A transient electromagnetic method primary field fast turn-off circuit and device

Abstract

This invention discloses a rapid primary field shutdown circuit and device for the electric source transient electromagnetic method. The rapid primary field shutdown circuit includes a control circuit, a power supply, an inverter circuit, a first output terminal, a second output terminal, a third output terminal, a fourth output terminal, a first switching circuit, and a second switching circuit. The inverter circuit is connected to the control circuit, the first output terminal, the second output terminal, the power supply, the third output terminal, the fourth output terminal, the first switching circuit, and the second switching circuit. This invention addresses the technical problem of the self-induced electromotive force during the turn-off time of the bipolar signal affecting the exploration results of the secondary field signal in time-domain electromagnetic exploration.

Description

Technical Field

[0001] This invention relates to the field of grounding resistance measurement technology, and in particular to a rapid turn-off circuit and device for the primary field of the transient electromagnetic method using an electrical source. Background Technology

[0002] Transient electromagnetic method, also known as time-domain electromagnetic method, involves transmitting a bipolar signal, also called a primary field signal, into the ground using a grounded source or an ungrounded loop. After the signal transmission is turned off, the receiver observes the secondary field eddy current signal using a coil or ferrite rod. The attenuation process of the secondary field is generally divided into early, middle, and late stages. In the early stage of transient electromagnetic transmission, the secondary field eddy current signal has a large amplitude and a small skin depth; while in the late stage, the secondary field eddy current signal has a small amplitude and a large skin depth. By measuring the changes in the secondary field over time at various intervals after the power outage, the geoelectric characteristics at different depths can be obtained.

[0003] When using a grounded source for signal transmission in transient electromagnetic methods, the greater the distance between electrode 1 and electrode 2 (commonly known as the AB transmitting electrodes), the longer the connecting wire becomes. This results in a larger inductive reactance in the loop formed by the long wire, a larger self-induced electromotive force when the transmitted signal is turned off, and a longer primary field turn-off time. This significantly affects the measurement of the early secondary field signal, leading to a larger blind zone in transient shallow exploration. Currently, the main approach to mitigating the impact of the primary field turn-off caused by the transient source is to use time-delay measurement to avoid the influence of the primary field on signal measurement. How to reduce the primary field turn-off time in transient electromagnetic methods remains a technical challenge for those working in the field. Summary of the Invention

[0004] This invention proposes a fast turn-off circuit for the primary field in the transient electromagnetic method with an electric source, aiming to solve the technical problem that the self-induced electromotive force of the turn-off time of the bipolar signal affects the exploration results of the secondary field signal when the time-domain electromagnetic method is used for exploration.

[0005] To achieve the above objectives, this invention proposes a fast primary field shutdown circuit for an electric source transient electromagnetic method, used to output a bipolar wave. The fast primary field shutdown circuit includes a first electrode, a second electrode, a control circuit, a power supply, an inverter circuit, a first output terminal, a second output terminal, a third output terminal, a fourth output terminal, a first switching circuit, and a second switching circuit. The inverter circuit is connected to the control circuit, the first output terminal, the second output terminal, the power supply, the third output terminal, the fourth output terminal, the first switching circuit, and the second switching circuit, respectively.

[0006] The control circuit is used to output multiple branch switching signals to control the inverter circuit to stop outputting electrical signals during the interval between the positive and negative periods of the bipolar wave transmission, and to output a first switching control signal and a second switching control signal; the first electrode and the second electrode are respectively disposed at two different locations on the ground;

[0007] The first switching circuit is used to turn on the third connection terminal and the second connection terminal of the first switching circuit according to the first switching control signal, so that a freewheeling loop is formed between the first output terminal, the third connection terminal of the first switching circuit, the second connection terminal of the first switching circuit, the first electrode and the third output terminal, so that the self-induced electromotive force of the long wire between the first output terminal and the first electrode is released quickly.

[0008] The second switching circuit is used to connect the third connection terminal and the second connection terminal of the second switching circuit according to the second switching control signal, so that a freewheeling loop is formed between the second output terminal, the third connection terminal and the second connection terminal of the second switching circuit, the second electrode and the fourth output terminal, so that the self-induced electromotive force of the long wire between the second output terminal and the second electrode is released quickly.

