Three-phase five-column voltage transformer auxiliary device and method convenient for direct current test transmission

Abstract

The invention relates to the technical field of ground fault searching, and provides a three-phase five-column voltage transformer auxiliary device convenient for direct current test transmission, which effectively analyzes current characteristics through a control unit and can quickly identify direct current, thereby controlling an execution module to disconnect ground connection of a three-phase five-column voltage transformer, and improving the reliability of the three-phase five-column voltage transformer. Isolating a three-phase five-column voltage transformer in the test transmission section; through the wireless transmission module, an operator can remotely monitor a current signal judgment result in real time and remotely control the execution module, so that the dependence on field manpower is reduced; after the direct current test transmission is finished, a command for recovering the grounding of the three-phase five-column type voltage transformer is sent to the control unit through the remote control module, the control unit controls the opening and closing control circuit to work and the normally closed contact of the high-voltage vacuum relay to recover the normally closed state, so that the grounding connection of the three-phase five-column type voltage transformer is recovered, and the working efficiency is improved; the fault searching efficiency is improved, the operation risk is reduced, and the driving safety risk is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ground fault detection, in particular to a three-phase five-column voltage transformer auxiliary device and method for facilitating direct current test transmission. Background Art

[0002] 10kV distribution lines are characterized by long lines, many branches, many equipments, and many underground cables. The lines are located in complex terrain, across plateau mountains and canyons, with large altitude differences. Disasters are frequent in the area where the lines are located, with frequent lightning, strong winds and many tree obstacles in some areas, resulting in frequent grounding faults in overhead and underground lines. Grounding faults account for about 70% of the total faults in distribution lines.

[0003] When searching for ground faults, the general principle is to conduct a preliminary analysis first, then conduct a forced power supply test, use the "binary method" to determine the fault section, and first isolate and transfer power before emergency repair. Since the current distribution automation construction mode adopts the main line time voltage type and branch current extreme difference type, a large number of three-phase five-column voltage transformers are installed on the line, and the primary side neutral point is directly grounded.

[0004] If there is a three-phase five-column voltage transformer on the line, the insulation resistance meter, DC test transmitter and other instruments will perform ground fault tests. If there is no fault in the line, the insulation cannot be shaken and the DC test will not be successful. The three-phase five-column voltage transformer in the test section needs to be isolated.

[0005] Before using an insulation resistance meter, DC test transmitter, etc. to perform fault testing, it is necessary to first isolate the voltage transformer on the line that uses direct neutral point grounding, and only after confirming that the substation has been switched to cold standby can the test be performed.

[0006] Therefore, there is an urgent need for a three-phase five-column voltage transformer auxiliary device and method that is convenient for DC trial transmission, which can automatically disconnect the primary side neutral point of the three-phase five-column voltage transformer from the ground during DC trial transmission, isolate the three-phase five-column voltage transformer in the trial transmission section, improve fault finding efficiency, reduce operational risks, and reduce driving safety risks. Summary of the invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to provide a three-phase five-column voltage transformer auxiliary device which is convenient for DC test transmission. The device can automatically disconnect the three-phase five-column voltage transformer from the ground during DC test transmission, isolate the three-phase five-column voltage transformer in the test transmission section, improve fault finding efficiency, reduce operational risks, and reduce driving safety risks.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission, comprising: a remote control module, a current signal acquisition module, a control unit, a wireless transmission module, a power supply module and an execution module; the control unit is electrically connected to the current signal acquisition module, the wireless transmission module, the power supply module and the execution module respectively;

[0010] The current signal acquisition module is used to collect the current signal of the grounding wire of the three-phase five-column voltage transformer and output the detected current signal to the control unit;

[0011] The wireless transmission module is used for communication between the remote control module and the control unit;

[0012] The control unit is used to receive the current signal output by the current signal acquisition module, analyze and judge the current signal, and control the execution module to connect or disconnect the three-phase five-column voltage transformer to the ground according to the judgment result;

[0013] The remote control module is used to display the current signal judgment result and remotely control the execution module to connect or disconnect the three-phase five-column voltage transformer to the ground;

[0014] The power supply module is used to provide the required voltage to the current signal acquisition module, the control unit and the execution module.

