A GIS bus electric connection area temperature monitoring device and a monitoring method thereof

Abstract

This invention relates to a temperature monitoring device and method for the electrical connection area of ​​a GIS busbar, comprising a GIS busbar, an external device, and an internal device. The external device is located outside the GIS busbar, and the internal device is located inside the GIS busbar. The external device includes an external electroacoustic transducer and a signal generator. The internal device includes an internal electroacoustic transducer, a temperature sensor, a signal modulation circuit, and an energy storage capacitor. The electrical connection terminal of the internal electroacoustic transducer is connected to the signal modulation circuit and the energy storage capacitor. The signal modulation circuit is connected to the energy storage capacitor and the temperature sensor. The temperature sensor is placed on the central conductor of the GIS busbar. The external and internal electroacoustic transducers are wirelessly connected via ultrasonic waves, and lossless ultrasonic wave transmission occurs between them. Compared with existing technologies, this invention achieves the dual functions of energy transmission and signal feedback through the multiplexing of a single acoustic channel, innovatively overcoming the power supply difficulties and signal transmission obstacles caused by the enclosed structure of GIS.

Description

Technical Field

[0001] This invention relates to the field of GIS temperature detection technology, and in particular to a temperature monitoring device and method for the electrical connection area of ​​a GIS busbar. Background Technology

[0002] Gas-insulated switchgear (GIS) is widely used in various high-voltage power transmission systems due to its advantages such as small footprint, compact structure, high operational reliability, and convenient installation. It is one of the most important primary equipment. As the core component of GIS equipment, the operating status of the GIS busbar directly affects the safety and reliability of the GIS system. In actual operation, GIS busbars may experience abnormal temperature phenomena due to problems such as poor contact and eccentric stress. For example, if the electrical connection structure becomes loose due to poor installation workmanship or long-term operation, the contact area will decrease and the current density will increase dramatically, leading to localized overheating. Furthermore, the insulating components gradually age under the long-term influence of multiple factors such as high voltage, strong electric field, and temperature, resulting in decreased insulation performance and making them prone to partial discharge, and even causing serious accidents such as short circuits and power outages.

[0003] The GIS (Gas Insulated Gate System) is a fully enclosed metal structure, with the busbar electrical connection structure located inside a metal shield. Current in-situ temperature monitoring technology uses wired temperature sensing, requiring perforations in the metal shielding layer for wiring. This can lead to localized electric field distortion and surface discharge risks, and the wiring is difficult to penetrate the shielding, also posing a high-voltage to ground insulation safety issue. To achieve online, real-time temperature monitoring of the GIS busbar electrical connection structure area, it is necessary to overcome two major technical bottlenecks: wireless signal transmission and power supply for the monitoring device.

[0004] Regarding the energy supply of the monitoring device, the monitoring device needs a stable and reliable energy source for long-term operation inside the equipment. Wired power supply is unusable in GIS due to high voltage insulation issues, while conventional battery power supply has problems with short lifespan and difficulty in replacement, making it unsuitable for GIS setup.

[0005] In terms of wireless signal transmission, the shielding effect of metal shielding structures on electromagnetic signals prevents conventional wireless communication technologies from effectively transmitting sensor signals, making real-time data transmission difficult. Furthermore, conventional wired sensing (fiber optic, electrical) is unusable due to the need to disrupt the metal shielding structure of GIS (Gas Insulated Switchgear) and the risk of high-voltage discharge to ground. Conventional wireless transmission methods, including Bluetooth, NFC, and LoRa, all utilize electromagnetic waves and cannot be applied to metal shielding structures.

[0006] Chinese patent CN209181919U discloses a GIS internal contact temperature monitoring system, including an infrared temperature detection device that penetrates and is fixed to the GIS shell. The infrared temperature detection device includes a sealed shell and an infrared temperature measuring element, an information data acquisition board, and a data processing and transmission board disposed within the sealed shell. The sealed shell is used to prevent SF6 gas from escaping from the GIS. This device can directly measure the temperature of the contact using infrared light. However, since it is directly fixed to the GIS shell, the hole can connect the internal space and the external space. Even if the hole is sealed with the infrared temperature detection device, the metal shielding structure of the GIS will still be damaged. It is impossible to solve the signal transmission problem without damaging the function of the GIS itself.