[0009] Optionally, the inverter circuit has a first signal transmitting terminal and a second signal transmitting terminal; the first switching circuit includes a first connection terminal, a second connection terminal, and a third connection terminal; the second switching circuit includes a first connection terminal, a second connection terminal, and a third connection terminal; the first signal transmitting terminal of the inverter circuit is connected to the first output terminal; the first signal transmitting terminal of the inverter circuit may also be selectively connected to the first connection terminal or the third connection terminal of the first switching circuit; the second signal transmitting terminal of the inverter circuit is connected to the second output terminal; the second signal transmitting terminal of the inverter circuit may also be selectively connected to the first connection terminal or the third connection terminal of the second switching circuit; the second connection terminal of the first switching circuit is connected to the third output terminal; the second connection terminal of the second switching circuit is connected to the fourth output terminal; the first electrode is connected to the first output terminal and the third output terminal respectively; and the second electrode is connected to the second output terminal and the fourth output terminal respectively.

[0010] Optionally, the control circuit is further configured to:

[0011] During the positive or negative period of the bipolar wave, multiple branch switching signals are output to control the inverter circuit to turn on, and a third switching control signal is output to control the first connection terminal of the first switching circuit to connect with the second connection terminal of the first switching circuit; and a fourth switching control signal is output to control the first connection terminal of the second switching circuit to connect with the second connection terminal of the second switching circuit.

[0012] Optionally, the inverter circuit includes a first switch circuit, a second switch circuit, a third switch circuit, and a fourth switch circuit connected in series and connected at their ends to the two ends of the power supply, respectively; it also includes a first unidirectional conduction circuit, a second unidirectional conduction circuit, a third unidirectional conduction circuit, and a fourth unidirectional conduction circuit connected in series and connected at their ends to the two ends of the power supply, respectively.

[0013] Optionally, the control circuit has a first switching control signal output terminal, a second switching control signal output terminal, a first switch control signal output terminal, a second switch control signal output terminal, a third switch control signal output terminal, and a fourth switch control signal output terminal. The first terminal of the first switch circuit is connected to the power supply, the first terminal of the second switch circuit, the output terminal of the first unidirectional conduction circuit, and the output terminal of the second unidirectional conduction circuit, respectively. The second terminal of the first switch circuit is connected to the first terminal of the fourth switch circuit, the first output terminal, the input terminal of the first unidirectional conduction circuit, the output terminal of the fourth unidirectional conduction circuit, the third terminal of the first switching circuit, and the first terminal of the second switching circuit, respectively. The controlled terminal of the first switch circuit is connected to the first switch control signal output terminal of the control circuit. The controlled terminal of the second switching circuit is connected to the second switch control signal output terminal of the control circuit; the second terminal of the third switching circuit is connected to the power supply, the second terminal of the fourth switching circuit, the input terminal of the fourth unidirectional conduction circuit, and the input terminal of the third unidirectional conduction circuit, respectively; the controlled terminal of the third switching circuit is connected to the third switch control signal output terminal of the control circuit; the input terminal of the second unidirectional conduction circuit is connected to the output terminal of the third unidirectional conduction circuit, the second output terminal, the second terminal of the second switching circuit, the first terminal of the third switching circuit, the first terminal of the first switching circuit, and the third terminal of the second switching circuit, respectively; the second terminal of the first switching circuit is connected to the third output terminal, and the second terminal of the second switching circuit is connected to the fourth output terminal.

[0014] Optionally, the first switch circuit, the second switch circuit, the third switch circuit, and the fourth switch circuit each include at least one switch, wherein the first end of the switch is the first end of the first switch circuit, the first end of the second switch circuit, the first end of the third switch circuit, or the first end of the fourth switch circuit, and the second end of the switch is the second end of the first switch circuit, the second end of the second switch circuit, the second end of the third switch circuit, or the second end of the fourth switch circuit; and the controlled end of the switch is the controlled end of the first switch circuit, the controlled end of the second switch circuit, the controlled end of the third switch circuit, or the controlled end of the fourth switch circuit.

