Low-voltage high-magnetic-moment transient electromagnetic emission mechanism and method based on multi-parallel coil and single H-bridge driving

Abstract

The invention discloses a low-voltage high-magnetic-moment transient electromagnetic emission mechanism and method based on multi-parallel coil and single H bridge driving, and belongs to the technical field of emission systems. The low-voltage high-magnetic-moment transient electromagnetic emission mechanism comprises an emission control unit and an isolation driving unit connected with the emission control unit; the power driving unit is connected with the isolation driving unit, the H-bridge power output unit is connected with the power driving unit, and the parallel coil load unit is connected with the H-bridge power output unit. The parallel coil load unit is composed of a plurality of sub-coils, the parameters of the sub-coils are consistent, and the two ends of the sub-coils are connected to the output end of the H-bridge power output unit in parallel. According to the invention, a single H bridge drives multiple coils to be connected in parallel, and the inductance of the parallel coils is optimized, so that the problems of difficulty in maintaining magnetic moment output, inductance reduction, steep falling edge, heat dissipation optimization, driver number simplification and the like under low voltage are solved, and the launching mechanism which still maintains equivalent magnetic moment output under low driving voltage is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of launch systems in transient electromagnetic geophysical exploration equipment, specifically relating to a low-voltage, high-magnetic-moment transient electromagnetic launch mechanism and method based on multiple parallel coils and a single H-bridge drive. Background Technology

[0002] Transient electromagnetic (TEM) exploration is an important tool in geophysical exploration for studying subsurface electrical structures. Its transmitting system relies on a high-power coil to rapidly generate a pulsed magnetic field, thereby inducing eddy currents in the subsurface medium. Traditional TEM transmitting systems typically employ a single large coil, driven by a single H-bridge or high-voltage power supply, to achieve a high magnetic moment output. However, to achieve sufficient magnetic field strength, single-coil systems require high-voltage power supplies, which not only increases system cost but also introduces electrical safety risks. Furthermore, due to the large inductance of a single coil, the current fall-off edge at turn-off is slow, resulting in limited early TEM signal response time and a less than ideal signal-to-noise ratio. Simultaneously, the poor heat dissipation of the coil system leads to significant temperature rise over long periods, limiting the output current and magnetic moment.

[0003] Existing improvement schemes mostly employ multi-H-bridge multi-path drives, with each H-bridge driving a group of coils to share the current load. While this method can alleviate the current load problem of a single H-bridge, it also significantly increases circuit complexity, leading to a substantial increase in system cost, complex synchronization control, decreased reliability, complex wiring, and increased space occupation. During commissioning and maintenance, multi-H-bridge drive systems also require ensuring synchronization among all units; otherwise, uneven magnetic moments and pulse signal distortion may occur, further affecting early signal quality.

[0004] Existing solutions also involve using electronic switches to change the coil connection during the turn-off phase, such as switching coils that were originally connected in series to a parallel structure during the turn-off phase, in order to accelerate the energy release process. However, such solutions typically require multiple sets of segmented electronic switches, parallel discharge branches, or energy feedback loops. The coil connection method dynamically switches between the conduction and turn-off phases, resulting in a complex system structure, cumbersome control logic, a large number of components, and high requirements for synchronization and reliability.

[0005] A comprehensive review of existing TEM launch systems reveals their main shortcomings in the following aspects:

[0006] First, there is the issue of high-voltage drive for single-coil systems. Traditional single-coil structures require high drive voltages to obtain sufficient magnetic moment, which is not conducive to the application of low-voltage power supply platforms and also increases system costs and safety risks.

[0007] Second, the equivalent inductance is relatively large, limiting the turn-off characteristics. The large self-inductance of a single coil results in a insufficiently steep current fall-off edge at the moment of turn-off, affecting the effectiveness of the early signal window and the signal-to-noise ratio.

[0008] Third, insufficient heat dissipation. With the current concentrated in a single coil, long-term operation can easily lead to a significant increase in coil temperature, limiting the continuous emission current and the improvement of magnetic moment.

