Secondary circuit insulation detection device

Abstract

The invention discloses a secondary circuit insulation detection device, and relates to the technical field of insulation detection devices, the secondary circuit insulation detection device comprises an insulation detector, a signal injection unit, a current transformer, a voltage acquisition unit, a control processing unit and an alarm unit, the current transformer is connected with a detection line, one end of the detection line is connected with a mutual inductance coil, and the other end of the detection line is connected with a power supply. A handle is arranged outside the connection position of the detection line and the mutual inductance coil. Through the arrangement of the brake handle, the pressurizing tank, the air bag, the liquid spraying pipe, a nozzle, a one-way valve, a brake cable, a pressing handle and a tension spring, when the position of a line with the low insulation property is detected, the brake handle is held and pressed, the brake cable is pulled, then the brake cable pulls the pressing handle to open the nozzle, and labeling liquid on the inner side of the pressurizing tank is sprayed to the line under the pressure effect of the air bag; maintenance personnel can accurately find the position needing to be maintained, and the maintenance efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of insulation detection devices, in particular to a secondary circuit insulation detection device. Background Art

[0002] When circuit equipment is running, some important electrical equipment needs to use secondary equipment, which needs DC power supply, and at the same time, the insulation effect of the secondary equipment circuit must be guaranteed. Insulation testing equipment can perform insulation testing on the secondary circuit to ensure that the circuit of the secondary equipment can operate safely and stably.

[0003] When using the existing circuit insulation detection device, the line position where the insulation is detected to be low cannot be marked in time, so that maintenance personnel cannot accurately find the position that needs maintenance, which reduces maintenance efficiency. At the same time, the current transformer in the existing detection device is not convenient for handheld operation, which affects the smooth progress of the detection process. In addition, for some complex secondary circuit systems, manual detection is difficult to comprehensively and carefully check the insulation conditions of various parts, and potential insulation hazards are easy to be missed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide a secondary circuit insulation detection device. By arranging a gate handle, a pressurized tank, an air bag, a liquid spraying pipe, a nozzle, a one-way valve, a gate wire, a pressure handle and a tension spring, when the line position with the lowest insulation is detected, the gate handle is squeezed to pull the gate wire, and then the gate wire pulls the pressure handle to open the nozzle, so that the marked liquid inside the pressurized tank is sprayed onto the line under the action of the air bag pressure, so that maintenance personnel can accurately find the position that needs maintenance, improve maintenance efficiency, and effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: a secondary circuit insulation detection device, comprising an insulation detector, a signal injection unit, a current transformer, a voltage acquisition unit, a control processing unit and an alarm unit, the current transformer is connected with a detection line, one end of the detection line is connected with a mutual inductance coil, a handle is arranged outside the connection position between the detection line and the mutual inductance coil, a gate handle is installed on the handle, a gate wire is connected to the gate handle, a pressure handle is arranged at one end of the gate wire away from the gate handle, a tension spring is installed on the lower side of the pressure handle, a nozzle is installed at one end of the tension spring, and a liquid spraying pipe is connected to the nozzle; The signal injection unit adopts a high-precision sine wave signal generator, which can generate a sine AC signal with stable frequency and precisely adjustable amplitude, with a frequency range of 1kHz-10kHz and an amplitude range of 1V-10V. The signal output by the signal generator is amplified by a power amplifier to meet the detection requirements of different secondary circuits. The output power of the power amplifier can reach 10W-50W, which can ensure that the injected signal has sufficient strength in the secondary circuit to accurately detect the insulation performance.

[0006] The signal injection unit is connected to the secondary circuit through an isolation transformer to achieve electrical isolation, prevent interference with the normal operation of the secondary circuit during the detection process, and also ensure the safety of the detection device. The ratio of the isolation transformer is reasonably selected according to the voltage level and detection requirements of the secondary circuit, generally 1:1 - 1:10, with good insulation performance and frequency response characteristics, can effectively transmit the injection signal, and isolate the DC component and power frequency interference signal in the secondary circuit.