[0015] Optionally, the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, and the fourth unidirectional conduction circuit each include at least one diode, wherein the anode of the diode is the input terminal of the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, or the fourth unidirectional conduction circuit, and the cathode of the diode is the output terminal of the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, or the fourth unidirectional conduction circuit.

[0016] Optionally, the first switching circuit and the second switching circuit each include at least one switching switch, wherein the first end of the switching switch is the first end of the first switching circuit or the first end of the second switching circuit, the second end of the switching switch is the second end of the first switching circuit or the second switching circuit, and the third end of the switching switch is the third end of the first switching circuit or the third end of the second switching circuit.

[0017] To achieve the above objectives, the present invention also proposes a fast primary field shutdown device using an electric source transient electromagnetic method, wherein the fast primary field shutdown device using an electric source transient electromagnetic method includes the electric source transient electromagnetic method fast primary field shutdown circuit as described above.

[0018] Optionally, the transient electromagnetic method primary field fast shutdown device further includes a first electrode and a second electrode. The first electrode is connected to the first output terminal and the third output terminal of the transient electromagnetic method primary field fast shutdown circuit, respectively, and the second electrode is connected to the second output terminal and the fourth output terminal of the transient electromagnetic method primary field fast shutdown circuit, respectively.

[0019] This invention solves the technical problem of the influence of the self-induced electromotive force during the turn-off time of the bipolar signal on the exploration results of the secondary field signal during the positive and negative period transmission intervals of the bipolar wave. This is achieved by outputting multiple branch switching signals during the positive and negative period transmission intervals of the bipolar wave, controlling the inverter circuit to stop outputting electrical signals, and outputting a first switching control signal to connect the third and second connection terminals of the first switching circuit. This forms a freewheeling loop between the first output terminal, the third and second connection terminals of the first switching circuit, the first electrode, and the third output terminal, allowing the self-induced electromotive force of the long wire between the first output terminal and the first electrode to be released rapidly. Simultaneously, a second switching control signal connects the third and second connection terminals of the second switching circuit, forming a freewheeling loop between the second output terminal, the third and second connection terminals of the second switching circuit, the second electrode, and the fourth output terminal, allowing the self-induced electromotive force of the long wire between the second output terminal and the second electrode to be released rapidly. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0021] Figure 1 This is a schematic diagram of a module of a primary field fast turn-off circuit for an electric source transient electromagnetic method in one embodiment.

[0022] Figure 2 This is a waveform diagram of a bipolar wave emitted by a primary field fast turn-off circuit of an electric source transient electromagnetic method in one embodiment.

[0023] Figure 3 This is a circuit diagram of a primary field fast turn-off circuit for an electric source transient electromagnetic method in one embodiment.

[0024] Figure 4 This is a schematic diagram of a module of a primary field rapid shutdown device for an electric source transient electromagnetic method in one embodiment. Detailed Implementation

[0025] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0026] To address the technical problem of the self-induced electromotive force during the turn-off time of the bipolar signal affecting the exploration results of the secondary field signal in time-domain electromagnetic exploration, this invention proposes a rapid turn-off circuit and electronic device for the primary field in an electric source transient electromagnetic method.

[0027] In one embodiment, such as Figure 1 As shown, an electric source transient electromagnetic method primary field fast turn-off circuit is used to output a bipolar wave. The electric source transient electromagnetic method primary field fast turn-off circuit includes a control circuit 50, a power supply BT, an inverter circuit 20, a first output terminal K1, a second output terminal K2, a third output terminal K3, a fourth output terminal K4, a first switching circuit 30, a first electrode, a second electrode, and a second switching circuit 40. The inverter circuit is connected to the control circuit 50, the first output terminal K1, the second output terminal K2, the power supply BT, the third output terminal K3, the fourth output terminal K4, the first switching circuit 30, and the second switching circuit 40. The first electrode is connected to the first output terminal and the third output terminal, and the second electrode is connected to the fourth output terminal and the second output terminal.