[0009] Fourth, existing solutions that improve turn-off characteristics through coil reconfiguration during the turn-off phase typically rely on multiple sets of electronic switches and discharge networks to switch the connection mode between series connection during the energizing phase and parallel connection during the turn-off phase. This results in a complex system structure, a large number of components, and significant difficulties in wiring and control, which negatively impacts reliability and maintainability. Summary of the Invention

[0010] To address the limitations of existing technologies that cannot simultaneously achieve high magnetic moment output, fast turn-off characteristics, structural simplification, and high reliability under low drive voltage conditions, this invention provides a low-voltage, high magnetic moment transient electromagnetic transmitter mechanism based on multiple parallel coils and a single H-bridge drive. Through a transmitter control unit, an isolation drive unit, a power drive unit, an H-bridge power output unit, and a parallel coil load unit, it can maintain or even increase the magnetic moment output while reducing the drive voltage. Simultaneously, it reduces the equivalent inductance of the coils, resulting in a steeper turn-off current fall-off edge and improved early signal quality. The simplified structure reduces the number of drivers, improving system reliability and maintainability.

[0011] According to a first aspect of the present invention, a low-voltage, high-magnetic-moment transient electromagnetic transmitting mechanism based on multiple parallel coils and a single H-bridge drive is provided, comprising: a transmitting control unit, an isolation drive unit connected to the transmitting control unit, a power drive unit connected to the isolation drive unit, an H-bridge power output unit connected to the power drive unit, and a parallel coil load unit connected to the H-bridge power output unit; the parallel coil load unit is composed of multiple sub-coils, each sub-coil having identical parameters, and its two ends are respectively connected in parallel to the output terminal of the H-bridge power output unit. The identical parameters of each sub-coil refer to the identical wire diameter, shape, number of turns, and winding direction of each sub-coil.

[0012] As a further technical solution, the transmission control unit is used to generate transmission control signals, which are sent to the power drive unit via an isolation drive unit. This solution ensures that the timing of the transmission control signals is strictly synchronized with the receiving module, providing a precise control basis for low-voltage, high-magnetic-moment transmission and improving stability and adaptability.

[0013] As a further technical solution, the isolation drive unit is used to electrically isolate the control signals. This solution protects the transmit control unit from power circuit noise, improving anti-interference capability and operational safety.

[0014] As a further technical solution, the power drive unit is used to receive electrically isolated control signals and perform drive-level processing on them to form corresponding gate drive signals, which are then output to each power switching device in the H-bridge power output unit. This solution enhances signal drive capability, prevents H-bridge arms from being shot-through short-circuited, ensures fast and reliable switching of switching devices, and improves power conversion efficiency and dynamic response speed.

[0015] As a further technical solution, the H-bridge power output unit is used to receive the gate drive signal sent by the power drive unit and drive the parallel coil load unit. This solution realizes forward and reverse current excitation and fast turn-off of the parallel coil, simplifies the circuit structure through a single H-bridge, reduces complexity and cost, and ensures the controllability of transient electromagnetic polarity.

[0016] As a further technical solution, the parallel coil load unit, driven by the H-bridge power output unit, is used to split the original single coil into multiple sub-coils, outputting low-voltage, high-magnetic-moment transient electromagnetic signals. This solution achieves high current peak and magnetic moment output at low supply voltage, accelerates current turn-off speed to improve early signal effectiveness, and simultaneously enhances transmission uniformity and detection resolution through current sharing design.

[0017] According to a second aspect of the present invention, a low-voltage, high-magnetic-moment transient electromagnetic emission method based on multiple parallel coils and a single H-bridge drive is provided, comprising:

[0018] The transmission control unit generates a transmission control signal, which is then electrically isolated by the isolation drive unit and sent to the power drive unit.

[0019] After receiving the electrically isolated control signal, the power drive unit performs drive-level processing on it and generates a corresponding gate drive signal to be output to the H-bridge power output unit.

[0020] The H-bridge power output unit responds to the gate drive signal and directly drives multiple sub-coils in the parallel coil load unit through the switching action of its power switching device, thereby realizing the forward conduction, reverse conduction, and turn-off states of the current.

[0021] Using a low-voltage, high-magnetic-moment transient electromagnetic emission method based on multiple parallel coils and a single H-bridge drive, the magnetic moment output can be maintained or even increased while reducing the driving voltage. At the same time, the equivalent inductance of the coil is reduced, making the turn-off current falling edge steeper and improving early signal quality.

[0022] As a further technical solution, the H-bridge power output unit achieves high magnetic moment transient electromagnetic output and improved turn-off characteristics under low driving voltage without switching the coil connection mode through electronic switches.

