Overhead ground wire grounding detection system

Abstract

The application provides an overhead ground wire grounding detection system, which comprises a power module, a direct current voltage boosting module, an inverter module, a first filter module, a second filter module, a coupling loading unit, a control transmission module and an acquisition unit; the output end of the power module is connected to the input end of the direct current voltage boosting module; the output end of the direct current voltage boosting module is connected to the input end of the inverter module through the first filter module; the output end of the inverter module is connected to the input end of the second filter module; the output end of the second filter module is connected to the input end of the coupling loading unit; the coupling loading module loads a test voltage on the overhead ground wire through electromagnetic induction; the acquisition unit is used for acquiring the voltage and current of the overhead ground wire and outputting to the control transmission module; the control transmission module determines the grounding resistance value of the overhead ground wire according to the voltage and current output by the acquisition unit, can load a stable and reliable test voltage on the overhead ground wire, and ensures the accuracy of the monitoring of the grounding resistance of the overhead ground wire.

Description

Technical Field

[0001] This invention relates to a power detection system, and more particularly to an overhead ground wire grounding detection system. Background Technology

[0002] There are numerous overhead ground wires in power transmission lines, which are used to ground the transmission towers. The overhead ground wires are used to protect the towers from lightning. The grounding performance of the overhead ground wires will seriously affect the power supply stability of the overhead transmission lines.

[0003] In existing technologies, research on grounding monitoring of overhead ground wires is based on the grounding resistance of the overhead ground wire. When the grounding resistance exceeds a set value, it indicates a grounding fault; when it is less than the set value, it indicates normal grounding. There are two existing methods for measuring the grounding resistance of overhead ground wires: one is by workers using measuring instruments, which is time-consuming, labor-intensive, inefficient, and prone to missed detections. Therefore, a second method, online monitoring, has been proposed. Online monitoring of overhead ground wire grounding resistance involves injecting a detection signal into the overhead ground wire, then using current transformers and voltage transformers to obtain the current flowing through the overhead ground wire and the voltage to ground, and finally calculating the grounding resistance using Ohm's law. While this method solves the technical defects of the first method, existing online monitoring systems still have shortcomings in two main aspects:

[0004] First, the existing methods are basically based on the principle of electromagnetic induction to couple and load the test voltage. However, the contradiction of the existing coupling loading method is that loading with existing instruments is complex and costly. If the cost is reduced, the power supply requirements are high. If instruments on the market are not used, the stability is poor. On the other hand, when there is lightning current in the overhead ground wire, it will cause serious safety hazards to the instrument itself or the test voltage loading circuit.

[0005] Therefore, in order to solve the above-mentioned technical problems, it is urgent to propose a new technical approach. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide an overhead ground wire grounding detection system that can apply a stable and reliable test voltage to the overhead ground wire, ensuring the accuracy of monitoring the grounding resistance of the overhead ground wire, providing accurate and real-time data support for subsequent processing, and the entire system is stable and reliable, and is more cost-effective than existing instruments, and can effectively prevent the impact of lightning current on the front-end loading control circuit, ensuring stability.

[0007] The present invention provides an overhead ground wire grounding detection system, comprising a power supply module, a DC boost module, an inverter module, a first filter module, a second filter module, a coupling loading unit, a control transmission module, and a data acquisition unit;

[0008] The power supply module has its output terminal connected to the input terminal of the DC boost module. The output terminal of the DC boost module is connected to the input terminal of the inverter module through the first filter module. The output terminal of the inverter module is connected to the input terminal of the second filter module. The output terminal of the second filter module is connected to the input terminal of the coupling loading unit. The coupling loading module applies a test voltage to the overhead ground wire through electromagnetic induction.

[0009] The acquisition unit is used to acquire the voltage and current of the overhead ground wire and output them to the control transmission module. The control transmission module determines the grounding resistance value of the overhead ground wire based on the voltage and current output by the acquisition unit.