[0007] In summary, there is an urgent need to research an online temperature monitoring technology for the electrical connection area of ​​GIS busbars, and to overcome the problems of wireless signal transmission and device power supply, so as to make up for the shortcomings of conventional detection methods that cannot be used for online monitoring of the internal status of GIS equipment. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a temperature monitoring device and method for the electrical connection area of ​​a GIS busbar. Through an innovatively designed acoustic wave transmission channel, it simultaneously realizes reliable wireless power supply to the internal device and stable wireless transmission of internal temperature signals to the outside. It achieves a breakthrough in the multiplexing of acoustic wave channels for energy transmission and signal communication, providing an integrated solution for GIS internal monitoring devices.

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] A temperature monitoring device for the electrical connection area of ​​a GIS busbar includes a GIS busbar, the GIS busbar comprising a shielding cover, a GIS central conductor, and a GIS outer wall. The shielding cover is connected to the GIS central conductor, and the shielding cover and the GIS central conductor are disposed within the GIS outer wall. The device further includes an external device and an internal device, the external device being disposed outside the GIS busbar, and the internal device being disposed inside the shielding cover.

[0011] The external device includes an external electroacoustic transducer and a signal generator. The electrical connection terminal of the external electroacoustic transducer is connected to the signal generator. The internal device includes an internal electroacoustic transducer, a temperature sensor, a signal modulation circuit, and an energy storage capacitor. The electrical connection terminal of the internal electroacoustic transducer is connected to the signal modulation circuit and the energy storage capacitor. The signal modulation circuit is connected to the energy storage capacitor and the temperature sensor. The temperature sensor is placed on the central conductor of the GIS. The external and internal electroacoustic transducers are wirelessly connected via ultrasound, and lossless ultrasonic transmission occurs between the external and internal electroacoustic transducers.

[0012] Furthermore, the signal transceiver terminals of the external electroacoustic transducer are in close contact with the outer wall of the GIS, and the signal transceiver terminals of the internal electroacoustic transducer are directly opposite the signal transceiver terminals of the external electroacoustic transducer.

[0013] Furthermore, the signal modulation circuit includes a first resistor, a first capacitor, a second capacitor, an operational amplifier, and a timer. One end of the first resistor is connected to a temperature sensor, and the other end is connected to the inverting input of the operational amplifier. The first capacitor is connected across the inverting input and output of the operational amplifier. The output of the operational amplifier is connected to the threshold and trigger terminals of the timer. The discharge terminal of the timer is connected to the inverting input of the operational amplifier. The power supply and reset terminals of the timer are connected to the energy storage capacitor. The ground terminal of the timer is connected to the zero-voltage point in the GIS bus. The control voltage terminal of the timer is connected to the zero-voltage point in the GIS bus through the second capacitor. The output of the timer is connected to the internal electroacoustic transducer.

[0014] Furthermore, the external device also includes a filtering module, a data acquisition module, and a data processing module. The filtering module is connected to the electrical connection terminal of the external electroacoustic transducer, and one end of the data acquisition module is connected to the filtering module, while the other end is connected to the data processing module.

[0015] Furthermore, the internal device also includes a power management module, and the internal electroacoustic transducer and signal modulation circuit are connected to the energy storage capacitor through the power management module.

[0016] A method for monitoring temperature in the electrical connection area of ​​a GIS busbar, the method being based on the aforementioned device, the method comprising:

[0017] The first ultrasonic signal is transmitted into the GIS busbar through an external electroacoustic transducer of an external device.

[0018] The first ultrasonic signal is received by the internal electroacoustic transducer of the internal device, and the first ultrasonic signal is converted into electrical energy and stored in the energy storage capacitor of the internal device.

[0019] When the energy storage capacitor is charged to the working voltage threshold, the temperature of the GIS bus electrical connection area is collected by the temperature sensor and the characteristic frequency pulse signal is obtained by the signal modulation circuit of the internal device.

[0020] The characteristic frequency pulse signal is converted into a second ultrasonic signal of the same frequency by the internal electroacoustic transducer of the internal device, and the second ultrasonic signal is transmitted to the outside of the GIS bus.

[0021] The second ultrasonic signal is received by the external electroacoustic transducer of the external device, and the temperature of the GIS bus electrical connection area is obtained by the data processing module of the external device.

[0022] Furthermore, the frequency of the first ultrasonic wave is 5kHz to 40kHz, and the amplitude is not less than 10V.