[0007] Furthermore, the end of the liquid spray pipe away from the nozzle is connected to a pressurized tank, an air bag is arranged inside the pressurized tank, and a one-way valve is arranged on the outer side of the pressurized tank close to one end of the air bag.

[0008] Furthermore, a fastening ring is sleeved on one end of the mutual inductance coil, and a display screen is installed on the insulation tester.

[0009] Furthermore, a power connection is plugged into a side of the insulation tester, and a grounding wire is provided on one side of the power connection.

[0010] Furthermore, a signal line is provided between the current transformer and the insulation tester, and two ends of the signal line are respectively plugged into the insulation tester and the current transformer.

[0011] Furthermore, the pressurized tank is connected to the handle via threads, and the airbag is fixedly connected to the inner side of the pressurized tank.

[0012] Furthermore, one end of the liquid spraying pipe is connected to the pressurized tank, and the other end is connected to the nozzle.

[0013] Furthermore, the voltage sampling unit installs a high-resolution voltage sensor at the injection end and each detection point of the secondary circuit. The voltage sensor is designed based on the principle of capacitive voltage division, has high precision, high linearity and good stability, with a resolution of up to 0.1V and a measurable range of 0-1000V, and can accurately measure the voltage signal in the secondary circuit, including the injection signal and the induced voltage signal. The linearity error of the voltage sensor is less than ±0.5%, ensuring the accuracy and reliability of the voltage measurement.

[0014] Furthermore, the voltage acquisition unit is also equipped with a signal conditioning circuit to amplify, filter and perform analog-to-digital conversion on the signal output by the voltage sensor, convert it into a digital signal and transmit it to the subsequent signal processing unit. The amplifier in the signal conditioning circuit automatically adjusts the amplification factor according to the size of the voltage signal, ranging from 1 to 100 times. The filter can effectively remove power frequency interference and high-frequency noise. The sampling frequency and resolution of the ADC meet the requirements for high-precision acquisition of voltage signals, ensuring that the voltage information in the secondary circuit can be accurately obtained, providing accurate data basis for the calculation of insulation resistance and the diagnosis of insulation faults. Furthermore, the control processing unit is based on a high-performance microcontroller (MCU) or digital signal processor (DSP), which is responsible for the control and data processing of the entire detection device. MCU / DSP has powerful computing power and rich peripheral interfaces, and can quickly and accurately execute various algorithms and instructions, realize coordinated control of the signal injection unit, current acquisition unit and voltage acquisition unit, and perform real-time processing and analysis of the collected data.

[0015] Furthermore, the control processing unit has built-in advanced signal processing algorithms, such as fast Fourier transform (FFT), wavelet transform, etc., which are used to perform spectrum analysis and feature extraction on the collected current and voltage signals, accurately identify the useful components and interference components in the signal, and improve the accuracy and anti-interference ability of insulation resistance measurement. At the same time, it also has data storage function, which can store a large amount of test data and historical records for subsequent query, analysis and statistics. The storage capacity can reach more than 1GB, and the storage time interval can be set according to user needs, generally 1 hour to 24 hours.

[0016] The control processing unit is also equipped with communication interfaces, such as Ethernet interface, RS485 interface, USB interface, etc., to achieve communication connection with the host computer or other intelligent devices. Through the communication interface, the detection data can be uploaded to the monitoring center or the automatic management platform of the power system in real time, so that the operation and maintenance personnel can conduct remote monitoring and management; at the same time, it can also receive control instructions and parameter settings from the host computer to achieve remote operation and configuration of the detection device, which improves the intelligence and convenience of the detection device.