[0010] Furthermore, the DC boost module includes resistors R1, R2, R3, and R4, inductor L1, capacitors C1, C2, and C3, transistors T1 and T2, NMOS transistor Q1, diode D1, operational amplifier U1, and control chip U1.

[0011] One end of resistor R1 is connected to one end of inductor L1. The common connection point between resistor R1 and inductor L1 serves as the input terminal of the DC-DC boost module. The anode of diode D1 is connected to the other end of inductor L1, and the cathode of diode D1 is grounded through capacitor C2. The cathode of diode D2 serves as the output terminal of the DC-DC boost module. The other end of resistor R1 is connected to the collector of transistor T1. The emitter of transistor T1 is connected to the emitter of transistor T2. The collector of transistor T2 is grounded. The emitter of transistor T1 is connected to the gate of NMOS transistor Q1 through resistor R2. Transistors T1 and T2... The base of the transistor is connected to the control output terminal of the control chip U2 via capacitor C3. The drain of the NMOS transistor Q1 is connected to the positive terminal of the diode D1, and the source of the NMOS transistor Q1 is grounded. The other end of the resistor R3 is connected to the negative terminal of the diode D1, and the other end of the resistor R3 is grounded via resistor R4. The common connection point of resistors R4 and R3 is connected to the non-inverting input of the operational amplifier U1. The inverting input of the operational amplifier U1 is directly connected to the output terminal of the operational amplifier U1. The output terminal of the operational amplifier U1 is connected to the detection input terminal of the control chip U2. Among them, transistor T2 is a P-type transistor, and the control chip U2 is an L6562 chip.

[0012] Furthermore, the inverter module includes an inverter, an inverter drive circuit, and a transformer;

[0013] The inverter's power input terminal is connected to the output terminal of the DC boost module, the inverter's power output terminal is connected to the primary winding of the transformer, the transformer's secondary winding is connected to the input terminal of the coupling loading module, the coupling loading module, and the control output terminal of the inverter drive circuit are connected to the control input terminal of the inverter, which in turn is connected to the control transmission module.

[0014] Furthermore, the coupling loading unit includes a coupling circuit and a lightning protection circuit;

[0015] The coupling circuit includes coupling coil L3, coupling coil L4, resistor R11, and capacitor C5; the same-name terminal of coupling coil L3 is connected to the output terminal of the second filter module as the input terminal of the coupling loading unit, and the opposite-name terminal of coupling coil L3 is grounded; the same-name terminal of coupling coil L4 is connected to the opposite-name terminal of coupling coil L4 through resistor R11 and capacitor C5 in parallel; coupling coil L3 and coupling coil L4 form a transformer structure and coupling coil L4 is sleeved on the overhead ground wire;

[0016] The lightning protection circuit includes a relay, resistors R5, R6, R7, R8, R9, R10, R12, R13, diodes D2, D3, and D4, a silicon controlled rectifier Q2, a transistor T3, optocouplers G1 and G2, a Zener diode ZD1, and a capacitor C4.

[0017] One end of resistor R9 is connected to the same-name terminal of coupling coil L3. The other end of resistor R9 is grounded after being connected in parallel with resistor R10 and capacitor C4. The common connection point of resistors R9 and R10 is connected to the negative terminal of Zener diode ZD1. The positive terminal of Zener diode ZD1 is connected to the positive terminal of LED of optocoupler G1 through resistor R8. The negative terminal of LED of optocoupler G1 is connected to the positive terminal of LED of optocoupler G2. The negative terminal of LED of optocoupler G2 is grounded. The collector of phototransistor of optocoupler G2 is connected to the negative terminal of diode D4. The positive terminal of diode D4 is connected to the detection input terminal of control transmission module. The emitter of phototransistor of optocoupler G2 is grounded. The emitter of phototransistor of optocoupler G1 is connected to... Resistor R12 is grounded. The collector of the phototransistor in optocoupler G1 is connected to the output of the DC-DC boost module through resistor R7. The emitter of optocoupler G1 is connected to the control electrode of thyristor Q2 through resistor R13. The negative terminal of thyristor Q2 is grounded. The positive terminal of thyristor Q2 is connected to one end of the excitation coil J1 of the relay. The other end of the excitation coil J2 of relay J1 is connected to the output of the DC-DC boost module through resistor R5. The positive terminal of diode D3 is connected to the positive terminal of thyristor Q2. The negative terminal of diode D3 is connected to the common connection point between the excitation coil J1 of the relay and resistor R5. One end of the normally open switch K1 of the relay is connected to the same-name terminal of coupling coil L3. The other end of the normally open switch K1 of the relay is grounded.