[0015] Preferably, the analysis and judgment of the current signal is performed based on the following method:

[0016] Step 1: Collect current signals through the current signal acquisition module and transmit them to the control unit;

[0017] Step 2, the control unit filters the current signal collected by the current signal collection module and extracts the current signal characteristics;

[0018] Step 3: If there is a DC signal in the current signal, the control unit controls the execution module to disconnect the normally closed contact of the high-voltage vacuum relay to disconnect the ground wire of the three-phase five-column voltage transformer from the ground.

[0019] Preferably, the current signal acquisition module comprises: a current sensor and a current detection circuit; the current sensor is a Hall effect current sensor.

[0020] Preferably, the current detection circuit includes: a current sensor interface U13, resistors R12-R15, R24, R25, and an operational amplifier U14; the current sensor interface U13 is connected to the output interface of the Hall effect current sensor, and the output signal of the Hall effect current sensor is connected to pin 2 of the operational amplifier U14 through pin 3 of the current sensor interface U13; resistors R12 and R13 are connected in series between pin 3 of the current sensor interface U13 and pin 2 of the operational amplifier U14, and resistor R14 is connected to ground between resistor R12 and resistor R13; pin 3 and pin 8 of the operational amplifier U14 are connected to a 3.3V power supply, R15 and resistor R24 ​​are connected in series between pin 3 and the 3.3V power supply, and resistor R24 ​​is connected to ground between the resistor R24 ​​and the 3.3V power supply through resistor R25; pin 1, pin 2, and pin 4 of the current sensor interface U13 are connected to -12V, ground, and +12V, respectively; pin 1 of the operational amplifier U14 is connected to the control unit.

[0021] Preferably, the execution module comprises: a high-voltage vacuum relay and an opening and closing control circuit; the high-voltage vacuum relay has normally open and normally closed contacts.

[0022] Preferably, the opening and closing control circuit includes: an optocoupler isolation U15, a transistor Q1, a high-voltage vacuum relay control coil interface CN3 and a diode D2; pin 1 of the optocoupler isolation U15 is connected to the control unit, pin 2 is grounded, pin 4 is connected to the 24V power supply, and pin 3 is connected to the base of the transistor Q1; the two wiring terminals of the high-voltage vacuum relay control coil interface CN3 are respectively connected to the high-voltage vacuum relay control coil, pin 1 of the high-voltage vacuum relay control coil interface CN3 is connected to the collector of the transistor Q1 and the positive electrode of the diode D2, and pin 2 is connected to the 24V power supply and the negative electrode of the diode D2; the emitter of the transistor Q1 is grounded.

[0023] Preferably, the power supply module includes: a 24V to 5V step-down circuit, a 5V to 3.3V step-down circuit, a 24V to positive and negative 12V circuit, and a 24V isolated power supply circuit.

[0024] Preferably, the control unit adopts an STM32F103C8T6 single-chip microcomputer, and the STM32F103C8T6 single-chip microcomputer is externally connected with a high-speed crystal oscillator circuit, a power-on reset circuit, a startup mode selection circuit, a power decoupling circuit and a program download circuit.

[0025] Another object of the present invention is to provide a three-phase five-column voltage transformer auxiliary method that is convenient for DC test transmission, using the above three-phase five-column voltage transformer auxiliary device that is convenient for DC test transmission, comprising the following steps:

[0026] S1, connect the normally closed contact of the high-voltage vacuum relay in series with the grounding wire of the three-phase five-column voltage transformer;

[0027] S2, installing a current sensor on the grounding wire of a three-phase five-column voltage transformer to collect the current signal of the grounding wire of the three-phase five-column voltage transformer in real time;

[0028] S3, collecting current signals through the current signal collection module and transmitting them to the control unit;

[0029] S4, the control unit filters the current signal collected by the current signal collection module and extracts the current signal characteristics;

[0030] If there is a DC signal in the current signal, the control unit controls the opening and closing control circuit to work, and the normally closed contact of the high-voltage vacuum relay is disconnected, thereby disconnecting the three-phase five-column voltage transformer from the ground. At the same time, the control unit controls the wireless transmission module to send the current signal judgment result to the remote control module;

[0031] S6. After the DC trial transmission is completed, a command to restore the grounding of the three-phase five-column voltage transformer is sent to the control unit through the remote control module. The control unit controls the opening and closing control circuit to work, and the normally closed contacts of the high-voltage vacuum relay are restored to normally closed, thereby restoring the ground connection of the three-phase five-column voltage transformer.