[0017] Furthermore, when it is detected that the insulation resistance of the secondary circuit is lower than the preset threshold or an insulation fault occurs, the alarm unit will immediately send out an audible and visual alarm signal to remind the operation and maintenance personnel to take timely measures to deal with it. The alarm threshold can be flexibly set according to the specific requirements and safety standards of the secondary circuit. The general insulation resistance threshold is 0.5MΩ - 10MΩ. When the insulation resistance is lower than the threshold, the device will send out an alarm signal and display detailed information such as the fault location and type on the display screen to help the operation and maintenance personnel quickly locate and solve the problem and ensure the safe operation of the power system.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The invention provides a gate handle, a pressurized tank, an air bag, a liquid spraying tube, a nozzle, a one-way valve, a gate wire, a pressure handle and a tension spring, so that when the position of the line with the bottom of the insulation is detected, the gate handle is held and pressed, so that the gate wire is pulled, and then the gate wire pulls the pressure handle to open the nozzle, so that the marked liquid inside the pressurized tank is sprayed onto the line under the pressure of the air bag, so that the maintenance personnel can accurately find the position that needs maintenance, thereby improving the maintenance efficiency; 2. The invention provides a handle, a fastening ring and a mutual inductance coil, so that the inspector can hold the handle and put the mutual inductance coil on the line to be inspected for mobile inspection, thereby improving the inspection efficiency.

[0019] 3. Based on the in-depth analysis of the collected current and voltage signals, the detection device of the present invention can quickly and accurately locate the location of the insulation fault and make a preliminary diagnosis of the fault type, such as insulation aging, moisture, damage, short circuit, etc. By judging the location and type of the fault, the operation and maintenance personnel can conduct targeted troubleshooting and repair, which greatly shortens the fault handling time, improves the operation and maintenance efficiency of the power system, and reduces power outage time and economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 For the present invention Figure 1 A schematic diagram of the enlarged structure at A in the middle; Figure 3 For the present invention Figure 1 Schematic diagram of the top cross-sectional structure of the medium pressure tank.

[0021] In the figure: 1. Insulation tester; 2. Display screen; 3. Power connection; 4. Ground wire; 5. Current transformer; 6. Signal wire; 7. Detection wire; 8. Mutual inductance coil; 9. Fastening ring; 10. Handle; 11. Nozzle; 12. Gate handle; 13. Spray pipe; 14. Pressurized tank; 15. Pressure handle; 16. Gate wire; 17. Airbag; 18. One-way valve; 19. Tension spring. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figure 1-3 , this embodiment provides a technical solution: a secondary circuit insulation detection device, including an insulation detector 1, a signal injection unit, a current transformer 5, a voltage acquisition unit, a control processing unit and an alarm unit, the current transformer 5 is connected with a detection line 7, one end of the detection line 7 is connected with a mutual inductance coil 8, a handle 10 is arranged outside the connection position between the detection line 7 and the mutual inductance coil 8, a gate handle 12 is installed on the handle 10, a gate wire 16 is connected to the gate handle 12, a pressure handle 15 is arranged at one end of the gate wire 16 away from the gate handle 12, a tension spring 19 is installed on the lower side of the pressure handle 15, a nozzle 11 is installed at one end of the tension spring 19, and a liquid spray pipe 13 is connected to the nozzle 11; The signal injection unit adopts a high-precision sine wave signal generator, which can generate a sine AC signal with stable frequency and precisely adjustable amplitude, with a frequency range of 1kHz-10kHz and an amplitude range of 1V-10V. The signal output by the signal generator is amplified by a power amplifier to meet the detection requirements of different secondary circuits. The output power of the power amplifier can reach 10W-50W, which can ensure that the injected signal has sufficient strength in the secondary circuit to accurately detect the insulation performance.

[0024] The signal injection unit is connected to the secondary circuit through an isolation transformer to achieve electrical isolation, prevent interference with the normal operation of the secondary circuit during the detection process, and also ensure the safety of the detection device. The ratio of the isolation transformer is reasonably selected according to the voltage level and detection requirements of the secondary circuit, generally 1:1 - 1:10, with good insulation performance and frequency response characteristics, can effectively transmit the injection signal, and isolate the DC component and power frequency interference signal in the secondary circuit.

