GIS / GIL plug unit overheating early warning system

Abstract

The invention belongs to the technical field of high-voltage electrical equipment monitoring, and particularly discloses a GIS / GIL plug unit overheating early warning system which comprises a thin film temperature sensor, a signal conditioning and power management circuit module, a stress wave excitation module, a battery and a stress wave receiving device. The film temperature sensor is used for monitoring the temperature of the electric connection structure of the GIS / GIL plug unit, and the film temperature sensor has different resistances at different temperatures. The signal conditioning and power supply management circuit module is used for converting a resistance signal output by the thin film temperature sensor into a voltage signal, converting the amplified voltage signal into a periodic pulse signal, converting the periodic pulse signal into mechanical vibration and generating a stress wave, and the stress wave receiving device is used for receiving the stress wave and sending the stress wave to the power supply management circuit module. And the stress wave is demodulated to obtain temperature data. According to the invention, reliable transmission of the in-situ temperature information to the outside of the GIS / GIL equipment is completed, and overheating early warning can be effectively carried out on the GIS / GIL plugging unit.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-voltage electrical equipment monitoring, and particularly relates to a GIS / GIL plug-in unit overheating early warning system. BACKGROUND

[0002] Gas insulated transmission equipment (GIS) and gas insulated transmission line (GIL) are widely used in power systems due to their large transmission capacity, low power loss, and small environmental impact. However, key components such as sliding electrical contact are subjected to long-term electrical, thermal, mechanical, and chemical corrosion, which can cause increased contact resistance, local overheating, and even insulation failure, seriously affecting the safe operation of the equipment. Therefore, real-time online monitoring of the internal state of GIS / GIL, especially the electrical contact temperature, is crucial for preventing faults and improving power grid reliability.

[0003] The existing technology for GIS / GIL plug-in unit overheating early warning mainly measures the surface temperature of the GIS shell or the grading sphere to indirectly infer the temperature of the internal electrical connection structure. However, due to the nonlinearity of heat conduction path and the influence of environmental interference, the response sensitivity of the shell temperature to the internal temperature is low, and there is strong time lag. Research shows that there is almost no significant change in the early stage of failure (temperature rise less than 10K), when the contact resistance increases by 30%, the shell temperature rise is only 1K~2K, which is within the error range of existing indirect temperature measurement technology, and it is difficult to be effectively identified. In addition, due to the characteristics of gas heat convection and heat radiation between the electrical connection structure and the shell, the response delay of the shell temperature to the internal fault can be up to tens of minutes, which cannot meet the real-time requirement. Moreover, the metal structure has shielding effect on wired signal transmission and traditional electromagnetic wireless signal transmission, resulting in a technical bottleneck that the signal cannot be effectively transmitted. According to existing fault cases, no related signals indicating failure have been found by external temperature monitoring means before the plug-in unit melting failure occurs. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide a GIS / GIL plug-in unit overheating early warning system.

[0005] The technical scheme of the present application is: a GIS / GIL plug-in unit overheating early warning system, comprising a thin film temperature sensor, a signal conditioning and power management circuit module, a stress wave excitation module, a stress wave receiving device, and a battery. The thin film temperature sensor is used to output corresponding resistance signals according to real-time temperature data of the GIS / GIL plug-in unit electrical connection structure. The signal conditioning and power management circuit module includes a resistance analysis conversion circuit, a signal amplification circuit, and a frequency domain mapping circuit. The resistance analysis conversion circuit is electrically connected with the thin film temperature sensor and is used to convert the resistance signal output by the thin film temperature sensor into a voltage signal; the signal amplification circuit is electrically connected with the resistance analysis conversion circuit and is used to amplify the voltage signal; and the frequency domain mapping circuit is electrically connected with the signal amplification circuit and is used to convert the amplified voltage signal into a periodic pulse signal. The stress wave excitation module is used to convert the periodic pulse signal into mechanical vibration and generate stress waves. The stress wave receiving device is used to receive the stress waves and demodulate the stress waves to obtain temperature data. The battery is used to supply power to the thin film temperature sensor, the signal conditioning and power management circuit module, and the stress wave excitation module.

[0006] Further, the stress wave excitation module is a lead zirconate titanate piezoelectric ceramic.

[0007] Further, the stress wave emission frequency band is 15 kHz to 60 kHz.

[0008] Further, the signal conditioning and power management circuit module further includes a power management circuit, which is electrically connected with the resistance analysis conversion circuit, the signal amplification circuit, and the frequency domain mapping circuit, respectively, and is used to control the operation of the resistance analysis conversion circuit, the signal amplification circuit, and the frequency domain mapping circuit.