[0028] The control circuit is used to output multiple branch switching signals during the positive and negative period transmission intervals of the bipolar wave to control the inverter circuit to stop outputting electrical signals, and to output a first switching control signal and a second switching control signal. The first electrode and the second electrode are respectively disposed at two different locations on the ground. The first switching circuit conducts its third connection terminal and its second connection terminal according to the first switching control signal, so that a freewheeling loop is formed between the first output terminal, the third connection terminal and the second connection terminal of the first switching circuit, the first electrode and the third output terminal, so that the self-induced electromotive force of the long wire between the first output terminal and the first electrode is released quickly. The second switching circuit conducts its third connection terminal and its second connection terminal according to the second switching control signal, so that a freewheeling loop is formed between the second output terminal, the third connection terminal and the second connection terminal of the second switching circuit, the second electrode and the fourth output terminal, so that the self-induced electromotive force of the long wire between the second output terminal and the second electrode is released quickly.

[0029] In the above embodiments, the present invention controls the inverter circuit to stop outputting electrical signals by outputting multiple branch switching signals during the positive and negative period transmission intervals of the bipolar wave, and outputs multiple switching control signals to control the second and third connection terminals of the first switching circuit 30 to conduct, and to control the second and third connection terminals of the second switching circuit 40 to conduct, thereby forming a freewheeling loop between the first output terminal, the third connection terminal of the first switching circuit, the second connection terminal of the first switching circuit, the first electrode, and the third output terminal, and a freewheeling loop between the second output terminal, the third connection terminal of the second switching circuit, the second connection terminal of the second switching circuit, the second electrode, and the fourth output terminal. This allows for the rapid release of the self-induced electromotive force caused by the long conductor, thus solving the technical problem of the self-induced electromotive force during the turn-off time of the bipolar signal affecting the exploration results of the secondary field signal in time-domain electromagnetic exploration. The above solution can greatly reduce the influence of the self-induced electromotive force after the primary field is disconnected on the secondary field measurement, thereby improving the shallow exploration capability of the electric source transient electromagnetic instrument and reducing the shallow blind zone.

[0030] Alternatively, the above-mentioned solution can be implemented using the following circuit:

[0031] The inverter circuit has a first signal transmitting terminal and a second signal transmitting terminal. The first switching circuit includes a first connection terminal, a second connection terminal, and a third connection terminal. The second switching circuit includes a first connection terminal, a second connection terminal, and a third connection terminal. The first signal transmitting terminal of the inverter circuit is connected to the first output terminal. The first signal transmitting terminal of the inverter circuit can also be selectively connected to the first connection terminal or the third connection terminal of the first switching circuit. The second signal transmitting terminal of the inverter circuit is connected to the second output terminal. The second signal transmitting terminal of the inverter circuit can also be selectively connected to the first connection terminal or the third connection terminal of the second switching circuit. The second connection terminal of the first switching circuit is connected to the third output terminal. The second connection terminal of the second switching circuit is connected to the fourth output terminal. The first electrode is connected to the first output terminal and the third output terminal respectively. The second electrode is connected to the second output terminal and the fourth output terminal respectively.

[0032] Optionally, the control circuit 50 may also output multiple branch switching signals during the positive or negative period of the bipolar wave to control the output electrical signal of the inverter circuit 20, and output a third switching control signal to control the connection of the first connection terminal of the first switching circuit to the second connection terminal of the first switching circuit; and output a fourth switching control signal to control the connection of the first connection terminal of the second switching circuit to the second connection terminal of the second switching circuit.

[0033] Optionally, the bipolar wave includes multiple positive periods and multiple negative periods, as referenced. Figure 2 As shown, the positive periods are T1 and T5, and the negative periods are T3 and T7, which are also the primary field signals mentioned in the background art. T2, T4, T6, and T8 are the transmission and shutdown times of the positive and negative periods, which are also the times when the receiver observes the secondary field eddy current signals as described in the background art.

[0034] Optionally, the inverter circuit 20 includes a first switch circuit, a second switch circuit, a third switch circuit, and a fourth switch circuit connected in series and connected at their ends to the two ends of the power supply BT, respectively; it also includes a first unidirectional conduction circuit, a second unidirectional conduction circuit, a third unidirectional conduction circuit, and a fourth unidirectional conduction circuit connected in series and connected at their ends to the two ends of the power supply BT, respectively.

