terminal of comparator COM is connected to the cathode of diode D and grounded to ground C via a ground capacitor, the inverting input terminal of comparator COM is connected to the current sensor, and the output terminal of comparator COM is connected to the first AND logic gate AND1 and the second AND logic gate AND2, respectively. After the drive signal A and the output of comparator COM are calculated by the first AND logic gate AND1, the output signal is used to drive S11, S14, S21, and S24, and after the drive signal B and the output of comparator COM are calculated by the second AND logic gate AND2, the output signal is used to drive S12, S13, S22, and S23.

[0049] In this embodiment, the on / off unit is set to 3000V, the emission voltage to 1000V, the load resistance to 50Ω, the load inductance to 3mH, and the steady-state emission current to 20A. 20A is used as the reference current and is connected to the positive input of the comparator, and the DC bus current is connected to the negative input of the comparator. The output of the comparator is connected to one input of two AND gates, AND1 and AND2, and the other input of the AND gate is connected to the two drive signals of the emission bridge. The outputs of the AND gates drive the two diagonal switches of the on / off unit, respectively. The two drive signals of the emission bridge are connected to the inputs of the OR gate, OR, and the output of the OR gate is connected to the main switch of the on / off unit. The frequency of the current waveform in the frequency domain of the electromagnetic method is calculated to be 10kHz, and the frequency of the current waveform in the time domain is 1kHz. Figure 5 shows a comparison of the current emission waveform of this invention with that of a conventional technology.

[0050] The simulation results show that the commutation time of the output current waveform of the present invention is significantly reduced, and the frequency domain current waveform quickly reaches a steady state of 20A, while the conventional emission current commutation time is too long, it has not yet reached the steady state of 20A and is then forcibly commutated, resulting in a very small emission effective current. The time domain current waveform quickly turns on and off, demonstrating a significant advantage of the emission current waveform technology over the conventional method.

[0051] Embodiment 3

[0052] In this embodiment, the number of on / off units can be increased without limit, so that the purpose of increasing the current commutation voltage can be achieved, and the number of on / off units connected in series can be increased according to the demand for current on / off time until the index requirement is met.

[0053] The technical effect of using N on-off units is verified by the formula.

[0054] If the emission voltage is equal to the voltage of the on-off unit and the number of on-off units is N, the current on-time can be deduced from equation (1) as follows:

[0055]

number

[0056] Normalize the on-time without the on-off unit to get the scaling parameter that speeds up the current on of the on-off unit:

[0057]

number

[0058] The current off time is:

[0059]

number

[0060] Normalize the off time under the condition without the on-off unit to obtain the scaling factor parameter that speeds up the current off of the on-off unit:

[0061]

number

[0062] From the above equations, we can obtain the relationship between the number of on-off units and the magnification factor for speeding up the current on, as shown in Figure 6, and the relationship between the number of on-off units and the magnification factor for speeding up the current off, as shown in Figure 7.It can be seen that adding on-off units rapidly shortens the current on-off time, and the speed of shortening gradually slows down as the number of on-off units increases.

[0063] The above-described embodiments merely describe preferred aspects of the present invention and do not limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the design spirit of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. a discharge circuit and a logic control circuit; The emission circuit is used to emit a high frequency large current, 10. An electromagnetic surveillance emission system for overcoming the effects of load inductance, wherein the logic control circuit is used to generate a drive signal for a switching device in the emission circuit.

2. The emission circuit includes an emission power supply, a long wiring inductance, an electrode resistance, an emission bridge, and a current high voltage emission circuit; the emission power supply is used to provide power to the emission system; The discharge bridge is composed of four IGBTs K1, K2, K3, and K4.

2. The electromagnetic exploration emission system for overcoming the influence of load inductance as claimed in claim 1, wherein the current high voltage emission circuit is composed of a first on-off unit and a second on-off unit connected in series.