[0009] Further, the corresponding resistance value of the thin film temperature sensor changes in the range of 1 kΩ to 2 kΩ, and the measured temperature ranges from 0°C to 200°C.

[0010] Further, the intelligent guide rod further includes a cavity shell, the cavity shell is a cylindrical structure, the signal conditioning and power management circuit module is arranged inside the cavity shell, a lead screw is arranged on one circular side surface, a hexagonal screw is arranged on the other circular side surface, and the thin film temperature sensor is arranged at one end of the lead screw close to the cavity shell.

[0011] Further, the lead screw, the hexagonal screw, and the cylindrical structure are coaxially arranged.

[0012] Further, an insulating and flame-retardant layer is arranged inside the cavity shell.

[0013] Further, the length of the cavity shell is 60 mm to 150 mm.

[0014] Compared with the prior art, the present application has the following advantages: The overheat early warning system provided by the application is based on outputting corresponding resistance signals according to real-time temperature data of the GIS / GIL plug-in unit electric connection structure, processing the resistance signals, converting the measured temperature into mechanical stress waves, wirelessly transmitting the stress wave signals to the stress wave receiving device outside the GIS / GIL device through the metal structure, receiving and analyzing the internal stress wave information, thereby obtaining the temperature information of the electric connection structure in real time, realizing the in-situ real-time wireless monitoring and transmission of the GIS / GIL device electric contact temperature. The overheat early warning system breaks through the technical bottleneck that the metal structure has a shielding effect on wired signal transmission and traditional electromagnetic wireless signal transmission in the GIS / GIL plug-in unit area temperature measurement, and completes the reliable transmission of the in-situ temperature information to the outside of the GIS / GIL device, which can effectively perform overheat early warning on the GIS / GIL plug-in unit. In the overheat early warning system, the thin film temperature sensor is directly attached to the electric connection structure for measurement, and the direct measurement method avoids the interference of gas heat convection and heat radiation, especially can trigger early warning in the early stage of failure, and solves the problem that the prior art cannot identify a small temperature rise within an error range. The stress wave excitation module converts the electrical signal into mechanical vibration, and uses the metal shell of the GIS / GIL device as a propagation medium, which can greatly reduce environmental interference and ensure stable long-distance transmission of the signal in a closed space. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a module diagram of embodiment 1 of the application; Figure 2 is a module diagram of embodiment 2 of the application; Figure 3 is a structural schematic diagram of embodiment 3 of the application; Figure 4 is a structural schematic diagram of an application example of the application; Figure 5 is a structural schematic diagram of an overheat early warning system of the application example; Figure 6 is a bridge circuit of a signal conditioning and power management circuit module of the application example; Figure 7 is a signal amplification circuit and frequency domain mapping circuit of the application example; Figure 8 is a power management circuit of the application example; Figure 9 is a schematic diagram of the position with the strongest pressure of the stress wave excited by each phase at the outer flange obtained by finite element simulation.

[0016] Wherein, 1-film temperature sensor, 2-signal conditioning and power management circuit module, 21-resistance analysis conversion circuit, 22-signal amplification circuit, 23-frequency domain mapping circuit, 24-power management circuit, 3-stress wave excitation module, 4-battery and stress wave receiving device, 51-cavity shell, 52-screw, 53-hexagonal screw. DETAILED DESCRIPTION

[0017] The specific embodiments of the present application will be described below in conjunction with Figures 1 to 9 The specific embodiments of the present application will be described below in conjunction with

[0018] The terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" can explicitly or implicitly include one or more of the features; in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0019] It should be noted that the circuit connections involved in the present application all adopt conventional circuit connection methods and do not involve any innovation.

[0020] Example 1 As Figure 1The illustrated GIS / GIL plug-in unit overheating early warning system comprises a thin film temperature sensor 1, a signal conditioning and power management circuit module 2, a stress wave excitation module 3, a battery and a stress wave receiving device 4. The thin film temperature sensor 1 is used to output a corresponding resistance signal according to the real-time temperature data of the GIS / GIL plug-in unit electrical connection structure. The signal conditioning and power management circuit module 2 comprises a resistance analysis conversion circuit 21, a signal amplification circuit 22 and a frequency domain mapping circuit 23. The resistance analysis conversion circuit 21 is electrically connected with the thin film temperature sensor 1 and is used to convert the resistance signal output by the thin film temperature sensor 1 into a voltage signal; the signal amplification circuit 22 is electrically connected with the resistance analysis conversion circuit 21 and is used to amplify the voltage signal; the frequency domain mapping circuit 23 is electrically connected with the signal amplification circuit 22 and is used to convert the amplified voltage signal into a periodic pulse signal. The stress wave excitation module 3 is used to convert the periodic pulse signal into mechanical vibration and generate stress waves. The battery is used to supply power to the thin film temperature sensor 1, the signal conditioning and power management circuit module 2 and the stress wave excitation module 3. The stress wave receiving device 4 is used to receive stress waves and demodulate the stress waves to obtain temperature data.