[0035] Optionally, refer to Figure 3As shown, the control circuit 50 has a first switching control signal output terminal 5, a second switching control signal output terminal 6, a first switch control signal output terminal 1, a second switch control signal output terminal 2, a third switch control signal output terminal 3, and a fourth switch control signal output terminal 4. The first terminal of the first switch circuit is connected to the power supply BT, the first terminal of the second switch circuit, the output terminal of the first unidirectional conduction circuit, and the output terminal of the second unidirectional conduction circuit, respectively. The second terminal of the first switch circuit is connected to the first terminal of the fourth switch circuit, the first output terminal K1, the input terminal of the first unidirectional conduction circuit, and the output terminal of the fourth unidirectional conduction circuit, respectively. The third terminal of the first switching circuit is connected to the first terminal of the second switching circuit 40. The controlled terminal of the first switch circuit is connected to the first switch control signal output terminal 1 of the control circuit 50. The controlled terminal of the second switch circuit is connected to the second switch control signal output terminal 2 of the control circuit 50. The second terminal of the third switch circuit is connected to the power supply BT. BT, the second terminal of the fourth switching circuit, the input terminal of the fourth unidirectional conduction circuit, and the input terminal of the third unidirectional conduction circuit are connected; the controlled terminal of the third switching circuit is connected to the third switch control signal output terminal 3 of the control circuit 50; the controlled terminal of the fourth switching circuit is connected to the fourth switch control signal output terminal 4 of the control circuit 50; the controlled terminal of the first switching circuit 30 is connected to the first switching control signal output terminal 5 of the control circuit 50; the controlled terminal of the second switching circuit 40 is connected to the second switching control signal output terminal 6 of the control circuit 50; the input terminal of the second unidirectional conduction circuit is connected to the output terminal of the third unidirectional conduction circuit, the second output terminal K2, the second terminal of the second switching circuit, the first terminal of the third switching circuit, the first terminal of the first switching circuit, and the third terminal of the second switching circuit 40, respectively; the second terminal of the first switching circuit is connected to the third output terminal K3, and the second terminal of the second switching circuit is connected to the fourth output terminal K4.

[0036] Optionally, the first switch circuit, the second switch circuit, the third switch circuit, and the fourth switch circuit each include at least one switch, wherein the first end of the switch is the first end of the first switch circuit, the first end of the second switch circuit, the first end of the third switch circuit, or the first end of the fourth switch circuit, and the second end of the switch is the second end of the first switch circuit, the second end of the second switch circuit, the second end of the third switch circuit, or the second end of the fourth switch circuit; and the controlled end of the switch is the controlled end of the first switch circuit, the controlled end of the second switch circuit, the controlled end of the third switch circuit, or the controlled end of the fourth switch circuit.

[0037] The four switches together form a power inverter bridge (H), responsible for inverting the power supply BT to output a DC power supply. It should be noted that programmable power switches are preferable for better control.

[0038] Optionally, refer to Figure 3 As shown, the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, and the fourth unidirectional conduction circuit each include at least one diode D1-D4. The anode of the diode is the input terminal of the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, or the fourth unidirectional conduction circuit, and the cathode of the diode is the output terminal of the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, or the fourth unidirectional conduction circuit.

[0039] The diode provides a reverse freewheeling circuit when switches S1, S2, S3, and S4 are turned off, thus constituting the switches of inverter circuit 20. It should be noted that the aforementioned diode can be a freewheeling diode.

[0040] Optionally, the first switching circuit 30 and the second switching circuit 40 each include at least one switching switch, wherein the first end of the switching switch is the first end of the first switching circuit 30 or the first end of the second switching circuit 40, the second end of the switching switch is the second end of the first switching circuit 30 or the second switching circuit 40, and the third end of the switching switch is the third end of the first switching circuit 30 or the third end of the second switching circuit 40.