[0023] Furthermore, the process of acquiring the characteristic frequency pulse signal includes:

[0024] The frequency of the characteristic frequency pulse signal is obtained using a signal modulation circuit and a temperature sensor, and the frequency is mapped to the resistance value of the temperature sensor.

[0025] Based on the frequency, a rectangular wave signal is generated using a signal modulation circuit and output as a characteristic frequency pulse signal.

[0026] Furthermore, the expression for the relationship between the resistance of the temperature sensor and the frequency of the characteristic frequency pulse signal is as follows:

[0027]

[0028] Among them, F out V is the frequency of the characteristic frequency pulse signal. in R is the input voltage of the signal modulation circuit and the thermistor, i.e., the output voltage of the energy storage capacitor. V1 R1 is the resistance of the temperature sensor, C1 is the value of the thermistor in the signal modulation circuit, and V is the capacitance of the first capacitor in the signal modulation circuit. CC This refers to the power supply voltage for the timer chip.

[0029] Furthermore, the process of obtaining the temperature of the GIS bus electrical connection area using the data processing module of the external device includes:

[0030] The second ultrasonic signal is received by the external electroacoustic transducer of the external device.

[0031] The filtering module filters out low-frequency and high-frequency noise from the second ultrasonic signal and amplifies it.

[0032] The data processing module and data acquisition module of the external device are used to acquire an observable or processable second ultrasonic signal;

[0033] By observing the waveform or performing waveform demodulation and analysis, the characteristic frequency of the second ultrasonic signal is obtained, and compared with the preset frequency-temperature correspondence value, the temperature of the GIS bus electrical connection area is obtained.

[0034] Compared with the prior art, the beneficial effects of the present invention include:

[0035] 1. This invention transmits ultrasonic waves through internal and external electroacoustic transducers in the internal / external devices. When the ultrasonic waves travel from the outside to the inside, electrical energy is transmitted through the ultrasonic waves. When the ultrasonic waves travel from the inside to the outside, temperature information is transmitted through the ultrasonic waves. The invention as a whole achieves the dual functions of energy transmission and signal feedback through the multiplexing of a single sound wave channel, innovatively overcoming the power supply difficulties and signal transmission obstacles caused by the closed structure of GIS.

[0036] 2. In the device of the present invention, the overall external device is placed outside the GIS busbar, and the internal device is placed inside the GIS shielding cover, without causing any damage to the GIS structure, thus ensuring the integrity of the GIS structure.

[0037] 3. In this invention, the transmission efficiency of sound waves within the GIS is taken into consideration during ultrasonic transmission. Excessively high sound wave frequencies will lead to significant transmission attenuation, while excessively low sound wave frequencies are easily interfered with by transformer vibration signals. Therefore, during the power supply stage of ultrasonic waves from the outside to the inside, the sound wave frequency range is set within the range of 5kHz-40kHz. In order to ensure the energy of the sound wave signal, the signal voltage amplitude is not less than 10V, which ensures both transmission efficiency and avoids the frequency band of transformer vibration noise, thus ensuring signal stability.

[0038] 4. This invention uses voltage-frequency conversion technology to encode the temperature signal of the electrical contact part of the GIS bus into the frequency of a characteristic frequency pulse signal, and then converts it into an ultrasonic signal of the same frequency, which is transmitted to the outside of the GIS bus. After receiving the ultrasonic wave, the external device can analyze the temperature by observing the waveform or demodulating and analyzing the waveform, thus realizing high-precision temperature detection of the electrical contact part of the GIS bus.

[0039] 5. The voltage-frequency modulation method used in this invention is naturally resistant to electromagnetic interference, and is especially suitable for the strong electromagnetic environment inside GIS, ensuring the stability and accuracy of the output signal frequency.

[0040] 6. The internal / external devices of this invention adopt a standardized modular design, which can be installed and deployed without modifying the GIS main structure. The components can also be replaced and redeployed according to different GIS structures, making it highly adaptable. The external device terminal can be placed in the substation control room, and the internal device achieves non-contact energy and signal transmission through acoustic coupling, meeting the requirements for live installation.

[0041] 7. Compared with the traditional scheme of separating power supply and communication channels, the present invention significantly simplifies the system structure and reduces installation complexity.