[0018] The collector of transistor T3 is connected to the output terminal of the DC boost circuit through resistor R6. The emitter of transistor T3 is grounded, the base of transistor T3 is connected to the negative terminal of diode D2, and the positive terminal of diode D2 is connected to the control output terminal of the control transmission module.

[0019] Furthermore, the control transmission module includes a controller, a wireless communication module, and a positioning circuit;

[0020] The controller is connected to the remote monitoring host via a wireless communication module and to the positioning circuit. The detection input terminal of the controller is connected to the positive terminal of diode D4, the control output terminal of the controller is connected to the positive terminal of diode D2, and the sampling input terminal of the controller is connected to the output terminal of the acquisition unit.

[0021] Furthermore, the acquisition unit includes a voltage transformer, a current transformer, a first bandpass filter, a second bandpass filter, a voltage rectifier circuit, a current rectifier circuit, a voltage sampling circuit, a current sampling circuit, and a dual-channel analog-to-digital converter.

[0022] The output terminal of the voltage transformer is connected to the input terminal of the first bandpass filter, the output terminal of the first bandpass filter is connected to the input terminal of the voltage rectifier circuit, the output terminal of the voltage rectifier circuit is connected to the input terminal of the voltage sampling circuit, and the output terminal of the voltage sampling circuit is connected to the input terminal of the voltage sampling channel of the dual-channel analog-to-digital converter.

[0023] The output of the current transformer is connected to the input of the second bandpass filter. The output of the second bandpass filter is connected to the input of the current rectifier circuit. The output of the current rectifier circuit is connected to the input of the current sampling circuit. The output of the current sampling circuit is connected to the input of the current sampling channel of the dual-channel analog-to-digital converter. The output of the voltage sampling channel and the output of the current sampling channel of the dual-channel analog-to-digital converter are connected to the sampling input of the controller.

[0024] Furthermore, the power module includes a power voltage transformer, a rectifier circuit, a lithium battery, a battery management circuit, and a voltage regulator circuit.

[0025] The power supply voltage transformer is installed on the transmission line. The output terminal of the power supply voltage transformer is connected to the input terminal of the rectifier circuit. The output terminal of the rectifier circuit is connected to the input terminal of the RC filter circuit. The output terminal of the RC filter circuit is connected to the output terminal of the voltage regulator circuit, which outputs 5V DC power. The power input terminal of the battery management circuit is connected to the output terminal of the RC filter circuit. The output terminal of the battery management circuit is connected to the lithium battery. The output terminal of the lithium battery supplies power to the control transmission module and the DC boost circuit.

[0026] The beneficial effects of this invention are as follows: This invention enables the application of a stable and reliable test voltage to the overhead ground wire, ensuring the accuracy of monitoring the grounding resistance of the overhead ground wire and providing accurate and real-time data support for subsequent processing. Moreover, the entire system is stable and reliable, and its cost is lower than that of existing instruments. Furthermore, it can effectively prevent the impact of lightning current on the front-end loading control circuit, ensuring stability. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] Figure 2 This is a schematic diagram of the DC boost circuit of the present invention.

[0030] Figure 3 This is a schematic diagram of the coupling loading unit of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below:

[0032] The present invention provides an overhead ground wire grounding detection system, comprising a power supply module, a DC boost module, an inverter module, a first filter module, a second filter module, a coupling loading unit, a control transmission module, and a data acquisition unit; wherein the first filter module and the second filter module adopt π-type filters composed of LC circuits;

[0033] The power supply module has its output terminal connected to the input terminal of the DC boost module. The output terminal of the DC boost module is connected to the input terminal of the inverter module through the first filter module. The output terminal of the inverter module is connected to the input terminal of the second filter module. The output terminal of the second filter module is connected to the input terminal of the coupling loading unit. The coupling loading module applies a test voltage to the overhead ground wire through electromagnetic induction.