[0021] Preferably, the stress wave excitation module 3 is a lead zirconate titanate piezoelectric ceramic.

[0022] Preferably, the stress wave transmission frequency band is 15 kHz-60 kHz.

[0023] Preferably, the corresponding resistance value of the thin film temperature sensor 1 changes in the range of 1 kΩ-2 kΩ, and the measured temperature range is 0℃-200℃.

[0024] Example 2 Different from example 1 is: Preferably, as Figure 2 illustrated, the signal conditioning and power management circuit module 2 further comprises a power management circuit 24, which is electrically connected with the resistance analysis conversion circuit 21, the signal amplification circuit 22 and the frequency domain mapping circuit 23 respectively, and is used to control the operation of the resistance analysis conversion circuit 21, the signal amplification circuit 22 and the frequency domain mapping circuit 23.

[0025] Example 3 The overheating early warning system proposed in example 2 is applied to an intelligent guide rod as Figure 3 illustrated, which further comprises a cavity shell 51, the cavity shell 51 is a cylindrical structure, the signal conditioning and power management circuit module 2 is arranged inside the cavity shell 51; a lead screw 52 is arranged on one circular side surface, a hexagonal screw 53 is arranged on the other circular side surface, and the thin film temperature sensor 1 is arranged at one end of the lead screw 52 close to the cavity shell 51.

[0026] Preferably, the lead screw 52 and the hexagonal screw 53 are coaxially arranged with the cylindrical structure.

[0027] Preferably, the cavity shell 51 is internally provided with an insulating and flame-retardant layer.

[0028] Preferably, the cavity shell 51 has a length of 60mm-150mm.

[0029] Application example As shown in Figure 4 , Figure 5 , the intelligent guide rod proposed in Example 3 is applied in a 110kV three-phase common box GIS. The intelligent guide rod is located in the center conductor of the GIL / GIL-used pot-type insulator and is used for the connection of the center conductor of the GIL / GIL-used pot-type insulator.

[0030] The thin film temperature sensor 1 outputs a corresponding resistance signal according to the real-time temperature data of the GIS / GIL plug-in unit electrical connection structure. The resistance analysis conversion circuit 21 converts the resistance signal output by the thin film temperature sensor 1 into a voltage signal. The signal amplification circuit 22 performs amplification processing on the voltage signal. The frequency domain mapping circuit 23 converts the voltage signal after amplification processing into a periodic pulse signal. The stress wave excitation module 3 converts the periodic pulse signal into mechanical vibration and generates a stress wave. The stress wave is transmitted to the stress wave receiving device 4 with the insulating pot as the medium. The stress wave receiving device 4 receives the stress wave and demodulates the stress wave to obtain temperature data.

[0031] The cavity shell 51 is made of metal, and in this embodiment, aluminum metal is used, with a thickness of 4mm and a length of 100mm. The diameter of the cylindrical structure is 45mm. The insulating and flame-retardant layer inside the cavity shell 51 is prepared by pouring 3MDP420.H epoxy resin material.

[0032] The outer diameter of the shell of the GIL / GIL-used pot-type insulator center conductor is 60mm. The thread of the lead screw 52 is M20, and the length of the hexagonal screw 53 is 15mm. The hexagonal screw 53 precisely fits the inner thread structure size of the GIL / GIL-used pot-type insulator center conductor.

[0033] The size of the signal conditioning and power management circuit module 2 is 35mm*45mm.