[0042] 8. In this invention, the external device transmits ultrasonic waves to the internal device for energy transfer. This energy supply process only takes 90s to 120s. Afterward, the energy storage capacitor of the internal device can complete the energy storage and power the internal device. After completing the temperature detection and ultrasonic wave transmission process, the internal device enters a sleep state and waits for the next energy supply. This rapid energy supply cycle and time-sharing multiplexing mechanism ensure the reliability of the system's long-term operation while maintaining high economic efficiency, making it suitable for substation field environments. Attached Figure Description

[0043] Figure 1 This is a structural diagram of the device of the present invention;

[0044] Figure 2 This is a flowchart of the method of the present invention;

[0045] Figure 3 This is a detailed structural diagram of the signal modulation circuit of the present invention;

[0046] Figure 4 This is a waveform diagram of the second ultrasonic signal in one embodiment of the present invention;

[0047] Figure 5 This is a waveform diagram of the processed signal obtained in one embodiment of the present invention;

[0048] Figure 6 This is a calibration curve of the output signal frequency and GIS bus temperature in one embodiment of the present invention.

[0049] In the picture:

[0050] 1-Signal generator, 2-External electroacoustic transducer, 3-Filtering circuit, 4-Data acquisition module, 5-Data processing module, 6-Shielding cover, 7-Internal electroacoustic transducer, 8-Temperature sensor, 9-Signal modulation circuit, 10-Power management module, 11-Energy storage capacitor, 12-GIS central conductor, 13-GIS outer wall, R V1 - Thermistor, R1 - First resistor, C1 - First capacitor, C2 - Second capacitor, OP - Operational amplifier, NE555D - Timer Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0052] Example 1

[0053] This embodiment aims to disclose a temperature monitoring device for the electrical connection area of ​​a GIS busbar, the device being as follows: Figure 1 As shown, it specifically includes the GIS busbar, external devices, and internal devices.

[0054] The GIS busbar includes a shield 6, a GIS center conductor 12, and a GIS outer wall 13. The shield 6 is connected to the GIS center conductor 12, and the shield 6 and the GIS center conductor 12 are placed inside the GIS outer wall 13.

[0055] External devices are located outside the GIS busbar, while internal devices are located in shielding cover 6.

[0056] The external device includes an external electroacoustic transducer 2, a signal generator 1, a filter module, a data acquisition module 4, and a data processing module 5. The electrical connection of the external electroacoustic transducer 2 is connected to the signal generator 1 and the filter module. One end of the data acquisition module 4 is connected to the filter module, and the other end is connected to the data processing module 5.

[0057] The signal transceiver of the external electroacoustic transducer 2 is in close contact with the outer wall 13 of the GIS. In this embodiment, the electroacoustic device in the external electroacoustic transducer 2 should be a piezoelectric wafer active sensor (PWAS). By utilizing the piezoelectric effect of the piezoelectric wafer in the piezoelectric wafer active sensor, an electrical signal with the same frequency as the sound wave will be output.

[0058] In this embodiment, the data acquisition device in the data acquisition module 4 can be a data acquisition card, and the data processing module 5 can be a computer, or an oscilloscope can be used to achieve the same effect. It can generally be arranged in the control room of the substation.

[0059] The internal device includes an internal electroacoustic transducer 7, a temperature sensor 8, a signal modulation circuit 9, and an energy storage capacitor 11. The electrical connection terminal of the internal electroacoustic transducer 7 is connected to the signal modulation circuit 9 and the energy storage capacitor 11. The signal modulation circuit 9 is connected to the energy storage capacitor 11 and the temperature sensor 8. The temperature sensor 8 is placed on the GIS center conductor 12.

[0060] The internal device also includes a power management module 10. The internal electroacoustic transducer 7 and the signal modulation circuit 9 are connected to the energy storage capacitor 11 through the power management module 10. The power management module 10 is used to stabilize the output voltage of the energy storage capacitor 11.

[0061] The external electroacoustic transducer 2 and the internal electroacoustic transducer 7 transmit energy and signals via ultrasound, and are wirelessly connected.

[0062] The signal transceiver terminals of the internal electroacoustic transducer 7 and the external electroacoustic transducer 2 are directly opposite each other, ensuring that the ultrasonic waves between the two can be transmitted without loss.