[0034] The acquisition unit is used to acquire the voltage and current of the overhead ground wire and output them to the control transmission module. The control transmission module determines the grounding resistance value of the overhead ground wire based on the voltage and current output by the acquisition unit. Through the above structure, a stable and reliable test voltage can be applied to the overhead ground wire, ensuring the accuracy of monitoring the grounding resistance of the overhead ground wire and providing accurate and real-time data support for subsequent processing. Moreover, the entire system is stable and reliable, and its cost is lower than that of existing instruments. It can also effectively prevent the impact of lightning current on the front-end loading control circuit, ensuring stability.

[0035] In this embodiment, the DC boost module includes resistors R1, R2, R3, and R4, inductor L1, capacitors C1, C2, and C3, transistors T1 and T2, NMOS transistor Q1, diode D1, operational amplifier U1, and control chip U1.

[0036] One end of resistor R1 is connected to one end of inductor L1. The common connection point between resistor R1 and inductor L1 serves as the input terminal of the DC-DC boost module. The anode of diode D1 is connected to the other end of inductor L1, and the cathode of diode D1 is grounded through capacitor C2. The cathode of diode D2 serves as the output terminal of the DC-DC boost module. The other end of resistor R1 is connected to the collector of transistor T1. The emitter of transistor T1 is connected to the emitter of transistor T2. The collector of transistor T2 is grounded. The emitter of transistor T1 is connected to the gate of NMOS transistor Q1 through resistor R2. The bases of transistors T1 and T2 are connected and connected to the control output terminal of control chip U2 through capacitor C3. The drain of NMOS transistor Q1 is connected to the anode of diode D1, and the source of NMOS transistor Q1 is grounded. The other end of resistor R3 is connected to diode D1. The negative terminal of resistor R3 is connected to ground via resistor R4. The common connection point of resistors R4 and R3 is connected to the non-inverting input of operational amplifier U1. The inverting input of operational amplifier U1 is directly connected to the output of operational amplifier U1. The output of operational amplifier U1 is connected to the detection input of control chip U2. Transistor T2 is a P-type transistor, and control chip U2 is an L6562 chip. In the above structure, inductor L1, diode D1, and NMOS transistor Q1 form a typical PFC DC boost circuit and output 12V DC. Resistors R3 and R4 are used for sampling feedback. U1 forms a voltage follower, which can stabilize the sampling voltage and provide good protection for control chip U2. T1 and T2 form a totem pole drive circuit to ensure the drive control capability of NMOS transistor Q1. Control chip U2 uses L6562 chip.

[0037] In this embodiment, the inverter module includes an inverter, an inverter drive circuit, and a transformer;

[0038] The inverter's power input is connected to the output of the DC boost module, and the inverter's power output is connected to the primary winding of the transformer. The secondary winding of the transformer is connected to the input of the coupling loading module. The control output of the inverter drive circuit is connected to the control input of the inverter, and the control input of the inverter drive circuit is connected to the control transmission module. The inverter converts 12V DC to AC at a controllable frequency, which is then boosted to 36V by the transformer and applied to the overhead ground wire via the coupling loading unit. Through the inverter module and the DC boost circuit, the stability of the test voltage is effectively improved, and the applicability is enhanced. The inverter drive circuit uses an existing circuit and will not be described in detail here.