[0025] like Figure 1-3As described above, when the insulation of the secondary circuit is tested, the positive and negative electrodes of the secondary circuit are connected through the power connection 3 respectively, the grounding wire 4 is grounded, and then the mutual inductance coil 8 is bypassed around the line to be tested, and the mutual inductance coil 8 is connected into a circular ring structure through the fastening ring 9. The tester holds the handle 10 and moves the mutual inductance coil 8 along the line. When the insulation on the line is low, the insulation tester 1 can detect the signal and issue an alarm reminder. The tester holds the gate handle 12 by hand to pull the gate wire 16, and then the gate wire 16 drives the pressure handle 15 to rotate, and the nozzle 11 is opened. The marked liquid in the pressurized tank 14 flows quickly along the spray pipe 13 to the nozzle 11 position under the action of the pressurized gas in the airbag 17, and is sprayed on the line through the nozzle 11, so that the poor insulation on the line is marked, which is convenient for maintenance personnel to find the location that needs maintenance in a timely and accurate manner. The one-way valve 18 on the pressurized tank 14 can facilitate the maintenance personnel to inflate the inside of the airbag 17 to ensure that the liquid inside the pressurized tank 14 has a certain spraying pressure.

[0026] The end of the liquid spraying pipe 13 away from the nozzle 11 is connected to a pressurized tank 14, an air bag 17 is arranged inside the pressurized tank 14, and a one-way valve 18 is arranged on the outer side of the pressurized tank 14 close to the end of the air bag 17. The one-way valve 18 allows pressurized gas to flow into the inside of the air bag 17 but not to flow out, thereby ensuring the gas pressure inside the air bag 17, so that the air bag 17 can squeeze and spray out the liquid in the pressurized tank 14 under the action of the high-pressure gas.

[0027] A fastening ring 9 is sleeved on one end of the mutual inductance coil 8. A display screen 2 is installed on the insulation tester 1. The display screen 2 can display the detection information and give an alarm in time when a line insulation problem is detected.

[0028] A power connection 3 is plugged into the side of the insulation tester 1, and a grounding wire 4 is provided on one side of the power connection 3. After the grounding wire 4 is grounded, a loop is ensured to be formed between the secondary circuit and the earth. When a place with poor insulation is detected, a complete loop can be formed with the earth, and then a signal change can be detected.

[0029] A signal line 6 is provided between the current transformer 5 and the insulation tester 1 , and two ends of the signal line 6 are plugged into the insulation tester 1 and the current transformer 5 respectively.

[0030] The pressurized tank 14 is connected to the handle 10 via threads, and the air bag 17 is fixedly connected to the inner side of the pressurized tank 14 .

[0031] One end of the liquid spraying pipe 13 is connected to the pressure tank 14 , and the other end is connected to the nozzle 11 .

[0032] The voltage sampling unit installs high-resolution voltage sensors at the injection end and each detection point of the secondary circuit. The voltage sensor is designed based on the principle of capacitive voltage division, has high precision, high linearity and good stability, with a resolution of up to 0.1V and a measurable range of 0-1000V. It can accurately measure the voltage signal in the secondary circuit, including the injection signal and the induced voltage signal. The linearity error of the voltage sensor is less than ±0.5%, ensuring the accuracy and reliability of voltage measurement.