[0032] The invention discloses a three-phase five-column voltage transformer auxiliary device which is convenient for direct current test transmission and has the following beneficial effects.

[0033] The present invention collects the current signal of the grounding wire of the three-phase five-column voltage transformer in real time through the current signal acquisition module, and can quickly identify the DC current by effectively analyzing the current characteristics through the control unit, so as to control the execution module to disconnect the ground connection of the three-phase five-column voltage transformer and isolate the three-phase five-column voltage transformer in the test transmission section; through the wireless transmission module, the operator can remotely monitor the current signal judgment result in real time and remotely control the execution module, thereby reducing the dependence on on-site manual work; after the DC test transmission is completed, the remote control module sends a command to restore the grounding of the three-phase five-column voltage transformer to the control unit, the control unit controls the opening and closing control circuit to work, and the normally closed contacts of the high-voltage vacuum relay are restored to normally closed, thereby restoring the ground connection of the three-phase five-column voltage transformer, simplifying the operation after the DC test transmission is completed, and the ground connection of the three-phase five-column voltage transformer can be quickly restored, thereby improving work efficiency, improving fault finding efficiency, reducing operation risks, and reducing driving safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The figure is a schematic block diagram of the system structure of the present invention.

[0035] Figure 2 This is a partial circuit schematic diagram of the power supply module of the present invention.

[0036] Figure 3 This is a partial circuit schematic diagram of the power supply module of the present invention.

[0037] Figure 4 This is a partial circuit schematic diagram of the power supply module of the present invention.

[0038] Figure 5 This is a partial circuit schematic diagram of the power supply module of the present invention.

[0039] Figure 6 This is a partial circuit schematic diagram of the power supply module of the present invention.

[0040] Figure 7 It is the principle diagram of the current detection circuit of the present invention.

[0041] Figure 8 It is a circuit schematic diagram of the control unit of the present invention.

[0042] Fig. 9 This is a partial circuit schematic diagram of the power supply module of the present invention.

[0043] In the attached figure: 1. remote control module; 2. current signal acquisition module; 21. current sensor; 22. current detection circuit; 3. control unit; 4. wireless transmission module; 5. power supply module; 6. execution module; 61. high-voltage vacuum relay; 62. opening and closing control circuit; 7. three-phase five-column voltage transformer; 8. grounding wire. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0045] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0046] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0047] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0048] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0049] Example 1

[0050] Reference Figure 1 , a three-phase five-column voltage transformer 7 auxiliary device convenient for DC test transmission, comprising: a remote control module 1, a current signal acquisition module 2, a control unit 3, a wireless transmission module 4, a power supply module 5 and an execution module 6; the control unit 3 is electrically connected to the current signal acquisition module 2, the wireless transmission module 4, the power supply module 5 and the execution module 6 respectively;

[0051] The current signal acquisition module 2 is used to acquire the current signal of the grounding wire 8 of the three-phase five-column voltage transformer 7, and output the detected current signal to the control unit 3;

[0052] A wireless transmission module 4, used for communication between the remote control module 1 and the control unit 3;

[0053] The control unit 3 is used to receive the current signal output by the current signal acquisition module 2, analyze and judge the current signal, and control the execution module 6 to connect or disconnect the three-phase five-column voltage transformer 7 to the ground according to the judgment result;

[0054] As a preferred embodiment, in this embodiment Fig. 9As shown, the control unit 3 uses the STM32F103C8T6 single-chip microcomputer, and the STM32F103C8T6 single-chip microcomputer is externally connected with a high-speed crystal oscillator circuit, a power-on reset circuit, a startup mode selection circuit, a power decoupling circuit, and a program download circuit. The STM32F103C8T6 not only has a large storage space, but also has powerful computing power. In terms of power supply, the STM32F103C8T6 uses a stable 3.3V power supply to ensure the stable operation of the MCU and the accuracy of data processing.