[0034] As shown in Figure 6As shown, the resistance signal output by the thin-film temperature sensor 1 is connected to the resistance conversion circuit 21 via a wire. The resistance conversion circuit 21 uses a bridge circuit, which linearly converts the temperature-related resistance value output by the thin-film temperature sensor 1 into a differential voltage signal, which is then input to the signal amplification circuit 22. The resistance conversion circuit 21 includes two bridge arms. One bridge arm consists of resistors R9 and R13, where one end of R9 is connected to the signal power supply VOUT, and the other end is connected to one end of R13, with the other end of R13 connected to ground. The other bridge arm includes resistors R10, R14, and the temperature sensor 1. One end of resistor R10 is connected to the signal power supply VOUT, and the other end is connected to one end of resistor R14, with the other end of R14 connected to one end of the temperature sensor 1, which is also connected to ground. In this structure, the resistance values ​​of R9 and R10 are the same, and the resistance values ​​of R13 and R14 are the same. The connection point between R9 and R13 leads to the negative terminal NH of the bridge differential signal, and the connection point between R10 and R14 leads to the positive terminal PH of the bridge differential signal. In this application example, the resistance values ​​of R9 and R10 are both 22kΩ, and the resistance values ​​of R13 and R14 are both 33kΩ. According to the parameters set in this application example, the output differential voltage signal is 53.6mV at a temperature of 0°C and 106.26MV at a temperature of 200°C.

[0035] like Figure 7 As shown, the signal amplification circuit 22 is a differential discharge circuit that amplifies the bridge output voltage signal, with an amplification factor set to 20. The amplified voltage signal is then input to the frequency domain mapping circuit 23, where it is converted into a periodic pulse signal of a certain frequency.

[0036] In the application example, the parameters of the frequency domain mapping circuit 23 are controlled so that the output frequency is 20 kHz when the temperature is 0℃ and the output frequency is 40 kHz when the temperature is 200℃. The signal amplification circuit 22 is an amplification circuit chip AD8422, and the frequency domain mapping circuit 23 is a V / F conversion chip AD654. Both the amplification circuit chip AD8422 and the V / F conversion chip AD654 are powered by a single power supply. The negative pole NH of the bridge output differential signal is connected to the -IN port of the amplification circuit chip AD8422, and the positive pole PH of the bridge output differential signal is connected to the +IN port of the amplification circuit chip AD8422. The voltage amplification factor is realized by adjusting the resistance R11. The output voltage VF of the amplification circuit chip is connected to the input port +VIN of the V / F conversion chip AD654 through a protection resistor R15. The power supply of the voltage-to-frequency conversion circuit is connected to the circuit power supply VOUT through an inductor L2, and a capacitor C8 is connected in parallel to the ground. The RT terminal of the V / F conversion chip is connected to the signal ground through a current-limiting resistor R12. The two capacitors CT of the chip are connected in series with an integration capacitor C9. By reasonably setting the resistance of R12 and the capacitance value of C9, the internal current of the chip is controlled, different capacitor charging and discharging times are generated, and the adjustment of the voltage-to-frequency conversion slope is realized. An upper pull resistor R8 is set at the FOUT port of the V / F chip to realize the output of the pulse frequency signal.

[0037] As shown in Figure 8 The power management circuit 24 controls most of the system circuit to be in a deep sleep state most of the time, saving system power consumption. In the application example, a pulse is generated by a timer chip every hour, which is input to the steady-state generator to generate a 30s enable signal, so that the power supply chip outputs a 5V supply voltage. The battery uses a high-temperature-resistant lithium battery with a capacity of 1000mAh. Under the control of the power management circuit 24, the static current of the entire system is only 60μA, and it automatically wakes up to work for 30 seconds every 1 hour to complete a complete temperature measurement and signal transmission, and the working current is 8mA. This intermittent working mode makes the system run continuously for more than 1 year under the power supply of a 1000mAh battery, reducing the maintenance frequency and cost.

[0038] In this application example, the power management circuit 24 is powered by a lithium battery, with the power signal being VCC. First, using the TPL5110 timer chip, by setting different control resistors R4, the chip's port 5 outputs a clock pulse signal at regular intervals. This pulse serves as the backend drive signal, output through port 5 and connected to the trigger port of the LTC6993 monostable multivibrator chip. In this application example, the control resistor is set to 1.41kΩ, meaning a millisecond-level time pulse signal is generated every hour. The internal DIV port of the monostable multivibrator forms a voltage divider circuit between the power supply VCC and ground using voltage divider resistors R1 and R3. By adjusting the ratio of R1 and R3, the voltage input to the DIV port is controlled, resulting in different time integration levels for the chip. Port 3 of the chip is connected to a resistor R2 to ground, controlling the internal current. By appropriately setting the DIV integration level and the internal current, the time pulse signal can be broadened into a stable signal with a certain duration. In this application example, R1 is set to 820kΩ, R3 is set to 1000kΩ, corresponding to the chip's internal clock integration level 7. The current control resistor R2 has a resistance of 715kΩ. According to the chip's datasheet, the clock pulse signal can be widened to a steady-state signal of approximately 30 seconds. The chip output is a steady-state signal at a low level, which cannot be used by the downstream signal power circuit. Therefore, this signal is output to the inverter chip TPS613222 for inversion, converting the low level to a high level. Through the above circuit design, a 30-second high-level VOUT signal can be output every hour. This high-level signal is used to power downstream signal conditioning modules.

