Electric heating fault early warning device and method for built-in cable joint of explosion-proof box

Abstract

The invention discloses an electric heating fault early warning device and method for a built-in cable joint of an explosion-proof box, and belongs to the technical field of online monitoring and fault diagnosis of high-voltage power equipment. The system comprises a battery box module, an electric heating integrated device body module and an electric heating integrated probe module. And the battery box module is used for supplying power to the electric heating integrated device body. The electric heating integrated device body comprises a battery inversion module, a GPRS module and an MCU module, the battery inversion module generates direct-current voltages of different magnitudes through electric energy provided by the battery box module and supplies power to the GPRS module, the MCU module and the electric heating integrated probe, the MCU module conducts cable connector fault recognition on received data and sends a result to the GPRS module, and the GPRS module sends the result to the MCU module. The GPRS module transmits the data to a remote terminal; and the electric heating integrated probe is used for collecting temperature and space electric field signals. According to the invention, the online monitoring efficiency of the cable joint with the explosion-proof shell is improved, and early warning judgment errors caused by subjective human judgment are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of online monitoring and fault diagnosis of high-voltage electric power equipment, and in particular relates to an explosion-proof box built-in cable joint electric heating fault early warning device and method. Background Art

[0002] Relevant scientific research institutions at home and abroad have conducted a lot of research on cable joint fault monitoring and early warning. Although traditional fault diagnosis methods, such as temperature monitoring and infrared thermal imaging, can detect faults such as joint overheating to a certain extent, they have limited detection capabilities for internal faults. In addition, these methods usually need to be effectively identified after the fault occurs or develops to a certain extent, making it difficult to achieve early warning and timely intervention. In terms of high-voltage cable joint fault diagnosis, the complexity of the cable joint structure and the diversity of the operating environment make fault diagnosis more difficult. Cable joint fault diagnosis also faces difficulties in data acquisition and processing. Due to the complexity of the internal structure of the cable joint and the uncertainty of the operating environment, it is very difficult to obtain accurate and comprehensive fault data. The effectiveness of maintenance measures: Conventional maintenance measures often only focus on the inspection of the appearance and basic performance of the joint, while ignoring the in-depth assessment of the internal state and potential risks of the joint. This superficial cable fault monitoring method is difficult to detect early faults and hidden dangers inside the joint, so it is impossible to take effective measures to repair it in time, resulting in further expansion of the fault.

[0003] Prior art document 1 (CN113686461B) discloses a T-type cable joint self-powered temperature sensor, a cable joint fault detection system and method. However, its disadvantage is that it relies on a single temperature parameter to monitor the fault of the T-type cable joint, while the temperature of the cable is affected by many factors, not just defects. Changes in ambient temperature, cable load current, ventilation conditions, etc. can all cause the cable temperature to change. For example, in a high temperature environment in summer, even if the cable has no defects, its temperature may be high, which can easily lead to misjudgment. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides an explosion-proof box built-in cable joint electric heating fault warning device and method. The device has a simple structure and is easy to install. It uses a low-power method to increase the life of the monitoring module and reduce the impact on the power grid itself. In addition, the temperature sensing unit and the space electric field sensing unit are built into the explosion-proof shell, which can accurately and efficiently identify cable joint faults. The present invention is suitable for the complex on-site implementation environment of the cable well. This method not only improves the efficiency of online monitoring of cable joints with explosion-proof shells, but also reduces the warning judgment error caused by subjective human judgment, which can effectively ensure the safe and stable operation of high-voltage cables.

[0005] The present invention adopts the following technical solution.

[0006] The first aspect of the present invention provides an explosion-proof box built-in cable joint electric heating fault warning device, including a battery box module, an electric heating integrated device body module and an electric heating integrated probe module, including:

[0007] The battery box module is fixed to the surface of the cable body by a cable tie, and is connected to the electric heating device body module through an aviation interface via a power line;

[0008] The main body module of the electric heating device is fixed to the surface of the cable body by a cable tie;

[0009] The electric heating integrated probe module extends into the explosion-proof box, and the plastic shell surface of the electric heating integrated probe module is kept in close contact with the cable body.