[0039] In this embodiment, the coupling loading unit includes a coupling circuit and a lightning protection circuit;

[0040] The coupling circuit includes coupling coil L3, coupling coil L4, resistor R11, and capacitor C5; the same-name terminal of coupling coil L3 is connected to the output terminal of the second filter module as the input terminal of the coupling loading unit, and the opposite-name terminal of coupling coil L3 is grounded; the same-name terminal of coupling coil L4 is connected to the opposite-name terminal of coupling coil L4 through resistor R11 and capacitor C5 in parallel; coupling coil L3 and coupling coil L4 form a transformer structure and coupling coil L4 is sleeved on the overhead ground wire;

[0041] The lightning protection circuit includes a relay, resistors R5, R6, R7, R8, R9, R10, R12, R13, diodes D2, D3, and D4, a silicon controlled rectifier Q2, a transistor T3, optocouplers G1 and G2, a Zener diode ZD1, and a capacitor C4.

[0042] One end of resistor R9 is connected to the same-name terminal of coupling coil L3. The other end of resistor R9 is grounded after being connected in parallel with resistor R10 and capacitor C4. The common connection point of resistors R9 and R10 is connected to the negative terminal of Zener diode ZD1. The positive terminal of Zener diode ZD1 is connected to the positive terminal of LED of optocoupler G1 through resistor R8. The negative terminal of LED of optocoupler G1 is connected to the positive terminal of LED of optocoupler G2. The negative terminal of LED of optocoupler G2 is grounded. The collector of phototransistor of optocoupler G2 is connected to the negative terminal of diode D4. The positive terminal of diode D4 is connected to the detection input terminal of control transmission module. The emitter of phototransistor of optocoupler G2 is grounded. The emitter of phototransistor of optocoupler G1 is connected to... Resistor R12 is grounded. The collector of the phototransistor in optocoupler G1 is connected to the output of the DC-DC boost module through resistor R7. The emitter of optocoupler G1 is connected to the control electrode of thyristor Q2 through resistor R13. The negative terminal of thyristor Q2 is grounded. The positive terminal of thyristor Q2 is connected to one end of the excitation coil J1 of the relay. The other end of the excitation coil J2 of relay J1 is connected to the output of the DC-DC boost module through resistor R5. The positive terminal of diode D3 is connected to the positive terminal of thyristor Q2. The negative terminal of diode D3 is connected to the common connection point between the excitation coil J1 of the relay and resistor R5. One end of the normally open switch K1 of the relay is connected to the same-name terminal of coupling coil L3. The other end of the normally open switch K1 of the relay is grounded.

[0043] The collector of transistor T3 is connected to the output terminal of the DC boost circuit through resistor R6. The emitter of transistor T3 is grounded, the base of transistor T3 is connected to the negative terminal of diode D2, and the positive terminal of diode D2 is connected to the control output terminal of the control transmission module. The above structure allows for the application of a test voltage to the overhead ground wire, resulting in high stability. More importantly, it provides excellent protection for the circuitry at the front end of the coupling circuit. The protection principle is as follows: When a lightning current passes through the overhead ground wire, coil L3 will induce a high voltage. After passing through a voltage divider detection circuit composed of resistors R9 and R10, the Zener diode ZD1 breaks down, outputting a high level to optocoupler G1 (when there is no lightning current, the Zener diode ZD1 is cut off, meaning its forward voltage is greater than the test voltage). Optocouplers G1 and G2 simultaneously conduct. At this time, the detection input terminal connected to the positive terminal of diode D4 changes from a high level to a low level. The controller then detects the presence of a lightning current and begins timing. Simultaneously, the conduction of optocoupler G1 triggers the conduction of thyristor Q2, causing the normally open switch of the relay to close, thus creating a short circuit across L3. L3 itself forms a loop to eliminate the induced voltage and current. When the controller reaches the set time (obtained through testing), the control transistor Q3 briefly conducts, turning off the thyristor. L3 can then couple to L4 for output. In existing technology, this type of protection is generally achieved by connecting a TVS (transient current suppression) diode across L3. In reality, protection can be achieved momentarily when lightning current is generated, but the inductive effect and self-induced electromotive force of L3 are ignored. When lightning current is generated, coil L3 will induce a high voltage. Although the TVS diode conducts momentarily, allowing L3 to absorb the induced voltage surge, its terminal voltage gradually decreases due to the self-inductance of L3. When it decreases to the cutoff voltage of the TVS diode, it is equivalent to reopening the short circuit between L3 and TVS. The induced electromotive force of L3 will then be applied to the front-end circuit, thus impacting the front-end circuit. Therefore, existing technology cannot provide effective protection.