[0063] Signal modulation circuit 9 is specifically as follows Figure 3 As shown, the system includes a first resistor R1, a first capacitor C1, a second capacitor C2, an operational amplifier OP, and a timer NE555D. One end of the first resistor R1 is connected to the temperature sensor 8, and the other end is connected to the inverting input terminal of the operational amplifier OP. The first capacitor C1 is connected across the inverting input terminal and the output terminal of the operational amplifier OP. The output terminal of the operational amplifier OP is connected to the threshold terminal and the trigger terminal of the timer NE555D. The discharge terminal of the timer NE555D is connected to the inverting input terminal of the operational amplifier OP. The power supply terminal and the reset terminal of the timer NE555D are connected to the energy storage capacitor 11. The ground terminal of the timer NE555D is connected to the zero voltage point in the GIS bus. The control voltage terminal of the timer NE555D is connected to the zero voltage point in the GIS bus through the second capacitor C2. The output terminal of the timer NE555D is connected to the internal electroacoustic transducer 7.

[0064] The signal modulation circuit 9 operates on the principle of voltage-to-frequency conversion, converting the input voltage signal through an optimized integrator (such as...). Figure 3 As shown, the signal modulation circuit 9, consisting of a first resistor R1, a first capacitor C1, and an operational amplifier OP, outputs to a voltage-to-frequency converter (timer NE555D). Through processing, a rectangular wave signal proportional to the input voltage is obtained. In specific implementations, different signal modulation circuits 9 can be obtained by using different chips to build the circuit. In this embodiment, the signal modulation circuit 9 uses the 555 timer as the signal modulation chip (timer), and the temperature sensor 8 is a thermistor R... V1 Thermistor R V1 The resistance value corresponds one-to-one with the temperature of the bus electrical connection area, therefore the frequency of the output signal after passing through the signal conditioning circuit corresponds one-to-one with the measured temperature.

[0065] The device operates in three phases: power supply, temperature measurement, and signal feedback. These three phases enable the conversion and transmission of ultrasonic signals back to electrical signals and back to ultrasonic signals.

[0066] During the power supply phase, the signal generation module outputs an electrical signal with a set frequency and amplitude to the external electroacoustic transducer 2. Based on the piezoelectric effect of the piezoelectric crystal in the external electroacoustic transducer 2, the external electroacoustic transducer 2 can generate an ultrasonic signal with the same frequency as the electrical signal and transmit it into the GIS equipment.

[0067] When the internal electroacoustic transducer receives an ultrasonic signal emitted by an external device, the internal electroacoustic transducer 7 can output an electrical signal with the same frequency as the ultrasonic signal due to the piezoelectric effect of the piezoelectric crystal, and output this electrical signal to the energy storage capacitor 11 to charge the energy storage capacitor 11.

[0068] When the capacitor voltage reaches the operating voltage (typical threshold 3.3V), the charging of the energy storage capacitor 11 stops and automatically wakes up the internal device, entering the temperature measurement stage. The power supply stage lasts for about 90s to 120s.

[0069] For the ultrasonic waves used for power supply, considering the transmission efficiency of sound waves inside the GIS, excessively high sound wave frequencies will lead to significant transmission attenuation, while excessively low sound wave frequencies are easily interfered with by transformer vibration signals. Therefore, the sound wave frequency range during the power supply stage is 5kHz-40kHz, and in order to ensure the energy of the sound wave signal, the signal voltage amplitude should not be less than 10V.

[0070] During the temperature measurement stage, the energy stored in the energy storage capacitor 11 in the internal device powers the measurement of the electrical contact area of ​​the GIS busbar. The temperature of the electrical connection area of ​​the GIS busbar is accurately collected by the temperature sensor 8, and the collected temperature signal, i.e. the resistance value of the temperature sensor 8, is converted into a characteristic frequency pulse signal by the signal modulation circuit 9. This pulse is a pulse electrical signal, and its frequency has a deterministic correspondence with the temperature value.

[0071] During signal transmission, the signal modulation circuit 9 outputs a characteristic frequency pulse signal to the internal electroacoustic transducer 7, which then converts it into a corresponding ultrasonic signal and transmits it to an external device. After receiving the ultrasonic signal emitted from the internal device, the external electroacoustic transducer 2 outputs an electrical signal with the same frequency as the ultrasonic wave due to the piezoelectric effect of the piezoelectric crystal in the external electroacoustic transducer 2. The data acquisition module 4 acquires this electrical signal in real time and accurately, and then inputs it into the data processing module 5. The waveform can be read directly, or the signal can be processed and analyzed to obtain the temperature information of the GIS bus electrical contact area, thereby realizing online monitoring of the GIS bus electrical contact area.