[0041] The first switching circuit 30 and the second switching circuit 40 are responsible for completing the parallel connection and reverse series connection of the first circuit 10 and the second circuit. It should be noted that the switching switches S5 and S6 can be implemented using programmable power switches, including but not limited to IGBTs, power MOSFETs, etc.

[0042] The following combination Figure 1 , Figure 2 , Figure 3 as well as Figure 4 Explanation of the working principle of this invention:

[0043] Among them, loop one starts from J1 and connects L1, electrode 1, L5, electrode 2, L2, all the way to J2. This loop is the power supply loop. L3 and L4 are connected to the transmitter inverter through J3 and J4 to form loop two with L1 and L2.

[0044] During cycle T1, programmable power switches S1 and S3 are closed and conducting, while S2 and S4 are open. Contacts 2 and 1 in programmable power switches S5 and S6 are connected. At this time, J1 and J3 are positive, and J2 and J4 are negative. Current flows from J1 and J3 to J2 and J4. Circuit 1 and Circuit 2 are connected in parallel to supply positive power to the ground, forming a primary excitation field.

[0045] During cycle T2, all programmable power switches S1, S3, S2, and S4 are disconnected. Because the circuit is an inductive load, the current cannot change abruptly. Both circuits generate self-induced electromotive forces in the same direction. At this time, contacts 2 and 3 in programmable power switches S5 and S6 are turned on. Circuit 1 and Circuit 2 are connected in anti-series parallel, and the self-induced electromotive forces of the two circuits cancel each other out, greatly reducing the impact of the primary field shutdown on the secondary field observation during cycle T2.

[0046] During cycle T3, programmable power switches S2 and S4 are closed and conducting, while S1 and S3 are open. Contacts 2 and 1 in programmable power switches S5 and S6 are connected. At this time, J2 and J4 are positive, and J1 and J3 are negative. Current flows from J2 and J4 to J1 and J3. Circuit 1 and Circuit 2 are connected in parallel to supply power to the ground in reverse, forming a primary excitation field.

[0047] During cycle T4, all programmable power switches S1, S3, S2, and S4 are disconnected. Because the circuit is an inductive load, the current cannot change abruptly. Both circuits generate self-induced electromotive forces in the same direction. At this time, contacts 2 and 3 in programmable power switches S5 and S6 are turned on. Circuit 1 and Circuit 2 are connected in anti-series parallel, and the self-induced electromotive forces of the two circuits cancel each other out, greatly reducing the impact of the primary field shutdown on the secondary field observation during cycle T4.

[0048] T5, T6, T7, and T8 are repetitions of T1, T2, T3, and T4 in the second cycle, and so on. Therefore, the above scheme solves the technical problem of the self-induced electromotive force during the turn-off time of the bipolar signal affecting the exploration results of the secondary field signal in time-domain electromagnetic exploration. It can greatly reduce the influence of the self-induced electromotive force after the primary field is disconnected on the secondary field measurement, thereby improving the shallow exploration capability of the electric source transient electromagnetic instrument and reducing the shallow blind zone.

[0049] To address the aforementioned problems, this invention also proposes a rapid primary field shutdown device using an electric source transient electromagnetic method, wherein the rapid primary field shutdown device using an electric source transient electromagnetic method includes the rapid primary field shutdown circuit described above.

[0050] It should be noted that, since the fast turn-off device for the primary field using the transient electromagnetic method of the electric source in this application includes all embodiments of the fast turn-off circuit for the primary field using the transient electromagnetic method of the electric source, all schemes of the fast turn-off circuit for the primary field using the transient electromagnetic method of the electric source can also be realized using the fast turn-off device for the primary field using the transient electromagnetic method of the electric source, and it has the same beneficial effects, which will not be repeated here.

[0051] Optionally, such as Figure 4 As shown, the electric source transient electromagnetic method primary field fast shutdown device further includes a first electrode and a second electrode. The first electrode is connected to the first output terminal and the third output terminal K3 of the electric source transient electromagnetic method primary field fast shutdown circuit, respectively. The second electrode is connected to the second output terminal and the fourth output terminal of the electric source transient electromagnetic method primary field fast shutdown circuit, respectively.