[0023] As a further technical solution, the method further includes: during the entire conduction and turn-off phases, the plurality of sub-coils remain connected in parallel.

[0024] According to a third aspect of the present invention, a detection device is provided that integrates a low-voltage, high-magnetic-moment transient electromagnetic emission mechanism based on multiple parallel coils and a single H-bridge drive, comprising:

[0025] Electromagnetic launching mechanism, used to output high magnetic moment transient electromagnetic waves under low driving voltage;

[0026] The receiving module is used to collect underground induction response signals after the electromagnetic transmitting mechanism is turned off.

[0027] The data processing module is used to sample, store, and invert underground induction response signals.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. This invention drives multiple coils in parallel using a single H-bridge (H-bridge power output unit), which can maintain or even increase the magnetic moment output while reducing the drive voltage. Simultaneously, it reduces the equivalent inductance of the coils, making the turn-off current fall-off edge steeper and improving early signal quality. The simplified structure reduces the number of drivers, improving system reliability and maintainability.

[0030] 2. This invention solves the problems of difficulty in maintaining magnetic moment output under low voltage, reduced inductance, steep falling edge, heat dissipation optimization, and simplification of driver quantity by optimizing the parallel coil inductance, thereby achieving the synchronization and reliability brought by the single driver structure. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a diagram of a low-voltage, high-magnetic-moment transient electromagnetic launch mechanism based on multiple parallel coils and a single H-bridge driven according to an embodiment of the present invention.

[0033] Figure 2This is a schematic diagram of an H-bridge driving a single coil according to an embodiment of the present invention, and a circuit diagram of dividing the single coil into m equal parts and connecting them in parallel to the H-bridge. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] like Figure 1 As shown, a low-voltage, high-magnetic-moment transient electromagnetic transmission mechanism based on multiple parallel coils and a single H-bridge drive includes: a transmission control unit, an isolation drive unit connected to the transmission control unit, a power drive unit connected to the isolation drive unit, an H-bridge power output unit connected to the power drive unit, and a parallel coil load unit connected to the H-bridge power output unit. The parallel coil load unit consists of multiple sub-coils, each with identical parameters, and both ends of each sub-coil are connected in parallel to the output terminal of the H-bridge power output unit. The identical parameters of each sub-coil refer to the identical wire diameter, shape, number of turns, and winding direction of each sub-coil.

[0037] Specifically, the transmission control signal is generated by the transmission control unit and sent to the power drive unit after being isolated by an optocoupler (a specific method of electrical isolation). The isolation drive unit is used to achieve electrical isolation between the transmission control unit and the power drive unit, and the electrical isolation is preferably achieved through the optocoupler to suppress the interference of voltage changes (dv / dt) and high-current switching processes on the control system, thereby improving system safety and anti-interference capability.

[0038] Specifically, after receiving the optocoupler-isolated drive signal, the power drive unit performs drive-level processing, including signal shaping, level conversion, and interlocking and dead-time control of the upper and lower bridge arms. This ensures that the transmit control signal meets the requirements of the H-bridge power switching devices for drive voltage, current, and switching timing, and generates corresponding gate drive signals which are output to each power switching device in the H-bridge power output unit. By outputting the gate drive signals, the power drive unit enables each power switching device in the H-bridge power output unit to enter a preset on or off state, thereby controlling the forward, reverse, and off states of the current in the parallel coil load unit.

[0039] Specifically, the output terminal of the H-bridge power output unit is not connected to a single multi-turn coil, but to a parallel coil load unit composed of multiple sub-coils. The multiple sub-coils are multi-strand coils obtained by splitting the original single coil. Each sub-coil has the same parameters, and its two ends are connected in parallel to the output terminal of the H-bridge power output unit to form a single equivalent load.

[0040] Specifically, the parallel coil load unit splits the original single transmitting coil into multiple sub-coils with consistent parameters, and maintains a parallel connection throughout the entire conduction and turn-off phases. The connection relationship does not change with the operating state. It is directly driven by a single H-bridge power output unit, thereby achieving high equivalent magnetic moment output (low voltage high magnetic moment transient electromagnetic) and improved turn-off characteristics under low driving voltage without switching the coil connection mode through electronic switches.