[0044] The turns ratio of L3 to L4 is 1:1.

[0045] In this embodiment, the control transmission module includes a controller, a wireless communication module, and a positioning circuit;

[0046] The controller communicates with the remote monitoring host via a wireless communication module and with the positioning circuit. The controller's detection input is connected to the positive terminal of diode D4, and its control output is connected to the positive terminal of diode D2. The controller's sampling input is connected to the output of the acquisition unit. The positioning circuit uses an existing GPS or BeiDou positioning circuit, the wireless communication module uses an existing 4G or 5G module, or an existing 2.4G power wireless private network module, and the controller uses an existing microcontroller. The controller uploads the real-time collected grounding resistance information to the monitoring host, including the current location information in the uploaded information. The remote monitoring host is used for monitoring and early warning.

[0047] In this embodiment, the acquisition unit includes a voltage transformer, a current transformer, a first bandpass filter, a second bandpass filter, a voltage rectifier circuit, a current rectifier circuit, a voltage sampling circuit (which is an existing voltage divider sampling circuit), a current sampling circuit (which is an existing voltage divider sampling circuit), and a dual-channel analog-to-digital converter. Each circuit in the acquisition unit uses existing circuits, and the two bandpass filters only allow the frequency of the test voltage to pass through, thereby preventing external interference.

[0048] The output terminal of the voltage transformer is connected to the input terminal of the first bandpass filter, the output terminal of the first bandpass filter is connected to the input terminal of the voltage rectifier circuit, the output terminal of the voltage rectifier circuit is connected to the input terminal of the voltage sampling circuit, and the output terminal of the voltage sampling circuit is connected to the input terminal of the voltage sampling channel of the dual-channel analog-to-digital converter.

[0049] The output of the current transformer is connected to the input of the second bandpass filter, the output of the second bandpass filter is connected to the input of the current rectifier circuit, the output of the current rectifier circuit is connected to the input of the current sampling circuit, and the output of the current sampling circuit is connected to the input of the current sampling channel of the dual-channel analog-to-digital converter. The output of the voltage sampling channel and the output of the current sampling channel of the dual-channel analog-to-digital converter are connected to the sampling input of the controller. The current transformer and the voltage transformer are located between the test voltage loading point of the overhead ground wire and the ground.

[0050] In this embodiment, the power module includes a power voltage transformer, a rectifier circuit, a lithium battery, a battery management circuit, and a voltage regulator circuit.

[0051] The power supply voltage transformer is installed on the transmission line. Its output is connected to the input of a rectifier circuit, which in turn connects to the input of an RC filter circuit. The output of the RC filter circuit is then connected to the output of a voltage regulator circuit, which outputs 5V DC. The battery management circuit's input is connected to the output of the RC filter circuit, and its output is connected to a lithium battery. The lithium battery's output supplies power to the control transmission module and the DC boost circuit. The power supply voltage transformer is simply an existing voltage transformer, named as such to distinguish it from the aforementioned voltage transformers. The rectifier circuit's output can be configured with an RC filter for current and voltage limiting and filtering. The battery management circuit includes a voltage divider circuit composed of resistors and a battery management chip. The voltage divider circuit steps down the voltage before inputting it to the battery management chip, which uses the existing CN3765 lithium battery management chip. The voltage regulator circuit uses the existing LM7805 voltage regulator chip, which can directly supply power to the control transmission module without requiring multiple voltage regulator circuits.