[0052] The first and second electrodes are connected to the Earth's surface for geological exploration.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A fast turn-off circuit for a primary field using an electric source transient electromagnetic method, used to output a bipolar wave, characterized in that, The transient electromagnetic method primary field fast shutdown circuit of the electric source includes a first electrode, a second electrode, a control circuit, a power supply, an inverter circuit, a first output terminal, a second output terminal, a third output terminal, a fourth output terminal, a first switching circuit, and a second switching circuit. The inverter circuit is connected to the control circuit, the first output terminal, the second output terminal, the power supply, the third output terminal, the fourth output terminal, the first switching circuit, and the second switching circuit. The first electrode is connected to the first output terminal and the third output terminal, and the second electrode is connected to the fourth output terminal and the second output terminal. The control circuit is used to output multiple branch switching signals to control the inverter circuit to stop outputting electrical signals during the interval between the positive and negative periods of the bipolar wave transmission, and to output a first switching control signal and a second switching control signal; the first electrode and the second electrode are respectively disposed at two different locations on the ground; The first switching circuit is used to turn on the third connection terminal and the second connection terminal of the first switching circuit according to the first switching control signal, so that a freewheeling loop is formed between the first output terminal, the third connection terminal of the first switching circuit, the second connection terminal of the first switching circuit, the first electrode and the third output terminal, so that the self-induced electromotive force of the long wire between the first output terminal and the first electrode is released quickly. The second switching circuit is used to turn on the third connection terminal and the second connection terminal of the second switching circuit according to the second switching control signal, so that a freewheeling loop is formed between the second output terminal, the third connection terminal of the second switching circuit, the second connection terminal of the second switching circuit, the second electrode and the fourth output terminal, so that the self-induced electromotive force of the long wire between the second output terminal and the second electrode is released quickly. The inverter circuit has a first signal transmitting terminal and a second signal transmitting terminal. The first switching circuit includes a first connection terminal, a second connection terminal, and a third connection terminal. The second switching circuit includes a first connection terminal, a second connection terminal, and a third connection terminal. The first signal transmitting terminal of the inverter circuit is connected to the first output terminal. The first signal transmitting terminal of the inverter circuit can also be selectively connected to the first connection terminal or the third connection terminal of the first switching circuit. The second signal transmitting terminal of the inverter circuit is connected to the second output terminal. The second signal transmitting terminal of the inverter circuit can also be selectively connected to the first connection terminal or the third connection terminal of the second switching circuit. The second connection terminal of the first switching circuit is connected to the third output terminal. The second connection terminal of the second switching circuit is connected to the fourth output terminal. The first electrode is connected to the first output terminal and the third output terminal respectively. The second electrode is connected to the second output terminal and the fourth output terminal respectively.

2. The fast turn-off circuit of the primary field using the transient electromagnetic method of the electrical source as described in claim 1, characterized in that, The control circuit is also used for: During the positive or negative period of the bipolar wave, multiple branch switching signals are output to control the inverter circuit to output electrical signals, and a third switching control signal is output to control the first connection terminal of the first switching circuit to connect with the second connection terminal of the first switching circuit; and a fourth switching control signal is output to control the first connection terminal of the second switching circuit to connect with the second connection terminal of the second switching circuit.

3. The fast turn-off circuit for the primary field using the transient electromagnetic method of the electrical source as described in claim 1, characterized in that, The inverter circuit includes a first switch circuit, a second switch circuit, a third switch circuit, and a fourth switch circuit connected in series and connected at their ends to the two ends of the power supply, respectively; it also includes a first unidirectional conduction circuit, a second unidirectional conduction circuit, a third unidirectional conduction circuit, and a fourth unidirectional conduction circuit connected in series and connected at their ends to the two ends of the power supply, respectively.