[0055] As the core of the whole device, STM32F103C8T6 successfully realizes real-time monitoring and data analysis of the device status with its excellent performance, rich functions and flexible connection methods. The basic circuit of MCU operation requires an external high-speed crystal oscillator circuit, a power-on reset circuit, a startup mode selection circuit, a power decoupling circuit and a program download circuit. In some circuits, H1 is the program download circuit. C15, C16 and X1 form an external high-speed crystal oscillator circuit, C27, C28, C29 form a power filter circuit, and R20, SW1, and C30 form a reset circuit.

[0056] Remote control module 1, used to display the current signal judgment result and remotely control execution module 6 to connect or disconnect the three-phase five-column voltage transformer 7 to the ground;

[0057] The power supply module 5 is used to provide the required voltage to the current signal acquisition module 2, the control unit 3 and the execution module 6; the current signal of the grounding wire 8 of the three-phase five-column voltage transformer 7 is collected in real time through the current signal acquisition module 2, and the current characteristics are effectively analyzed by the control unit 3, so that the DC current can be quickly identified, thereby controlling the execution module 6 to disconnect the three-phase five-column voltage transformer 7 from the ground and isolate the three-phase five-column voltage transformer 7 in the test section; through the wireless transmission module 4, the operator can remotely monitor the current signal judgment result in real time and remotely control the execution module 6 to reduce the dependence on on-site manual labor.

[0058] In this embodiment, the current signal is analyzed and judged based on the following method:

[0059] Step 1: Collect current signals through the current signal acquisition module 2 and transmit them to the control unit 3;

[0060] Step 2, the control unit 3 filters the current signal collected by the current signal collection module 2 and extracts the current signal characteristics;

[0061] Step 3: If there is a DC signal in the current signal, the control unit 3 controls the execution module 6 to disconnect the ground connection of the three-phase five-column voltage transformer 7. The control unit 3 controls the execution module 6 to disconnect the normally closed contact of the high-voltage vacuum relay 61 to disconnect the ground wire 8 of the three-phase five-column voltage transformer 7 from the ground.

[0062] As a preference, the power supply module 5 in this embodiment includes: a 24V to 5V step-down circuit, a 5V to 3.3V step-down circuit, a 24V to positive and negative 12V circuit, and a 24V isolated power supply circuit. Please refer to Figure 2 CN1 is the main interface for connecting the battery, which is responsible for introducing the DC power provided by the battery into the auxiliary device. CN2 is specifically used to connect the battery charging port, allowing external charging devices to charge the battery through this interface to maintain sufficient power. U7 is a switch interface that can control the on and off of the power supply. The battery voltage processed by the switch interface U7 is output through its second pin;

[0063] Please refer to Figure 3 , 24V to 5V step-down circuit, using step-down chip U8, step-down chip U8 adopts LMR14050SDDAR, the input of step-down chip U8 comes from the second foot of switch interface U7, the 24V voltage of the second foot of switch interface U7 is passed Figure 3 The capacitors C11 and C12 in the filter filter the 24V power supply before it enters the second pin of the buck chip U8. Figure 3 After the resistor R5 in the circuit, it enters the pin 3 of U8 to control the output of 5V voltage; Figure 3 The resistors R3 and R7 divide the output voltage and output it to the FB pin of the buck chip U8 to achieve the function of controlling the output voltage. The 5V voltage is filtered by capacitors C8 and C9 and then output to provide power for subsequent circuits;

[0064] Please refer to Figure 4 The 5V to 3.3V step-down circuit uses the step-down chip U9. The step-down chip U9 adopts TPRT9013-33GB. The input of the step-down chip U9 comes from the 24V to 5V step-down circuit. The 5V voltage output by the 24V to 5V step-down circuit filters the 5V power supply through capacitor C14, and then enters pin 1 of the step-down chip U9. After filtering through capacitor C10, it outputs 3.3V. The subsequent circuit 3.3V is output from here.