[0039] In this application example, the stress wave receiving device 4 is arranged at the GIS flange, specifically at the location where the stress waves excited by each phase exert the strongest pressure at the GIS flange. The location of the strongest pressure of the stress waves at the GIS flange is determined based on the finite element simulation results, such as... Figure 9 As shown, the red area at the GIS flange represents the location of the strongest stress wave pressure, based on finite element simulation results. Specifically, the stress wave receiving device 4 employs a commercially available split-type waterproof stress wave receiver sensor, model TCT40-16R. The stress wave receiving device 4 accurately captures internal stress waves, and the received signal spectrum characteristics are highly consistent with those of the transmitting end without distortion, ensuring accurate reproduction of temperature information.

[0040] The specific models of the above electronic components are not specifically specified; any commercially available ordinary products can be selected, as long as they can meet the usage requirements of this invention.

[0041] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above-described specific embodiments are merely examples of the present application and do not limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A GIS / GIL plug-in unit overheating early warning system, characterized in that, The application relates to a temperature sensor for GIS / GIL plug-in units. The temperature sensor comprises a thin-film temperature sensor (1) for outputting a corresponding resistance signal according to real-time temperature data of an electrical connection structure of a GIS / GIL plug-in unit; a signal conditioning and power management circuit module (2) comprising a resistance analysis conversion circuit (21) electrically connected with the thin-film temperature sensor (1) and used for converting the resistance signal output by the thin-film temperature sensor (1) into a voltage signal; a signal amplification circuit (22) electrically connected with the resistance analysis conversion circuit (21) and used for amplifying the voltage signal; and a frequency domain mapping circuit (23) electrically connected with the signal amplification circuit (22) and used for converting the amplified voltage signal into a periodic pulse signal; a stress wave excitation module (3) for converting the periodic pulse signal into mechanical vibration and generating a stress wave; a stress wave receiving device (4) for receiving the stress wave and demodulating the stress wave to obtain temperature data; and a battery for supplying power to the thin-film temperature sensor (1), the signal conditioning and power management circuit module (2) and the stress wave excitation module (3). The stress wave excitation module (3) is a lead zirconate titanate piezoelectric ceramic. The stress wave emission frequency band is 15 kHz to 60 kHz. The signal conditioning and power management circuit module (2) further comprises a power management circuit (24) electrically connected with the resistance analysis conversion circuit (21), the signal amplification circuit (22) and the frequency domain mapping circuit (23) respectively and used for controlling the resistance analysis conversion circuit (21), the signal amplification circuit (22) and the frequency domain mapping circuit (23) to operate. The corresponding resistance value of the thin-film temperature sensor (1) changes in the range of 1 kOmega to 2 kOmega, and the measured temperature ranges from 0 DEG C to 200 DEG C.

2. A GIS / GIL plug-in unit overheating early warning system as claimed in claim 1, characterized in that, The application is applied to an intelligent guide rod, and the intelligent guide rod further comprises a cavity shell (51) in a cylindrical structure, the signal conditioning and power management circuit module (2) is arranged in the cavity shell (51), a lead screw (52) is arranged on one circular side, a hexagonal screw (53) is arranged on the other circular side, and the thin-film temperature sensor (1) is arranged at one end of the lead screw (52) close to the cavity shell (51).

3. A GIS / GIL plug-in unit overheating warning system as claimed in claim 1, wherein, The lead screw (52) and the hexagonal screw (53) are coaxially arranged with the cylindrical structure.

4. A GIS / GIL plug-in unit overheating warning system as claimed in claim 1, wherein, The cavity shell (51) is internally provided with an insulating and flame-retardant layer.

5. A GIS / GIL plug-in unit overheat warning system as claimed in claim 1, wherein, The length of the cavity shell (51) is 60 mm to 150 mm.

6. A GIS / GIL plug-in unit overheating warning system according to any one of claims 1 to 5, characterized in that, ​ 7. A GIS / GIL plug-in unit overheat early warning system as claimed in claim 6, characterized in that, ​ 8. A GIS / GIL plug-in unit overheat early warning system as claimed in claim 6, wherein, ​ 9. A GIS / GIL plug-in unit overheat warning system as claimed in claim 6, wherein, ​

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