[0010] Preferably, the battery box module is connected to the main body module of the electric heating device, and the built-in lithium battery unit and the online energy acquisition unit of the battery box module work together to supply power to the main body module of the electric heating device.

[0011] Preferably, the main body module of the electric and thermal integrated device is connected to the electric and thermal integrated probe module, and includes a battery inverter unit, a GPRS unit and an MCU unit. The battery inverter unit is used to transmit the electric energy provided by the lithium battery unit in the battery box module to the GPRS unit, the MCU unit and the electric and thermal integrated probe module.

[0012] Preferably, the MCU unit is connected to the GPRS unit, and is used to read the electric field and temperature data emitted by the electric heating integrated probe module through the ADC port, perform cable connector fault judgment on the received data according to the set threshold, and send the cable connector fault judgment result to the GPRS unit.

[0013] Preferably, the GPRS unit is connected to a remote terminal and is used to transmit the cable joint fault judgment result and the electric field temperature data to the remote terminal.

[0014] Preferably, the electrothermal integrated probe module comprises a temperature measuring sensor unit and a spatial electric field sensing unit, which are used to collect temperature and spatial electric field signals, and is encapsulated with thermal conductive silicone grease and tightly adhered to the surface of the middle joint on the cable body with the thermal conductive silicone grease.

[0015] A second aspect of the present invention provides an explosion-proof box built-in cable joint electric heating fault early warning method, which is used to operate on the explosion-proof box built-in cable joint electric heating fault early warning device, comprising:

[0016] Use an electric heating integrated probe to collect explosion-proof shell temperature and electric field data;

[0017] The collected temperature and electric field data are transmitted to the main body of the electric heating device, and a warning threshold is set. The cable joint fault judgment result is obtained according to whether the temperature and electric field data meet the warning threshold;

[0018] The cable joint fault judgment result is sent to the remote device for early warning, realizing the electric heating fault early warning of the built-in cable joint of the explosion-proof box.

[0019] Preferably, the temperature sensing unit and the space electric field sensing unit in the integrated electric heating probe cycle between working and sleeping states, entering the working state according to the set sampling interval time to collect and send temperature and electric field data, and remaining in the sleeping state for the rest of the time.

[0020] Preferably, the background of the electric heating device is in a standby-working-sleeping state, which specifically includes:

[0021] Waiting to receive electric field and temperature data in standby mode;

[0022] After receiving the electric field and temperature data, it enters the working state, combines the electric field and temperature data to judge the cable joint fault, and sends the electric field, temperature data and cable joint fault judgment results to the remote terminal;

[0023] After sending the electric field, temperature data and cable joint fault judgment results to the remote terminal, it enters the sleep state and then enters the standby state after a set time interval.

[0024] Preferably, a warning threshold is set. When either the temperature amplitude of the temperature data exceeds 70°C or the electric field amplitude of the electric field data exceeds 0.1 kV / m, the temperature data and the electric field data are considered to meet the warning threshold, and the cable joint is judged to be faulty. The cable joint fault judgment result is sent to the remote device for warning.

[0025] Compared with the prior art, the beneficial effects of the present invention include at least: providing an explosion-proof box built-in cable joint electric heating fault warning device and method, the device has a simple structure and is easy to install, and the life of the monitoring module is improved and the impact on the power grid itself is reduced by adopting a low-power method for the signal acquisition and receiving module; considering the internal state of the joint, by building the cable head electric heating fault warning device into the explosion-proof box, the early fault inside the joint is monitored, the cable joint fault can be accurately and efficiently identified, and effective measures can be taken in time to repair it to prevent the fault from further expanding. The device of the present invention is suitable for the complex on-site implementation environment of the cable well, which not only improves the efficiency of online monitoring of the cable joint with the explosion-proof shell, but also reduces the warning judgment error, which can effectively ensure the safe and stable operation of the high-voltage cable. The electric heating fault warning device proposed by the present invention not only collects the temperature signal of the cable joint, but also collects the electric field signal, which makes up for the defects of the temperature signal being affected by environmental factors, and makes up for the high false alarm rate of cable joint fault monitoring based on temperature parameters alone, so that the monitoring accuracy is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall arrangement of the device of the present invention;

[0027] Figure 2 This is a physical diagram of the device of the present invention;

[0028] Figure 3 It is the physical layout diagram of the explosion-proof box of the present invention;

[0029] Figure 4 It is a schematic diagram of the hardware module of the device of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0031] like Figure 1 As shown, an explosion-proof box built-in cable connector electric heating fault warning device proposed in Example 1 of the present invention includes a battery box module 1, an electric heating integrated device body module 2, and an electric heating integrated probe module 3.