[0065] Please refer to Figure 5, 24V to positive and negative 12V circuit, using isolated power supply module M1, isolated power supply module M1 adopts URA2412S-6WVR3, its power supply part comes from the second foot of switch interface U7, through the circuit composed of inductor L2 and capacitors C18 and C17, it is input to the No. 2 pin of isolated power supply module M1 after filtering, after being processed by isolated power supply module M1, the voltage is output from No. 6 and No. 7 pins of M1, and then filtered through inductors L3 and L6, capacitors C24 and C19 to obtain +12V and -12V voltages;

[0066] Please refer to Figure 6 , 24V isolated power supply circuit, this part of the circuit generates another 24V power supply from the 24V voltage, which plays an isolation role on the circuit to prevent the circuit from being damaged by high voltage. The power supply of this part comes from the second pin of the switch interface U7. The power supply of this part is filtered by the circuit composed of inductor L4 and capacitors C20 and C21 and input to pin 2 of the isolated power supply module U11. After being processed by the isolated power supply module U11, the voltage is output from pins 6 and 7 of the isolated power supply module U11 and filtered by inductor L5, capacitors C22 and C23 to obtain another 24V voltage. The isolated power supply module U11 adopts URB2424S-6WR3.

[0067] Preferably, the current signal acquisition module 2 in this embodiment includes: a current sensor 21 and a current detection circuit 22; the current sensor 21 is a Hall effect current sensor 21, and the Hall effect current sensor 21 is ACS712.

[0068] As a preference, please refer to Figure 7In this embodiment, the current detection circuit 22 includes: a current sensor 21 interface U13, resistors R12-R15, R24, R25, and an operational amplifier U14; the current sensor 21 interface U13 is connected to the output interface of the Hall effect current sensor 21, and the output signal of the Hall effect current sensor 21 is connected to the pin 2 of the operational amplifier U14 through the pin 3 of the current sensor 21 interface U13; resistors R12 and R13 are connected in series between the pin 3 of the current sensor 21 interface U13 and the pin 2 of the operational amplifier U14, and the resistor R12 and the resistor R13 are grounded through the resistor R14; the operational amplifier U14 pin 3 and pin 8 are connected to the 3.3V power supply, and R15 and resistor R24 ​​are connected in series between the pin 3 and the 3.3V power supply, and the resistor R24 ​​and the 3.3V power supply are grounded through the resistor R25; the current sensor 21 interface U13 pin 1, pin 2, and pin 4 are connected to -12V, ground, and +12V respectively; the operational amplifier U14 pin 1 is connected to the control unit 3. The signal of the current sensor 21 enters the operational amplifier U14 through pin 3 of the current sensor 21 interface U13, and is output from pin 1 after zero point detection composed of resistors R13, R15 and the operational amplifier U14. Such a circuit can detect DC signals in AC current.

[0069] Preferably, the execution module 6 in this embodiment includes: a high-voltage vacuum relay 61 and an opening and closing control circuit 62; the high-voltage vacuum relay 61 has normally open and normally closed contacts, and the high-voltage vacuum relay 61 adopts JPK-8-WP.

[0070] As a preferred embodiment, the opening and closing control circuit 62 in this embodiment includes: optocoupler isolation U15, transistor Q1, high-voltage vacuum relay 61 control coil interface CN3 and diode D2; pin 1 of optocoupler isolation U15 is connected to the control unit 3, pin 2 is grounded, pin 4 is connected to the 24V power supply, and pin 3 is connected to the base of transistor Q1; the two terminals of the high-voltage vacuum relay 61 control coil interface CN3 are respectively connected to the high-voltage vacuum relay 61 control coil, pin 1 of the high-voltage vacuum relay 61 control coil interface CN3 is connected to the collector of transistor Q1 and the positive electrode of diode D2, pin 2 is connected to the 24V power supply and the negative electrode of diode D2; the emitter of transistor Q1 is grounded. This part of the circuit is used to control the opening and closing of the high-voltage vacuum relay 61. The high-voltage vacuum relay 61 used has normally open and normally closed contacts. In this embodiment, normally closed contacts are used. The control unit 3 controls whether pin 1 of CN3 is grounded by controlling the voltage value at the EN network label, thereby controlling the on and off of the normally closed contact of the high-voltage vacuum relay 61. This part of the circuit also uses the U15 optocoupler isolation circuit to prevent damage to the control unit 3.