[0041] Specifically, the parallel coil load unit reduces the equivalent inductance and equivalent resistance of the coils by connecting multiple strands in parallel, thereby increasing the total current. This allows for magnetic moment output comparable to that of a single coil under low drive voltage conditions. Simultaneously, the reduced equivalent inductance accelerates the current rise rate within the coil, resulting in a steeper current fall edge at turn-off, improving the signal-to-noise ratio and response accuracy of early signals. Furthermore, the coil shunt reduces the thermal load on a single coil, achieving better heat dissipation.

[0042] Specifically, in the transmitting mechanism of this embodiment, the parallel coil load unit does not have an electronic switch for changing the series-parallel relationship of the coils, nor does it have a parallel discharge branch or energy feedback loop. The H-bridge power output unit always faces a parallel coil load unit with a fixed structure. Through the low-voltage, high-magnetic-moment transient electromagnetic transmitting mechanism, the transmitting control signal acts on the parallel coil load unit only through a unidirectional path of "control signal → isolation → drive → H-bridge". The parallel coil structure itself does not participate in the switching of the control logic. By reducing the equivalent inductance and equivalent impedance caused by the parallel connection of multiple coils, a larger total current and equivalent magnetic moment can be obtained under a lower driving voltage condition. At the same time, a steeper current falling edge is formed during the turn-off phase, thereby improving the time resolution and signal-to-noise ratio of the early transient electromagnetic signal.

[0043] Specifically, such as Figure 2 As shown, the left side is a schematic diagram of the original H-bridge driving a single coil, and the right side is a schematic diagram of the circuit after the single coil is divided into m parts and connected in parallel to the H-bridge. After the original single coil is divided into m parts, under the premise of keeping the total number of turns N, the area of ​​each share S, and the number of turns of each branch being the same and tightly coupled, the following derivation relationship is obtained, as described by formulas (1)-(5) regarding the derivation relationship between current, magnetic moment and current change rate.

[0044] Specifically, such as Figure 2As shown, the left side is a schematic diagram of the original H-bridge driving a single coil, and the right side is a schematic diagram of the circuit after the single coil is divided into m equal parts and connected in parallel to the H-bridge. After the original single coil is divided into m equal parts, under the premise of keeping the total number of turns N, the area of ​​each share S, and the number of turns of each branch being the same and tightly coupled, the following derivation relationship exists, as described by formulas (1)-(5) regarding the derivation relationship between current, magnetic moment and current change rate. Let the resistance of the original coil be R, the self-inductance of the original coil be L, and the driving voltage be V. cc The original steady-state current is The original magnetic moment expression is: (1) After dividing the coil into m equal parts, the number of turns in each part is... The DC resistance of each component is approximately (The number of turns and resistance are approximately linearly related). Under constant voltage drive, the steady-state current per unit is expressed as: (2) Therefore, the expression for the magnetic moment of each coil is: (3) That is, the magnetic moment of each component is the same as the magnetic moment of the original single-strand coil. When all m components are connected in parallel, the total magnetic moment is: (4) In other words, under constant voltage driving conditions, the total magnetic moment increases to m times its original value. Similarly, if we want to maintain the original magnetic moment, the required driving voltage only needs to be one-m times the original value. For the falling edge, the initial rise rate (t→0): i.e. Increase approximately The falling edge is steeper, allowing more early signals to be preserved.

[0045] (5) Where, orig represents the original single-coil structure, par represents the parallel coil structure, and L eq This represents the equivalent inductance when coils are connected in parallel.

[0046] Example 2

[0047] A low-voltage, high-magnetic-moment transient electromagnetic emission method based on multiple parallel coils and a single H-bridge drive, comprising the following steps:

[0048] The transmit control unit generates a transmit control signal, which is electrically isolated by the isolation drive unit and then sent to the power drive unit. Upon receiving the electrically isolated control signal, the power drive unit performs drive-level processing, such as signal shaping, level conversion, and interlocking and dead-time control of the upper and lower bridge arms, ensuring that the transmit control signal meets the requirements of the H-bridge power switching devices for drive voltage, current, and switching timing. This generates a corresponding gate drive signal, which is then output to the H-bridge power output unit. Upon receiving the gate drive signal, the H-bridge power output unit causes each power switching device in the H-bridge power output unit to enter a preset on or off state, corresponding sequentially to the H-bridge's forward rotation mode (forward conduction), reverse rotation mode (reverse conduction), and freewheeling turn-off mode (turn-off state). The parallel coil load unit is directly driven by the H-bridge power output unit, controlling the forward conduction, reverse conduction, and turn-off states of the currents corresponding to multiple sub-coils in the parallel coil load unit. This achieves high equivalent magnetic moment output (low-voltage high magnetic moment transient electromagnetics) and improved turn-off characteristics at low drive voltages without switching the coil connection method via electronic switches. Among them, the parallel coil load unit itself does not participate in the switching of control logic. It always maintains the parallel connection state throughout the entire conduction and turn-off phases. Its connection relationship does not change with the working state. By reducing the equivalent inductance and equivalent impedance brought about by the parallel connection of multiple coils, a larger total current and equivalent magnetic moment can be obtained under lower drive voltage conditions. At the same time, a steeper current falling edge is formed in the turn-off phase, thereby improving the time resolution and signal-to-noise ratio of the early transient electromagnetic signal.

[0049] Example 3

[0050] A detection device integrating a low-voltage, high-magnetic-moment transient electromagnetic transmission mechanism based on multiple parallel coils and a single H-bridge drive includes an electromagnetic transmission mechanism, a receiving module, and a data processing module. The electromagnetic transmission mechanism includes a transmission control unit, an isolation drive unit connected to the transmission control unit, a power drive unit connected to the isolation drive unit, an H-bridge power output unit connected to the power drive unit, and a parallel coil load unit connected to the H-bridge power output unit. The parallel coil load unit consists of multiple sub-coils with identical parameters, and its two ends are connected in parallel to the output terminals of the H-bridge power output unit. The transmission control unit generates transmission control signals and sets transmission timing parameters. The isolation drive unit provides electrical isolation between the transmission control unit and the power drive unit. The power drive unit controls the gate drive of the power switching devices in the H-bridge power output unit. The H-bridge power output unit generates a polarity-switchable drive voltage based on the gate drive signal. The parallel coil load unit, composed of multiple sub-coils connected in parallel, generates a transient electromagnetic transmission magnetic field. The receiving module is used to acquire underground induced response signals after transmission is turned off; the data processing structure is used to sample, store, and invert the underground induced response signals. The detection device generates a transmitting magnetic field by driving a parallel coil load unit with a single H-bridge, achieving high magnetic moment output under low-voltage power supply conditions. The parallel coil structure reduces the equivalent inductance and improves the transmission current turn-off speed, thereby improving the effectiveness of the early signal of the detection system. The detection device can also be applied to ground-based transient electromagnetic detection systems, airborne transient electromagnetic detection systems, or well-drilled transient electromagnetic detection systems.

[0051] Specifically, the transmission control unit, as the timing and command core of the detection device, is responsible for generating precise transmission control signals and setting key transmission timing parameters, including pulse width, repetition frequency, and off-time. The isolation drive unit connects the transmission control unit and the power drive unit, achieving complete electrical isolation of the control signals. This ensures that interference and high voltage generated by the back-end power circuitry do not affect the sensitive control logic at the front end, guaranteeing system stability and safety. The power drive unit receives the isolated control signals and performs level conversion and drive capability enhancement, forming gate drive signals sufficient for fast and reliable control of high-power switching devices. The H-bridge power output unit, consisting of four high-power switching devices forming a full-bridge topology, is directly controlled by the aforementioned gate drive signals. Through precise switching timing logic, it generates a pulse drive voltage with switchable polarity and controllable amplitude on the DC bus voltage. The parallel coil load unit consists of multiple sub-coils with identical or strictly matched parameters connected in parallel. It directly serves as the load for the H-bridge power output unit. Its equivalent inductance is significantly lower than that of a single coil of the same size, resulting in a higher current rise rate and peak current under the same driving voltage, thus achieving high magnetic moment output under low voltage conditions. Simultaneously, the low inductance characteristic of the parallel structure, combined with the active turn-off capability of the H-bridge, greatly improves the turn-off speed of the transmitting current, effectively compressing the turn-off time and laying the foundation for acquiring high-quality early signals. The receiving module starts working within a preset time window after the transmitting current is completely turned off, acquiring the secondary field electromagnetic response signal induced by the underground geological body through a high-sensitivity sensor. The data processing module amplifies, filters, performs analog-to-digital conversion, digital averaging, and stores the weak signal acquired by the receiving module, and further processes it through a dedicated inversion algorithm to ultimately obtain the electrical structure distribution information of the underground medium. This detection device integrates the core advantages of low-voltage power supply, high magnetic moment emission, and fast turn-off through an innovative load architecture that drives multiple parallel coils with a single H-bridge. It significantly improves transient electromagnetic detection systems, especially the early signal quality and effectiveness that are crucial for shallow or high-resolution detection. Its structural design is suitable for various transient electromagnetic detection systems with strict requirements on power supply voltage, system weight, and response speed.