[0052] All the rectifier circuits mentioned above are existing bridge rectifier circuits composed of diodes. In the above, except when the overhead ground wire is grounded, the overhead ground wire is directly connected to the earth, and all other groundings are at the 0 potential point in the circuit.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An overhead ground wire grounding detection system, characterized in that: It includes a power supply module, a DC boost module, an inverter module, a first filter module, a second filter module, a coupling loading unit, a control transmission module, and a data acquisition unit; The power supply module has its output terminal connected to the input terminal of the DC boost module. The output terminal of the DC boost module is connected to the input terminal of the inverter module through the first filter module. The output terminal of the inverter module is connected to the input terminal of the second filter module. The output terminal of the second filter module is connected to the input terminal of the coupling loading unit. The coupling loading unit applies a test voltage to the overhead ground wire through electromagnetic induction. The acquisition unit is used to acquire the voltage and current of the overhead ground wire and output them to the control transmission module. The control transmission module determines the grounding resistance value of the overhead ground wire based on the voltage and current output by the acquisition unit. The DC boost module includes resistors R1, R2, R3, and R4, inductor L1, capacitors C1, C2, and C3, transistors T1 and T2, NMOS transistor Q1, diode D1, operational amplifier U1, and control chip U1. One end of resistor R1 is connected to one end of inductor L1. The common connection point between resistor R1 and inductor L1 serves as the input terminal of the DC-DC boost module. The anode of diode D1 is connected to the other end of inductor L1, and the cathode of diode D1 is grounded through capacitor C2. The cathode of diode D2 serves as the output terminal of the DC-DC boost module. The other end of resistor R1 is connected to the collector of transistor T1. The emitter of transistor T1 is connected to the emitter of transistor T2. The collector of transistor T2 is grounded. The emitter of transistor T1 is connected to the gate of NMOS transistor Q1 through resistor R2. Transistors T1 and T2... The base of the transistor is connected to the control output terminal of the control chip U2 via capacitor C3. The drain of the NMOS transistor Q1 is connected to the positive terminal of the diode D1, and the source of the NMOS transistor Q1 is grounded. The other end of the resistor R3 is connected to the negative terminal of the diode D1, and the other end of the resistor R3 is grounded via resistor R4. The common connection point of resistors R4 and R3 is connected to the non-inverting input of the operational amplifier U1. The inverting input of the operational amplifier U1 is directly connected to the output terminal of the operational amplifier U1. The output terminal of the operational amplifier U1 is connected to the detection input terminal of the control chip U2. Among them, transistor T2 is a P-type transistor, and the control chip U2 is an L6562 chip.

2. The overhead ground wire grounding detection system according to claim 1, characterized in that: The inverter module includes an inverter, an inverter drive circuit, and a transformer; The inverter's power input terminal is connected to the output terminal of the DC boost module, the inverter's power output terminal is connected to the primary winding of the transformer, the transformer's secondary winding is connected to the input terminal of the coupling loading module, the coupling loading module, and the control output terminal of the inverter drive circuit are connected to the control input terminal of the inverter, which in turn is connected to the control transmission module.