4. The fast turn-off circuit of the primary field using the transient electromagnetic method of the electrical source as described in claim 3, characterized in that, The control circuit has a first switching control signal output terminal, a second switching control signal output terminal, a first switch control signal output terminal, a second switch control signal output terminal, a third switch control signal output terminal, and a fourth switch control signal output terminal. The first terminal of the first switch circuit is connected to the power supply, the first terminal of the second switch circuit, the output terminal of the first unidirectional conduction circuit, and the output terminal of the second unidirectional conduction circuit, respectively. The second terminal of the first switch circuit is connected to the first terminal of the fourth switch circuit, the first output terminal, the input terminal of the first unidirectional conduction circuit, the output terminal of the fourth unidirectional conduction circuit, the third terminal of the first switching circuit, and the first terminal of the second switching circuit, respectively. The controlled terminal of the first switch circuit is connected to the first switch control signal output terminal of the control circuit; the controlled terminal of the second switch circuit is connected to the second switch control signal output terminal of the control circuit; the second terminal of the third switch circuit is connected to the power supply, the first terminal of the second switch circuit, the first terminal of the third switch circuit, and the first terminal of the fourth switch circuit, respectively. The source, the second terminal of the fourth switching circuit, the input terminal of the fourth unidirectional conduction circuit, and the input terminal of the third unidirectional conduction circuit are connected; the controlled terminal of the third switching circuit is connected to the third switch control signal output terminal of the control circuit; the input terminal of the second unidirectional conduction circuit is connected to the output terminal of the third unidirectional conduction circuit, the second output terminal, the second terminal of the second switching circuit, the first terminal of the third switching circuit, the first terminal of the first switching circuit, and the third terminal of the second switching circuit; the second terminal of the first switching circuit is connected to the third output terminal, and the second terminal of the second switching circuit is connected to the fourth output terminal; the controlled terminal of the fourth switching circuit is connected to the fourth switch control signal output terminal of the control circuit; the controlled terminal of the first switching circuit is connected to the first switching control signal output terminal of the control circuit; and the controlled terminal of the second switching circuit is connected to the second switching control signal output terminal of the control circuit.

5. The fast turn-off circuit of the primary field using the transient electromagnetic method of the electrical source as described in claim 3, characterized in that, The first switch circuit, the second switch circuit, the third switch circuit, and the fourth switch circuit each include at least one switch. The first end of the switch is the first end of the first switch circuit, the first end of the second switch circuit, the first end of the third switch circuit, or the first end of the fourth switch circuit. The second end of the switch is the second end of the first switch circuit, the second end of the second switch circuit, the second end of the third switch circuit, or the second end of the fourth switch circuit. The controlled end of the switch is the controlled end of the first switch circuit, the controlled end of the second switch circuit, the controlled end of the third switch circuit, or the controlled end of the fourth switch circuit.

6. The fast turn-off circuit of the primary field using the transient electromagnetic method of the electrical source as described in claim 3, characterized in that, The first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, and the fourth unidirectional conduction circuit each include at least one diode. The anode of the diode is the input terminal of the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, or the fourth unidirectional conduction circuit. The cathode of the diode is the output terminal of the first unidirectional conduction circuit, the second unidirectional conduction circuit, the third unidirectional conduction circuit, or the fourth unidirectional conduction circuit.

7. The transient electromagnetic method primary field fast turn-off circuit for an electrical source as described in any one of claims 1-6, characterized in that, The first switching circuit and the second switching circuit each include at least one switching switch, the first end of the switching switch being the first end of the first switching circuit or the first end of the second switching circuit, the second end of the switching switch being the second end of the first switching circuit or the second switching circuit, and the third end of the switching switch being the third end of the first switching circuit or the third end of the second switching circuit.

8. A device for rapid primary field shutdown using transient electromagnetic method with an electrical source, characterized in that, The device for rapid primary field shutdown using transient electromagnetic method with an electric source includes the rapid primary field shutdown circuit with transient electromagnetic method as described in any one of claims 1-7.

9. The transient electromagnetic method primary field rapid turn-off device for an electrical source as described in claim 8, characterized in that, The transient electromagnetic method primary field fast shutdown device for the electric source further includes a first electrode and a second electrode. The first electrode is connected to the first output terminal and the third output terminal of the transient electromagnetic method primary field fast shutdown circuit for the electric source, respectively. The second electrode is connected to the second output terminal and the fourth output terminal of the transient electromagnetic method primary field fast shutdown circuit for the electric source, respectively.

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