[0052] Finally, it should be noted that the above specific embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above specific embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above specific embodiments based on the technical essence of the present invention should be considered within the protection scope of the present invention.

Claims

1. A low-voltage, high-magnetic-moment transient electromagnetic launching mechanism based on multiple parallel coils and a single H-bridge drive, characterized in that, include: The system comprises a launch control unit, an isolation drive unit connected to the launch control unit, a power drive unit connected to the isolation drive unit, an H-bridge power output unit connected to the power drive unit, and a parallel coil load unit connected to the H-bridge power output unit. The parallel coil load unit consists of multiple sub-coils with identical parameters, and its two ends are connected in parallel to the output terminals of the H-bridge power output unit.

2. The low-voltage, high-magnetic-moment transient electromagnetic launching mechanism based on multiple parallel coils and a single H-bridge drive according to claim 1, characterized in that, The transmission control unit is used to generate a transmission control signal, which is sent to the power drive unit via the isolation drive unit.

3. The low-voltage, high-magnetic-moment transient electromagnetic launching mechanism based on multiple parallel coils and a single H-bridge drive according to claim 1, characterized in that, The isolation drive unit is used to electrically isolate the control signals.

4. The low-voltage, high-magnetic-moment transient electromagnetic launching mechanism based on multiple parallel coils and a single H-bridge drive according to claim 1, characterized in that, The power drive unit is used to receive electrically isolated control signals and perform drive-level processing on them to form corresponding gate drive signals, which are then output to each power switching device in the H-bridge power output unit.

5. The low-voltage, high-magnetic-moment transient electromagnetic launching mechanism based on multiple parallel coils and a single H-bridge drive according to claim 1, characterized in that, The H-bridge power output unit is used to receive the gate drive signal sent by the power drive unit and drive the parallel coil load unit.

6. The low-voltage, high-magnetic-moment transient electromagnetic launching mechanism based on multiple parallel coils and a single H-bridge drive according to claim 1, characterized in that, The parallel coil load unit is driven by the H-bridge power output unit and is used to output low-voltage, high-magnetic-moment transient electromagnetic signals.

7. A low-voltage, high-magnetic-moment transient electromagnetic emission method based on multiple parallel coils and a single H-bridge drive, characterized in that, include: The transmission control unit generates a transmission control signal, which is then electrically isolated by the isolation drive unit and sent to the power drive unit. After receiving the electrically isolated control signal, the power drive unit performs drive-level processing on it and generates a corresponding gate drive signal to be output to the H-bridge power output unit. The H-bridge power output unit responds to the gate drive signal and directly drives multiple sub-coils in the parallel coil load unit through the switching action of its power switching device, thereby realizing the forward conduction, reverse conduction, and turn-off states of the current.

8. The low-voltage high magnetic moment transient electromagnetic transmission method based on multiple parallel coils and single H-bridge drive according to claim 7, wherein the H-bridge power output unit realizes high magnetic moment transient electromagnetic output under low driving voltage without switching the coil connection mode through electronic switches.

9. A low-voltage, high-magnetic-moment transient electromagnetic emission method based on multiple parallel coils and a single H-bridge drive according to claim 7, characterized in that, The method further includes: throughout the entire conduction and turn-off phases, the plurality of sub-coils remain connected in parallel.

10. A detection device integrating a low-voltage, high-magnetic-moment transient electromagnetic emission mechanism based on multiple parallel coils and a single H-bridge drive, characterized in that, include: Electromagnetic launching mechanism, used to output high magnetic moment transient electromagnetic waves under low driving voltage; The receiving module is used to collect underground induction response signals after the electromagnetic transmitting mechanism is turned off. The data processing module is used to sample, store, and invert underground induction response signals.

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