[0032] The battery box module 1 is fixed to the surface of the cable body 8 by a cable tie 4, and is connected to the electric heating device body module 2 by an aviation interface 7 through a power line 6. The electric heating device body module 2 is fixed to the surface of the cable body 8 by a cable tie 4;

[0033] The electric and thermal integrated probe module 3 extends into the explosion-proof box 5, and the plastic shell surface of the electric and thermal integrated probe module 3 is kept in close contact with the cable body 8. If it is far away from the cable, the signal coupling amount will be attenuated.

[0034] like Figure 2 As shown, 1 is a physical picture of the main body module 2 of the electric and thermal integrated device, 2 is a physical picture of the battery box module 1, and 3 is a physical picture of the electric and thermal integrated probe module 3.

[0035] like Figure 3 As shown, 1 is a physical picture of the explosion-proof box 5, 2 is a physical picture of the electric heating integrated device body module 2, and 3 is a physical picture of the cable body 8.

[0036] like Figure 4 As shown, the battery box module 1 is connected to the electric heating device body module 2, used to supply power to the electric heating device body module 2, and is tightly sealed with a metal waterproof box to achieve waterproof and anti-electromagnetic interference effects;

[0037] The battery box module 1 includes a lithium battery unit and an online energy acquisition unit. The built-in lithium battery unit in the battery box module 1 and the online energy acquisition unit work together to fully realize the continuous powered operation of the electric heating integrated device. The online energy acquisition unit includes an online energy acquisition electromagnetic induction coil.

[0038] The design and manufacture of the aviation interface 7 must comply with strict standards and specifications to ensure its performance and reliability in extreme environments. These standards include the ability to withstand special environments such as high temperature, high pressure, earthquake resistance, and waterproofing, and are suitable for the working environment of the cable well.

[0039] like Figure 4 As shown, the electric heating and discharging device body module 2 is connected to the electric heating and discharging probe module 3, and includes a battery inverter unit, a GPRS unit and an MCU unit; the electric heating and discharging device body module 2 is also fixed to the surface of the cable body 8 by a cable tie 4.

[0040] The battery inverter unit includes an inverter and a DC-DC power conversion unit, which generates DC voltages of different magnitudes from the electric energy provided by the lithium battery unit in the battery box module 1 and supplies the DC voltages to the GPRS unit, the MCU unit and the electric and thermal integrated probe module 3;

[0041] The MCU unit is connected to the GPRS unit, and the STM32 core development board of the MCU unit reads the electric field and temperature analog signals of the electric heating integrated probe module 3 through the ADC port, performs cable connector fault judgment on the received data according to the set threshold value to identify whether a cable connector fault occurs, and sends the cable connector fault judgment result to the GPRS unit;

[0042] Among them, in order to improve the performance and accuracy of the ADC port, the ADC design process requires reasonable wiring and grounding.

[0043] The specific design of wiring includes: when designing the PCB, rationally plan the wiring of the ADC to avoid the signal line being too long or parallel to other high-frequency signal lines to reduce crosstalk between signals. At the same time, try to shorten the distance between the ADC and the signal source to reduce signal attenuation.

[0044] The specific grounding design includes that good grounding is the key to ensuring ADC performance. Make sure that the ADC ground pin is well connected to the system ground plane and avoid forming a ground loop. Single-point grounding or multi-layer grounding can be used.

[0045] The GPRS unit is connected to a remote terminal to transmit the cable joint fault judgment result and the electric field temperature data to the remote terminal such as a mobile phone or a computer.