3. In the discharge circuit, The positive electrode of the emission power supply is connected to the collector of K1 and the collector of K3, respectively; The negative pole of the emission power supply is connected to the emitter of K2 and the emitter of K4, respectively; The emitter of K1 is connected to the collector of K2 and is wired to one side of the first on-off unit; The emitter of K3 is connected to the collector of K4 and is wired to one side of the long wiring inductance; The other side of the long wiring inductance is connected to one side of the electrode resistance; 3. The electromagnetic exploration emission system for overcoming the influence of load inductance as claimed in claim 2, wherein the other side of the electrode resistor is connected to one side of the second on-off unit.

4. the first on-off unit includes a first on-off bridge, a first on-off power supply, and a first on-off switch; The first on-off bridge is composed of four IGBTs S11, S12, S13, and S14, the first on-off switch is configured by a series connection of two IGBTs, one side of the first on-off switch is connected to the discharge circuit, and the other side of the first on-off switch is connected to the second on-off unit; The positive electrode of the first on-off power supply is connected to the collector of the S11 and the collector of the S13, respectively; The negative electrode of the first on-off power supply is connected to the emitter of S12 and the emitter of S14, respectively; The emitter of the S11 is connected to the collector of the S12 and is wired to one side of the first on / off switch; 3. The electromagnetic exploration emission system for overcoming the influence of load inductance as claimed in claim 2, wherein the emitter of S13 is connected to the collector of S14 and wired to the opposite side of the first on / off switch.

5. the second on-off unit includes a second on-off bridge, a second on-off power supply, and a second on-off switch; The second on-off bridge is composed of four IGBTs S21, S22, S23, and S24, the second on-off switch is configured by connecting two IGBTs in series, one side of the second on-off switch is connected to the first on-off unit, and the other side of the first on-off switch is connected to the electrode resistor; The positive electrode of the second on-off power supply is connected to the collector of the S21 and the collector of the S23, respectively; The negative pole of the second on-off power supply is connected to the emitter of S22 and the emitter of S24, respectively; The emitter of the S21 is connected to the collector of the S22 and is wired to one side of the second on / off switch; 5. The electromagnetic exploration emission system for overcoming the influence of load inductance as claimed in claim 4, wherein the emitter of said S23 is connected to the collector of said S24 and is wired to the opposite side of said second on / off switch.

6. the logic control circuit includes a current sensor, an on-off bridge drive circuit, and a discharge bridge drive circuit; the current sensor is disposed between the emission power supply and the emission bridge and connected to the on-off bridge driving circuit, the current sensor being used to collect a current signal of the emission power supply; the emission bridge driving circuit further includes an OR logic gate; 6. The electromagnetic survey emission system for overcoming the influence of load inductance as claimed in claim 5, wherein the on-off bridge drive circuit includes a diode, a ground capacitor, a comparator, a first AND logic gate, and a second AND logic gate.

7. The emitting bridge driver circuit is used to generate a drive signal A and a drive signal B; The drive signal A is used to drive the K1 and K4, and the drive signal B is used to drive the K2 and K3, 7. The electromagnetic exploration emission system for overcoming the influence of load inductance as claimed in claim 6, wherein the drive signal A and the drive signal B are connected to the OR logic gate to generate an on-off switch drive signal, and the on-off switch drive signal is used to drive the first on-off switch and the second on-off switch.

8. In the on-off bridge drive circuit, the current sensor is connected to the anode of the diode; the same direction input terminal of the comparator is connected to the cathode of the diode and is grounded via the ground capacitor; the inverting input terminal of the comparator is connected to the current sensor; the output terminals of the comparators are respectively connected to the first AND logic gate and the second AND logic gate; The driving signal A and the output of the comparator are operated by a first AND logic gate, and the output signal is used to drive the S11, the S14, the S21, and the S24; 8. The electromagnetic exploration and emission system for overcoming the influence of load inductance as claimed in claim 7, wherein the driving signal B and the output of the comparator are operated by the second AND logic gate, and the output signal is used to drive S12, S13, S22 and S23.

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