[0071] Example 2

[0072] Based on Example 1, in this embodiment, a three-phase five-column voltage transformer 7 auxiliary method for facilitating DC test transmission is provided, and the three-phase five-column voltage transformer 7 auxiliary device for facilitating DC test transmission in Example 1 is used, including the following steps:

[0073] S1, connect the normally closed contact of the high-voltage vacuum relay 61 in series with the grounding wire 8 of the three-phase five-column voltage transformer 7;

[0074] S2, installing the current sensor 21 on the ground wire 8 of the three-phase five-column voltage transformer 7, and collecting the current signal of the ground wire 8 of the three-phase five-column voltage transformer 7 in real time;

[0075] S3, collecting current signals through the current signal collection module 2, and transmitting them to the control unit 3;

[0076] S4, the control unit 3 filters the current signal collected by the current signal collection module 2, and extracts the current signal characteristics;

[0077] If there is a DC signal in the current signal, the control unit 3 controls the opening and closing control circuit 62 to work, and the normally closed contact of the high-voltage vacuum relay 61 is disconnected, thereby disconnecting the three-phase five-column voltage transformer 7 from the ground. At the same time, the control unit 3 controls the wireless transmission module 4 to send the current signal judgment result to the remote control module 1;

[0078] S6. After the DC test transmission is completed, the remote control module 1 sends a command to restore the grounding of the three-phase five-column voltage transformer 7 to the control unit 3, and the control unit 3 controls the opening and closing control circuit 62 to work, and the normally closed contacts of the high-voltage vacuum relay 61 are restored to normally closed, thereby restoring the ground connection of the three-phase five-column voltage transformer 7. After the DC test transmission is completed, the remote control module 1 sends a command to restore the grounding of the three-phase five-column voltage transformer 7 to the control unit 3, and the control unit 3 controls the opening and closing control circuit 62 to work, and the normally closed contacts of the high-voltage vacuum relay 61 are restored to normally closed, thereby restoring the ground connection of the three-phase five-column voltage transformer 7, simplifying the operation after the DC test transmission is completed, and the ground connection of the three-phase five-column voltage transformer 7 can be quickly restored, which improves work efficiency, improves fault finding efficiency, reduces operational risks, and reduces driving safety risks.

[0079] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The substitution may be a substitution of a part of the structure, device, method step, or a complete technical solution. Any equivalent replacement or change according to the technical solution and the inventive concept of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission, characterized in that: include: A remote control module, a current signal acquisition module, a control unit, a wireless transmission module, a power supply module and an execution module; the control unit is electrically connected to the current signal acquisition module, the wireless transmission module, the power supply module and the execution module respectively; The current signal acquisition module is used to collect the current signal of the grounding wire of the three-phase five-column voltage transformer and output the detected current signal to the control unit; The wireless transmission module is used for communication between the remote control module and the control unit; The control unit is used to receive the current signal output by the current signal acquisition module, analyze and judge the current signal, and control the execution module to connect or disconnect the three-phase five-column voltage transformer to the ground according to the judgment result; the remote control module is used to display the current signal judgment result and remotely control the execution module to connect or disconnect the three-phase five-column voltage transformer to the ground; The power supply module is used to provide the required voltage to the current signal acquisition module, the control unit and the execution module.

2. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission according to claim 1, characterized in that: The analysis and judgment of the current signal is performed based on the following method: Step 1: Collect current signals through the current signal acquisition module and transmit them to the control unit; Step 2, the control unit filters the current signal collected by the current signal collection module and extracts the current signal characteristics; Step 3: If there is a DC signal in the current signal, the control unit controls the execution module to disconnect the normally closed contact of the high-voltage vacuum relay to disconnect the ground wire of the three-phase five-column voltage transformer from the ground.

3. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission according to claim 1, characterized in that: The current signal acquisition module includes: a current sensor and a current detection circuit; the current sensor is a Hall effect current sensor.

4. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission according to claim 3, characterized in that: The current detection circuit includes: a current sensor interface U13, resistors R12-R15, R24, R25, and an operational amplifier U14; the current sensor interface U13 is connected to the output interface of the Hall effect current sensor, and the output signal of the Hall effect current sensor is connected to pin 2 of the operational amplifier U14 through pin 3 of the current sensor interface U13; resistors R12 and R13 are connected in series between pin 3 of the current sensor interface U13 and pin 2 of the operational amplifier U14, and resistor R14 is connected to ground between resistor R12 and resistor R13; pin 3 and pin 8 of the operational amplifier U14 are connected to a 3.3V power supply, R15 and resistor R24 ​​are connected in series between pin 3 and the 3.3V power supply, and resistor R24 ​​is connected to ground between the resistor R24 ​​and the 3.3V power supply through resistor R25; pin 1, pin 2, and pin 4 of the current sensor interface U13 are connected to -12V, ground, and +12V, respectively; pin 1 of the operational amplifier U14 is connected to a control unit.

5. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission according to claim 1, characterized in that: The execution module includes: a high-voltage vacuum relay and an opening and closing control circuit; the high-voltage vacuum relay has normally open and normally closed contacts.

6. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission according to claim 5, characterized in that: The opening and closing control circuit includes: an optocoupler isolation U15, a transistor Q1, a high-voltage vacuum relay control coil interface CN3 and a diode D2; the pin 1 of the optocoupler isolation U15 is connected to the control unit, the pin 2 is grounded, the pin 4 is connected to the 24V power supply, and the pin 3 is connected to the base of the transistor Q1; the two wiring terminals of the high-voltage vacuum relay control coil interface CN3 are respectively connected to the high-voltage vacuum relay control coil, the pin 1 of the high-voltage vacuum relay control coil interface CN3 is connected to the collector of the transistor Q1 and the positive electrode of the diode D2, and the pin 2 is connected to the 24V power supply and the negative electrode of the diode D2; the emitter of the transistor Q1 is grounded.

7. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission according to claim 2, characterized in that: The power supply module includes: a 24V to 5V step-down circuit, a 5V to 3.3V step-down circuit, a 24V to positive and negative 12V circuit and a 24V isolated power supply circuit.

8. A three-phase five-column voltage transformer auxiliary device convenient for DC test transmission according to claim 5, characterized in that: The control unit adopts an STM32F103C8T6 single-chip microcomputer, and the STM32F103C8T6 single-chip microcomputer is externally connected with a high-speed crystal oscillator circuit, a power-on reset circuit, a startup mode selection circuit, a power decoupling circuit and a program download circuit.

9. A three-phase five-column voltage transformer auxiliary method for facilitating DC test transmission, using the three-phase five-column voltage transformer auxiliary device for facilitating DC test transmission in claims 1-8, characterized in that: The following steps are involved: S1, connect the normally closed contact of the high-voltage vacuum relay in series with the grounding wire of the three-phase five-column voltage transformer; S2, installing a current sensor on the grounding wire of a three-phase five-column voltage transformer to collect the current signal of the grounding wire of the three-phase five-column voltage transformer in real time; S3, collecting current signals through the current signal collection module and transmitting them to the control unit; S4, the control unit filters the current signal collected by the current signal acquisition module and extracts the current signal characteristics; if there is a DC signal in the current signal, the control unit controls the opening and closing control circuit to work, and the normally closed contact of the high-voltage vacuum relay is disconnected, thereby disconnecting the three-phase five-column voltage transformer from the ground, and at the same time, the control unit controls the wireless transmission module to send the current signal judgment result to the remote control module; S6. After the DC trial transmission is completed, a command to restore the grounding of the three-phase five-column voltage transformer is sent to the control unit through the remote control module. The control unit controls the opening and closing control circuit to work, and the normally closed contacts of the high-voltage vacuum relay are restored to normally closed, thereby restoring the ground connection of the three-phase five-column voltage transformer.

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