[0046] The electric heating integrated probe module 3 is composed of a temperature sensing unit and a space electric field sensing unit, and is used to collect temperature and space electric field signals. It is encapsulated with thermal conductive silicone grease, and can be tightly attached to the surface of the middle joint on the cable body 8 with the thermal conductive silicone grease. In the present invention, since there is no external power supply, in order to enable the system of the present invention to have a life of 2-3 years and be maintenance-free during operation, the temperature sensing unit and the space electric field sensing unit in the present invention cycle between working and sleeping states, enter the working state according to the set sampling interval time, collect and send temperature and electric field data, and remain in the sleeping state for the rest of the time, that is, the working-sleeping state cycle.

[0047] Among them, the electric field test sensitivity of the electric heating integrated probe module 3 reaches 0.1kV / m and the range reaches 0-100kV / m, and the temperature test sensitivity reaches 0.1℃ and the range reaches -20-100℃, which can meet the needs of cable joint fault monitoring.

[0048] In addition, the device as a whole can reach IP68 waterproof grade, which is suitable for cable well environment. The overall power consumption is 290mW, 0.03mW in low power state, the monitoring and acquisition frequency is dynamically adjustable, the probe is 17mm*10mm, the length is adjustable, and it supports 3-way temperature and electric field strength monitoring; the Saftec water-immersion non-flammable and explosion-proof industrial-grade battery is imported from France, and the operating temperature is -60℃-85℃.

[0049] Embodiment 2 of the present invention provides an explosion-proof box built-in cable joint electric heating fault early warning method, which is used to run in embodiment 1 to provide an explosion-proof box built-in cable joint electric heating fault early warning device, including:

[0050] Step 1: Use the electric heating integrated probe to collect the explosion-proof shell temperature and electric field data;

[0051] The temperature sensing unit and the space electric field sensing unit in the electric heating integrated probe cycle between working and sleeping states. They enter the working state according to the set sampling interval time to collect and send temperature and electric field data, and remain in the sleeping state for the rest of the time.

[0052] Step 2: The collected temperature and electric field data are transmitted to the electric heating device body, and a warning threshold is set. The cable joint fault judgment result is obtained according to whether the temperature and electric field data meet the warning threshold.

[0053] The background of the electric heating device is in standby-working-sleeping state, including:

[0054] Waiting to receive electric field and temperature data in standby mode;

[0055] After receiving the electric field and temperature data, it enters the working state, combines the electric field and temperature data to judge the cable joint fault, and sends the electric field, temperature data and cable joint fault judgment results to the remote terminal;

[0056] After sending the electric field, temperature data and cable joint fault judgment results to the remote terminal, it enters the sleep state and then enters the standby state after a set time interval.

[0057] Set a warning threshold. When the temperature amplitude of the temperature data exceeds 70°C and the electric field amplitude of the electric field data exceeds 0.1kV / m, the temperature data and the electric field data are considered to meet the warning threshold, and the cable joint is judged to be faulty. The cable joint fault judgment result is sent to the remote device for warning.

[0058] Step 3: Send the cable connector fault judgment result to the remote device for early warning, so as to realize the electric heating fault early warning of the built-in cable connector of the explosion-proof box.

[0059] Compared with the prior art, the beneficial effects of the present invention include at least: providing an explosion-proof box built-in cable head electric heating fault warning device, the device has a simple structure and is easy to install. By adopting a low-power method for the signal acquisition and receiving module, the life of the monitoring module is increased and the impact on the power grid itself is reduced; considering the internal state of the joint, by building the cable head electric heating fault warning device into the explosion-proof box, the early fault inside the joint is monitored, the cable joint fault can be accurately and efficiently identified, and effective measures can be taken in time to repair it to prevent the fault from further expanding. The device of the present invention is suitable for the complex on-site implementation environment of the cable well, which not only improves the efficiency of online monitoring of the cable joint with the explosion-proof shell, but also reduces the warning judgment error, which can effectively ensure the safe and stable operation of the high-voltage cable. The electric heating fault warning device proposed by the present invention not only collects the temperature signal of the cable joint, but also collects the electric field signal, which makes up for the defects of the temperature signal being affected by environmental factors, and makes up for the high false alarm rate of cable joint fault monitoring based on temperature parameters alone, so that the monitoring accuracy is significantly improved.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An explosion-proof box built-in cable joint electric heating fault warning device, comprising a battery box module (1), an electric heating integrated device body module (2) and an electric heating integrated probe module (3), characterized in that: The battery box module (1) is fixed to the surface of the cable body (8) by a cable tie (4), and is connected to the electric heating device body module (2) via an aviation interface (7) through a power line (6); The electric heating device body module (2) is fixed to the surface of the cable body (8) by means of a cable tie (4); The electric and thermal integrated probe module (3) extends into the explosion-proof box (5), and the plastic shell surface of the electric and thermal integrated probe module (3) is kept in close contact with the cable body (8).