[0033] In this embodiment, the voltage acquisition unit is also equipped with a signal conditioning circuit to amplify, filter and perform analog-to-digital conversion on the signal output by the voltage sensor, convert it into a digital signal and transmit it to the subsequent signal processing unit. The amplifier in the signal conditioning circuit automatically adjusts the amplification factor according to the size of the voltage signal, ranging from 1 to 100 times. The filter can effectively remove power frequency interference and high-frequency noise. The sampling frequency and resolution of the ADC meet the requirements for high-precision acquisition of voltage signals, ensuring that the voltage information in the secondary circuit can be accurately obtained, providing accurate data basis for the calculation of insulation resistance and the diagnosis of insulation faults. In this embodiment, the control processing unit is based on a high-performance microcontroller (MCU) or digital signal processor (DSP), which is responsible for the control and data processing of the entire detection device. MCU / DSP has powerful computing power and rich peripheral interfaces, and can quickly and accurately execute various algorithms and instructions, realize coordinated control of the signal injection unit, current acquisition unit and voltage acquisition unit, and perform real-time processing and analysis of the collected data.

[0034] In this embodiment, the control processing unit has built-in advanced signal processing algorithms, such as fast Fourier transform (FFT), wavelet transform, etc., which are used to perform spectrum analysis and feature extraction on the collected current and voltage signals, accurately identify the useful components and interference components in the signal, and improve the accuracy and anti-interference ability of insulation resistance measurement. At the same time, it also has a data storage function, which can store a large amount of detection data and historical records for subsequent query, analysis and statistics. The storage capacity can reach more than 1GB, and the storage time interval can be set according to user needs, generally 1 hour to 24 hours.

[0035] The control processing unit is also equipped with communication interfaces, such as Ethernet interface, RS485 interface, USB interface, etc., to achieve communication connection with the host computer or other intelligent devices. Through the communication interface, the detection data can be uploaded to the monitoring center or the automatic management platform of the power system in real time, so that the operation and maintenance personnel can conduct remote monitoring and management; at the same time, it can also receive control instructions and parameter settings from the host computer to achieve remote operation and configuration of the detection device, which improves the intelligence and convenience of the detection device.

[0036] In this embodiment, when it is detected that the insulation resistance of the secondary circuit is lower than a preset threshold or an insulation fault occurs, the alarm unit will immediately send out an audible and visual alarm signal to remind the operation and maintenance personnel to take timely measures to deal with it. The alarm threshold can be flexibly set according to the specific requirements and safety standards of the secondary circuit. The general insulation resistance threshold is 0.5MΩ - 10MΩ. When the insulation resistance is lower than the threshold, the device will send out an alarm signal and display detailed information such as the fault location and type on the display screen to help the operation and maintenance personnel quickly locate and solve the problem and ensure the safe operation of the power system.

[0037] Based on the in-depth analysis of the collected current and voltage signals, the detection device of the present invention can quickly and accurately locate the location of the insulation fault and make a preliminary diagnosis of the fault type, such as insulation aging, moisture, damage, short circuit, etc. By judging the location and type of the fault, the operation and maintenance personnel can conduct targeted fault troubleshooting and repair, which greatly shortens the fault handling time, improves the operation and maintenance efficiency of the power system, and reduces power outage time and economic losses.

[0038] The working principle of the secondary circuit insulation detection device provided by the present invention is as follows: Figure 1-Figure 3 As shown, when the insulation of the secondary circuit is tested, the positive and negative electrodes of the secondary circuit are connected through the power connection 3 respectively, and the grounding wire 4 is grounded. Then the mutual inductance coil 8 is bypassed around the line to be tested, and the mutual inductance coil 8 is connected into a circular ring structure through the fastening ring 9. The tester holds the handle 10 and moves the mutual inductance coil 8 along the line. When the insulation on the line is low, the insulation tester 1 can detect the signal and issue an alarm reminder. The tester holds the gate handle 12 by hand to pull the gate wire 16, and then the gate wire 16 drives the pressure handle 15 to rotate, and the nozzle 11 is opened. The marked liquid in the pressurized tank 14 flows quickly along the spray pipe 13 to the nozzle 11 under the action of the pressurized gas in the airbag 17, and is sprayed on the line through the nozzle 11, so that the poor insulation on the line is marked, which is convenient for maintenance personnel to find the location that needs maintenance in a timely and accurate manner. The one-way valve 18 on the pressurized tank 14 can facilitate the maintenance personnel to inflate the inside of the airbag 17 to ensure that the liquid inside the pressurized tank 14 has a certain spraying pressure.