[0072] Example 2

[0073] This embodiment aims to disclose a method for monitoring the temperature of the electrical connection area of ​​a GIS busbar, based on the apparatus disclosed in Embodiment 1 above. The method steps are as follows: Figure 2 As shown, it includes:

[0074] S1, the first ultrasonic signal is transmitted into the GIS busbar through the external electroacoustic transducer 2 of the external device;

[0075] S2, the first ultrasonic signal is received through the internal electroacoustic transducer 7 of the internal device, and the first ultrasonic signal is converted into electrical energy and stored in the energy storage capacitor 11 of the internal device.

[0076] S3, when the energy storage capacitor 11 is charged to the working voltage threshold, the temperature of the GIS bus electrical connection area is collected by the temperature sensor 8 and the characteristic frequency pulse signal is obtained by the signal modulation circuit 9 of the internal device.

[0077] S4, using the internal electroacoustic transducer 7 of the internal device to convert the characteristic frequency pulse signal into a second ultrasonic signal of the same frequency, and transmit the second ultrasonic signal to the outside of the GIS bus.

[0078] S5, the external electroacoustic transducer 2 of the external device receives the second ultrasonic signal and the data processing module 5 of the external device obtains the temperature of the GIS bus electrical connection area.

[0079] The process of acquiring a characteristic frequency pulse signal includes:

[0080] The frequency of the characteristic frequency pulse signal is obtained by using the signal modulation circuit 9 and the temperature sensor 8. The resistance value of the temperature sensor 8 corresponds one-to-one with the frequency of the characteristic frequency pulse signal.

[0081] Based on the frequency, a rectangular wave signal is generated using signal modulation circuit 9 and output as a characteristic frequency pulse signal.

[0082] The expression for the relationship between the resistance of temperature sensor 8 and the frequency of the characteristic frequency pulse signal is as follows:

[0083]

[0084] Among them, F out V is the frequency of the characteristic frequency pulse signal. in R is the input voltage of the signal modulation circuit and the thermistor, i.e., the output voltage of the energy storage capacitor. V1 R1 is the resistance of the temperature sensor, C1 is the value of the thermistor in the signal modulation circuit, and V is the capacitance of the first capacitor in the signal modulation circuit. CC This refers to the power supply voltage for the timer chip.

[0085] The process of acquiring the temperature of the GIS bus electrical connection area using the data processing module 5 of the external device includes:

[0086] The second ultrasonic signal is received by the external electroacoustic transducer 2 of the external device.

[0087] The low-frequency and high-frequency noise in the second ultrasonic signal is filtered out by the filtering module and then amplified.

[0088] The data processing module 5 and data acquisition module 4 of the external device are used to acquire an observable or processable second ultrasonic signal;

[0089] By observing the waveform or performing waveform demodulation and analysis, the characteristic frequency of the second ultrasonic signal is obtained, and compared with the preset frequency-temperature correspondence value, the temperature of the GIS bus electrical connection area is obtained.

[0090] Waveform demodulation and analysis can be performed by using methods such as Fourier decomposition or quadrature I / Q demodulation to obtain the characteristic frequency of the electrical signal. In this embodiment, after processing the waveform, the GIS bus temperature information is obtained based on the pre-calibrated curve showing the relationship between the GIS bus temperature and the output signal frequency.

[0091] Example 3

[0092] This embodiment is based on Embodiments 1 and 2 above, and discloses examples of actual application processes based on the above-described device and monitoring method.

[0093] When the device is deployed on site, the signal generator 1, the external electroacoustic transducer 2 and the filter circuit 3 are packaged as a near-end system and placed on the outer wall of the GIS metal cavity. The data acquisition module 4 and the data processing module 5 form a far-end system and are placed in the remote control room. The near-end system and the far-end system are connected by shielded signal lines to reduce noise interference. The data acquisition module 4 has multiple signal receiving channels and can simultaneously acquire signals output by multiple near-end systems.