3. The overhead ground wire grounding detection system according to claim 1, characterized in that: The coupling loading unit includes a coupling circuit and a lightning protection circuit; The coupling circuit includes coupling coil L3, coupling coil L4, resistor R11 and capacitor C5; The same-name terminal of coupling coil L3 is connected to the output terminal of the second filter module as the input terminal of the coupling loading unit. The opposite-name terminal of coupling coil L3 is grounded. The same-name terminal of coupling coil L4 is connected to the opposite-name terminal of coupling coil L4 through resistor R11 and capacitor C5 in parallel. Coupling coil L3 and coupling coil L4 form a transformer structure and coupling coil L4 is wrapped with an overhead ground wire. The lightning protection circuit includes a relay, resistors R5, R6, R7, R8, R9, R10, R12, R13, diodes D2, D3, and D4, a silicon controlled rectifier Q2, a transistor T3, optocouplers G1 and G2, a Zener diode ZD1, and a capacitor C4. One end of resistor R9 is connected to the same-name terminal of coupling coil L3. The other end of resistor R9 is grounded after being connected in parallel with resistor R10 and capacitor C4. The common connection point of resistors R9 and R10 is connected to the negative terminal of Zener diode ZD1. The positive terminal of Zener diode ZD1 is connected to the positive terminal of LED of optocoupler G1 through resistor R8. The negative terminal of LED of optocoupler G1 is connected to the positive terminal of LED of optocoupler G2. The negative terminal of LED of optocoupler G2 is grounded. The collector of phototransistor of optocoupler G2 is connected to the negative terminal of diode D4. The positive terminal of diode D4 is connected to the detection input terminal of control transmission module. The emitter of phototransistor of optocoupler G2 is grounded. The emitter of phototransistor of optocoupler G1 is connected to... Resistor R12 is grounded. The collector of the phototransistor in optocoupler G1 is connected to the output of the DC-DC boost module through resistor R7. The emitter of optocoupler G1 is connected to the control electrode of thyristor Q2 through resistor R13. The negative terminal of thyristor Q2 is grounded. The positive terminal of thyristor Q2 is connected to one end of the excitation coil J1 of the relay. The other end of the excitation coil J2 of relay J1 is connected to the output of the DC-DC boost module through resistor R5. The positive terminal of diode D3 is connected to the positive terminal of thyristor Q2. The negative terminal of diode D3 is connected to the common connection point between the excitation coil J1 of the relay and resistor R5. One end of the normally open switch K1 of the relay is connected to the same-name terminal of coupling coil L3. The other end of the normally open switch K1 of the relay is grounded. The collector of transistor T3 is connected to the output terminal of the DC boost circuit through resistor R6. The emitter of transistor T3 is grounded, the base of transistor T3 is connected to the negative terminal of diode D2, and the positive terminal of diode D2 is connected to the control output terminal of the control transmission module.

4. The overhead ground wire grounding detection system according to claim 3, characterized in that: The control transmission module includes a controller, a wireless communication module, and a positioning circuit; The controller is connected to the remote monitoring host via a wireless communication module and to the positioning circuit. The detection input terminal of the controller is connected to the positive terminal of diode D4, the control output terminal of the controller is connected to the positive terminal of diode D2, and the sampling input terminal of the controller is connected to the output terminal of the acquisition unit.

5. The overhead ground wire grounding detection system according to claim 4, characterized in that: The acquisition unit includes a voltage transformer, a current transformer, a first bandpass filter, a second bandpass filter, a voltage rectifier circuit, a current rectifier circuit, a voltage sampling circuit, a current sampling circuit, and a dual-channel analog-to-digital converter. The output terminal of the voltage transformer is connected to the input terminal of the first bandpass filter, the output terminal of the first bandpass filter is connected to the input terminal of the voltage rectifier circuit, the output terminal of the voltage rectifier circuit is connected to the input terminal of the voltage sampling circuit, and the output terminal of the voltage sampling circuit is connected to the input terminal of the voltage sampling channel of the dual-channel analog-to-digital converter. The output of the current transformer is connected to the input of the second bandpass filter. The output of the second bandpass filter is connected to the input of the current rectifier circuit. The output of the current rectifier circuit is connected to the input of the current sampling circuit. The output of the current sampling circuit is connected to the input of the current sampling channel of the dual-channel analog-to-digital converter. The output of the voltage sampling channel and the output of the current sampling channel of the dual-channel analog-to-digital converter are connected to the sampling input of the controller.

6. The overhead ground wire grounding detection system according to claim 1, characterized in that: The power module includes a power voltage transformer, a rectifier circuit, a lithium battery, a battery management circuit, and a voltage regulator circuit. The power supply voltage transformer is installed on the transmission line. The output terminal of the power supply voltage transformer is connected to the input terminal of the rectifier circuit. The output terminal of the rectifier circuit is connected to the input terminal of the RC filter circuit. The output terminal of the RC filter circuit is connected to the output terminal of the voltage regulator circuit, which outputs 5V DC power. The power input terminal of the battery management circuit is connected to the output terminal of the RC filter circuit. The output terminal of the battery management circuit is connected to the lithium battery. The output terminal of the lithium battery supplies power to the control transmission module and the DC boost circuit.

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