2. According to claim 1, the explosion-proof box built-in cable joint electric heating fault early warning device is characterized by: The battery box module (1) is connected to the electric heating device body module (2); the battery box module (1) has a built-in lithium battery unit and an online energy acquisition unit that cooperate to supply power to the electric heating device body module (2).

3. According to claim 2, the explosion-proof box built-in cable joint electric heating fault warning device is characterized by: The electric and thermal integrated device body module (2) is connected to the electric and thermal integrated probe module (3), and comprises a battery inverter unit, a GPRS unit and an MCU unit. The battery inverter unit is used to transmit the electric energy provided by the lithium battery unit in the battery box module (1) to the GPRS unit, the MCU unit and the electric and thermal integrated probe module (3).

4. According to claim 3, the explosion-proof box built-in cable joint electric heating fault warning device is characterized by: The MCU unit is connected to the GPRS unit and is used to read the electric field and temperature data emitted by the electric heating integrated probe module (3) through the ADC port, perform cable joint fault judgment on the received data according to a set threshold value, and send the cable joint fault judgment result to the GPRS unit.

5. According to claim 4, the explosion-proof box built-in cable joint electric heating fault warning device is characterized by: The GPRS unit is connected to a remote terminal and is used to transmit the cable joint fault judgment result and the electric field temperature data to the remote terminal.

6. According to claim 1, the explosion-proof box built-in cable joint electric heating fault early warning device is characterized in that: The electrothermal integrated probe module (3) comprises a temperature sensing unit and a spatial electric field sensing unit, and is used to collect temperature and spatial electric field signals. The module is encapsulated with thermal conductive silicone grease and is tightly attached to the surface of the middle joint on the cable body (8) with the thermal conductive silicone grease.

7. A method for early warning of electric heating fault of a cable joint with a built-in explosion-proof box, used to operate in an early warning device for electric heating fault of a cable joint with a built-in explosion-proof box as claimed in any one of claims 1 to 6, comprising: Use an electric heating integrated probe to collect explosion-proof shell temperature and electric field data; The collected temperature and electric field data are transmitted to the main body of the electric heating device, and a warning threshold is set. The cable joint fault judgment result is obtained according to whether the temperature and electric field data meet the warning threshold; The cable joint fault judgment result is sent to the remote device for early warning, realizing the electric heating fault early warning of the built-in cable joint of the explosion-proof box.

8. According to claim 7, a method for early warning of electric heating failure of a cable connector with a built-in explosion-proof box, characterized in that: The temperature sensing unit and the space electric field sensing unit in the electric heating integrated probe cycle between working and sleeping states. They enter the working state according to the set sampling interval time to collect and send temperature and electric field data, and remain in the sleeping state for the rest of the time.

9. According to claim 7, a method for early warning of electric heating failure of a cable connector with a built-in explosion-proof box, characterized in that: The background of the electric heating device is in standby-working-sleeping state, including: Waiting to receive electric field and temperature data in standby mode; After receiving the electric field and temperature data, it enters the working state, combines the electric field and temperature data to judge the cable joint fault, and sends the electric field, temperature data and cable joint fault judgment results to the remote terminal; After sending the electric field, temperature data and cable joint fault judgment results to the remote terminal, it enters the sleep state and then enters the standby state after a set time interval.

10. The method for early warning of electric heating failure of a cable joint with a built-in explosion-proof box according to claim 7, characterized in that: Set a warning threshold. When the temperature amplitude of the temperature data exceeds 70°C and the electric field amplitude of the electric field data exceeds 0.1kV / m, the temperature data and the electric field data are considered to meet the warning threshold, and the cable joint is judged to be faulty. The cable joint fault judgment result is sent to the remote device for warning.

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