[0094] The signal generator 1 is turned on and outputs an electrical signal with a preset frequency and amplitude. The signal is converted into an ultrasonic signal by the external electroacoustic transducer 2 and emitted into the GIS cavity. The internal electroacoustic transducer 7 receives the ultrasonic signal and converts it into an electrical signal to charge the energy storage capacitor 11.

[0095] After the energy storage capacitor 11 is fully charged, the signal generator 1 is turned off. The energy storage capacitor 11 supplies power to the temperature sensor 8 and the signal modulation circuit 9. The temperature information of the GIS bus is obtained through the temperature sensor 8, and the temperature information is converted into a square wave signal with a specific frequency f0 through the signal modulation circuit 9. The period of the square wave signal is t0.

[0096] The external electroacoustic transducer 2 receives the ultrasonic signal emitted from the internal electroacoustic transducer 7 outside the GIS cavity and converts it into an electrical signal. The filtering circuit 3 preprocesses the electrical signal output from the external electroacoustic transducer 2, filtering out most of the noise and improving the signal-to-noise ratio. The filtering circuit 3 then transmits the preprocessed signal to the data processing module 5 via the data acquisition module 4. The waveform of the signal received by the data processing module 5 at this time is shown in the figure. Figure 4 Its shape is close to a sine wave with a period of t0.

[0097] Data processing module 5 uses data analysis software to perform Fourier analysis on the electrical signal sent by data acquisition module 4. The final signal waveform is shown in [reference needed]. Figure 5 The main signal is a signal with a specific frequency f0, and the remaining part is noise signal that has not been completely filtered out. According to... Figure 6 The pre-calibrated temperature-frequency curve shown ultimately yields the temperature information of the GIS busbar, with the corresponding temperature of the busbar electrical connection structure area being T0.

[0098] The calibrated temperature-frequency curve depends on the type of temperature sensing device used in temperature sensor 8. If a thermistor with a positive temperature coefficient is used, the shape of the calibrated curve can be found in [reference needed]. Figure 6 At this point, the output signal frequency is negatively correlated with the bus temperature. In another embodiment, the temperature sensing device can be a thermistor or other component with different temperature characteristics, depending on the actual situation, and the temperature-frequency curve will also have different shapes.

[0099] In summary, this invention utilizes electroacoustic transducers and energy storage devices to transmit energy from outside the GIS via sound waves, innovatively overcoming the limitations of traditional technologies such as short power supply lifespan and difficult replacement. Simultaneously, this invention enables high-precision measurement and real-time monitoring of GIS busbar temperature, thus providing reliable data support for GIS equipment operational status assessment and fault early warning. The innovation of this invention lies in using mechanical waves (sound waves) to achieve wireless transmission of energy and information from sensors within the GIS equipment, overcoming the limitations of traditional power supply and wireless transmission technologies. This invention enables real-time and accurate measurement of GIS busbar temperature, solving the current technical challenge of online monitoring of GIS busbar temperature.

[0100] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A temperature monitoring device for the electrical connection area of ​​a GIS busbar, comprising a GIS busbar, wherein the GIS busbar includes a shielding cover, a GIS central conductor, and a GIS outer wall, the shielding cover being connected to the GIS central conductor, and the shielding cover and the GIS central conductor being disposed within the GIS outer wall, characterized in that, The device further includes: an external device and an internal device, wherein the external device is arranged outside the GIS busbar, and the internal device is arranged inside a shielding enclosure. The external device includes an external electroacoustic transducer and a signal generator. The electrical connection terminal of the external electroacoustic transducer is connected to the signal generator. The internal device includes an internal electroacoustic transducer, a temperature sensor, a signal modulation circuit, and an energy storage capacitor. The electrical connection terminal of the internal electroacoustic transducer is connected to the signal modulation circuit and the energy storage capacitor. The signal modulation circuit is connected to the energy storage capacitor and the temperature sensor. The temperature sensor is placed on the central conductor of the GIS. The external and internal electroacoustic transducers are wirelessly connected via ultrasound, and lossless ultrasonic transmission occurs between the external and internal electroacoustic transducers. The signal modulation circuit includes a first resistor, a first capacitor, a second capacitor, an operational amplifier, and a timer. One end of the first resistor is connected to a temperature sensor, and the other end is connected to the inverting input of the operational amplifier. The first capacitor is connected across the inverting input and output of the operational amplifier. The output of the operational amplifier is connected to the threshold and trigger terminals of the timer. The discharge terminal of the timer is connected to the inverting input of the operational amplifier. The power supply and reset terminals of the timer are connected to the energy storage capacitor. The ground terminal of the timer is connected to the zero-voltage point in the GIS bus. The control voltage terminal of the timer is connected to the zero-voltage point in the GIS bus through the second capacitor. The output of the timer is connected to the internal electroacoustic transducer.