[0039] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A secondary circuit insulation detection device, comprising an insulation detector (1), a signal injection unit, a current transformer (5), a voltage acquisition unit, a control processing unit and an alarm unit, characterized in that: The current transformer (5) is connected to a detection line (7), one end of the detection line (7) is connected to a mutual inductance coil (8), a handle (10) is provided outside the connection position between the detection line (7) and the mutual inductance coil (8), a gate handle (12) is installed on the handle (10), a gate wire (16) is connected to the gate handle (12), a pressure handle (15) is provided at one end of the gate wire (16) away from the gate handle (12), a tension spring (19) is installed on the lower side of the pressure handle (15), a nozzle (11) is installed at one end of the tension spring (19), and a liquid spraying pipe (13) is connected to the nozzle (11); The signal injection unit adopts a high-precision sine wave signal generator, which can generate a sine AC signal with stable frequency and precisely adjustable amplitude, with a frequency range of 1kHz - 10kHz and an amplitude range of 1V - 10V. The signal output by the signal generator is amplified by a power amplifier to meet the detection requirements of different secondary circuits. The output power of the power amplifier can reach 10W - 50W, which can ensure that the injected signal has sufficient strength in the secondary circuit to accurately detect the insulation performance; The signal injection unit is connected to the secondary circuit through an isolation transformer to achieve electrical isolation, prevent interference with the normal operation of the secondary circuit during the detection process, and also ensure the safety of the detection device. The ratio of the isolation transformer is reasonably selected according to the voltage level and detection requirements of the secondary circuit, generally 1:1 - 1:10, with good insulation performance and frequency response characteristics, can effectively transmit the injection signal, and isolate the DC component and power frequency interference signal in the secondary circuit.

2. A secondary circuit insulation detection device according to claim 1, characterized in that: The end of the liquid spray pipe (13) away from the nozzle (11) is connected to a pressurized tank (14), an air bag (17) is arranged inside the pressurized tank (14), and a one-way valve (18) is arranged on the outer side of the pressurized tank (14) near the end of the air bag (17).

3. A secondary circuit insulation detection device according to claim 1, characterized in that: A fastening ring (9) is sleeved on one end of the mutual inductance coil (8), and a display screen (2) is installed on the insulation tester (1).

4. A secondary circuit insulation detection device according to claim 1, characterized in that: A power connection (3) is plugged into the side of the insulation tester (1), and a grounding wire (4) is provided on one side of the power connection (3).

5. A secondary circuit insulation detection device according to claim 1, characterized in that: A signal line (6) is provided between the current transformer (5) and the insulation tester (1), and two ends of the signal line (6) are respectively plugged into the insulation tester (1) and the current transformer (5).

6. A secondary circuit insulation detection device according to claim 2, characterized in that: The pressurized tank (14) is connected to the handle (10) via threads, and the air bag (17) is fixedly connected to the inner side of the pressurized tank (14).

7. A secondary circuit insulation detection device according to claim 2, characterized in that: One end of the liquid spray pipe (13) is connected to the pressure tank (14), and the other end is connected to the nozzle (11).

8. A secondary circuit insulation detection device according to claim 1, characterized in that: The voltage sampling unit is equipped with high-resolution voltage sensors at the injection end and each detection point of the secondary circuit.

9. A secondary circuit insulation detection device according to claim 1, characterized in that: The voltage acquisition unit is also equipped with a signal conditioning circuit to amplify, filter and perform analog-to-digital conversion on the signal output by the voltage sensor, convert it into a digital signal and transmit it to the subsequent signal processing unit.

10. A secondary circuit insulation detection device according to claim 1, characterized in that: The control processing unit is based on a high-performance microcontroller or digital signal processor and is responsible for the control and data processing of the entire detection device. The control processing unit is also equipped with a communication interface.

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