2. The temperature monitoring device for the electrical connection area of ​​a GIS busbar according to claim 1, characterized in that, The signal transceiver terminals of the external electroacoustic transducer are in close contact with the outer wall of the GIS, and the signal transceiver terminals of the internal electroacoustic transducer are directly opposite the signal transceiver terminals of the external electroacoustic transducer.

3. The temperature monitoring device for the electrical connection area of ​​a GIS busbar according to claim 1, characterized in that, The external device also includes a filtering module, a data acquisition module, and a data processing module. The filtering module is connected to the electrical connection terminal of the external electroacoustic transducer. One end of the data acquisition module is connected to the filtering module, and the other end is connected to the data processing module.

4. The temperature monitoring device for the electrical connection area of ​​a GIS busbar according to claim 1, characterized in that, The internal device also includes a power management module, and the internal electroacoustic transducer and signal modulation circuit are connected to the energy storage capacitor through the power management module.

5. A method for monitoring temperature in the electrical connection area of ​​a GIS busbar, the method being based on the device described in claim 3, characterized in that, The method includes: The first ultrasonic signal is transmitted into the GIS busbar through an external electroacoustic transducer of an external device. The first ultrasonic signal is received by the internal electroacoustic transducer of the internal device, and the first ultrasonic signal is converted into electrical energy and stored in the energy storage capacitor of the internal device. When the energy storage capacitor is charged to the working voltage threshold, the temperature of the GIS bus electrical connection area is collected by the temperature sensor and the characteristic frequency pulse signal is obtained by the signal modulation circuit of the internal device. The characteristic frequency pulse signal is converted into a second ultrasonic signal of the same frequency by the internal electroacoustic transducer of the internal device, and the second ultrasonic signal is transmitted to the outside of the GIS bus. The second ultrasonic signal is received by the external electroacoustic transducer of the external device, and the temperature of the GIS bus electrical connection area is obtained by the data processing module of the external device.

6. The method for monitoring temperature in the electrical connection area of ​​a GIS busbar according to claim 5, characterized in that, The frequency of the first ultrasonic wave is 5kHz to 40kHz, and the amplitude is not less than 10V.

7. The method for monitoring temperature in the electrical connection area of ​​a GIS busbar according to claim 5, characterized in that, The process of acquiring the characteristic frequency pulse signal includes: The frequency of the characteristic frequency pulse signal is obtained using a signal modulation circuit and a temperature sensor, and the frequency is mapped to the resistance value of the temperature sensor. Based on the frequency, a rectangular wave signal is generated using a signal modulation circuit and output as a characteristic frequency pulse signal.

8. The method for monitoring temperature in the electrical connection area of ​​a GIS busbar according to claim 7, characterized in that, The expression for the relationship between the resistance of the temperature sensor and the frequency of the characteristic frequency pulse signal is as follows: ； in, F out The frequency of the characteristic frequency pulse signal, V in This is the input voltage to the signal modulation circuit and the thermistor, i.e., the output voltage of the energy storage capacitor. R V1 The resistance value of the temperature sensor. R 1 represents the value of the thermistor in the signal modulation circuit. C 1 represents the capacitance value of the first capacitor in the signal modulation circuit. V CC This refers to the power supply voltage for the timer chip.

9. A method for monitoring temperature in the electrical connection area of ​​a GIS busbar according to claim 5, characterized in that, The process of obtaining the temperature of the GIS busbar electrical connection area using the data processing module of the external device includes: The second ultrasonic signal is received by the external electroacoustic transducer of the external device. The filtering module filters out low-frequency and high-frequency noise from the second ultrasonic signal and amplifies it. The data processing module and data acquisition module of the external device are used to acquire an observable or processable second ultrasonic signal; By observing the waveform or performing waveform demodulation and analysis, the characteristic frequency of the second ultrasonic signal is obtained, and compared with the preset frequency-temperature correspondence value, the temperature of the GIS bus electrical connection area is obtained.

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