GIS bus electrical connection area temperature monitoring device and monitoring method thereof

Abstract

The invention relates to a GIS bus electrical connection area temperature monitoring device and a monitoring method thereof.The GIS bus electrical connection area temperature monitoring device comprises a GIS bus, an external device and an internal device, the external device is arranged outside the GIS bus, the internal device is arranged in the GIS bus, and the external device comprises an external acoustic transducer and a signal generator; the internal device comprises an internal electroacoustic transducer, a temperature sensor, a signal modulation circuit and an energy storage capacitor, an electric connection end of the internal electroacoustic transducer is connected with the signal modulation circuit and the energy storage capacitor, the signal modulation circuit is connected with the energy storage capacitor and the temperature sensor, the temperature sensor is arranged on a GIS center conductor of a GIS bus, and the temperature sensor is connected with the energy storage capacitor. The external electric acoustic transducer and the internal electric acoustic transducer are wirelessly connected through ultrasonic waves, and lossless ultrasonic wave transmission is carried out between the external electric acoustic transducer and the internal electric acoustic transducer. Compared with the prior art, the dual functions of energy transmission and signal return are achieved through multiplexing of a single sound wave channel, and power supply difficulty and signal transmission obstacles caused by a GIS closed structure are innovatively overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of GIS temperature detection, and in particular to a GIS busbar electrical connection area temperature monitoring device and a monitoring method thereof. Background Art

[0002] Gas-insulated metal-enclosed switchgear (GIS) is widely used in various high-voltage transmission systems due to its advantages such as small footprint, compact structure, high operational reliability, and easy 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 GIS equipment operation. In actual operation, GIS busbars may experience temperature anomalies due to problems such as poor contact and eccentric force. 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 sharply when current passes through, which can also cause local overheating. In addition, under the long-term influence of multiple factors such as high voltage, strong electric field and temperature, the insulation components gradually age and the insulation performance deteriorates, which can easily cause local discharge and even serious accidents such as short circuits and power outages.

[0003] GIS is an all-metal enclosed structure, with the busbar electrical connection structure located within the metal shielding case. Existing in-situ temperature monitoring technology relies on wired temperature sensing, which requires drilling holes in the metal shielding layer for wiring. This can cause local electric field distortion and the risk of surface discharge, making it difficult to penetrate the shielding case. There are also safety issues with high-voltage insulation to the ground. To achieve online, real-time temperature monitoring of the GIS busbar electrical connection structure, two major technical bottlenecks must be overcome: wireless signal transmission and energy supply for the monitoring device.

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

[0005] Regarding 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 impractical because it requires destroying the metal shielding structure of the GIS and poses the risk of high-voltage discharge to the ground. Conventional wireless transmission methods, including Bluetooth, NFC, and LoRa, all utilize electromagnetic waves and are therefore incompatible with metal shielding structures.

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

[0007] In summary, it is urgent to study a technology for online temperature monitoring of the GIS busbar electrical connection area to break through the problems of wireless signal transmission and device energy supply, so as to make up for the deficiency that conventional detection methods cannot be used for online monitoring of the internal status of GIS equipment. Summary of the Invention

[0008] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a GIS busbar electrical connection area temperature monitoring device and a monitoring method thereof. Through the innovatively designed acoustic wave transmission channel, wireless and reliable power supply to the internal device and wireless and stable transmission of the internal temperature signal to the outside are simultaneously realized, which breakthrough realizes the multiplexing of acoustic wave channels for energy transmission and signal communication, and provides an integrated solution for GIS internal monitoring devices.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] A GIS busbar electrical connection area temperature monitoring device includes a GIS busbar, the GIS busbar includes a shielding cover, a GIS center conductor and a GIS outer wall, the shielding cover is connected to the GIS center conductor, the shielding cover and the GIS center conductor are placed inside the GIS outer wall, the device also includes: an external device and an internal device, the external device is arranged outside the GIS busbar, and the internal device is arranged inside the shielding cover, wherein:

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

[0012] Furthermore, the signal transceiver end of the external electroacoustic transducer is in close contact with the outer wall of the GIS, and the signal transceiver end of the internal electroacoustic transducer is directly opposite to the signal transceiver end 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 the temperature sensor, and the other end is connected to the inverting input of the operational amplifier, the first capacitor is connected between the inverting input and output of the operational amplifier, the output of the operational amplifier is connected to the threshold and trigger ends of the timer, the discharge end of the timer is connected to the inverting input of the operational amplifier, the power supply and reset ends of the timer are connected to the energy storage capacitor, the ground end of the timer is connected to the zero voltage in the GIS bus, the control voltage end of the timer is connected to the zero voltage in the GIS bus through the second capacitor, and the output end 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 end 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.

[0015] Furthermore, the internal device further includes an electric energy management module, and the internal electroacoustic transducer and the signal modulation circuit are connected to the energy storage capacitor via the electric energy management module.

[0016] A method for monitoring the temperature of a GIS busbar electrical connection area is provided, the method being based on the above-mentioned device and comprising:

[0017] Transmitting a first ultrasonic signal into the GIS busbar via an external electroacoustic transducer of an external device;

[0018] receiving the first ultrasonic signal through an internal electroacoustic transducer of the internal device, and converting the first ultrasonic signal into electrical energy and storing it in an 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 busbar 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 using an 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 an external electroacoustic transducer of an external device and the temperature of the electrical connection area of ​​the GIS busbar is obtained by using a 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 obtaining the characteristic frequency pulse signal includes:

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

[0025] According to the frequency, a rectangular wave signal is generated by 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:

[0027]

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

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

[0030] receiving the second ultrasonic signal via an external electroacoustic transducer of the external device;

[0031] filtering out low-frequency and high-frequency noise in the second ultrasonic signal by the filtering module and amplifying the signal;

[0032] Acquiring a second ultrasonic signal that can be observed or processed using a data processing module and a data acquisition module of an external device;

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

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The present invention transmits ultrasonic waves through internal and external electroacoustic transducers in the internal / external device. When the ultrasonic waves are transmitted from the outside to the inside, electrical energy is transmitted through the ultrasonic waves. When the ultrasonic waves are transmitted from the inside to the outside, temperature information is transmitted through the ultrasonic waves. The invention as a whole realizes the dual functions of energy transmission and signal return through the multiplexing of a single acoustic 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 entire 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, thereby ensuring the integrity of the GIS structure.

[0037] 3. The present invention takes into account the transmission efficiency of sound waves within the GIS during ultrasonic transmission. Excessively high sound wave frequencies will lead to significant transmission attenuation, while excessively low sound wave frequencies are susceptible to interference from transformer vibration signals. Therefore, during the energy supply phase of ultrasonic waves transmitting from the outside to the inside, the sound wave frequency range is set within the range of 5kHz-40kHz. To ensure the sound wave signal energy, the signal voltage amplitude is not less than 10V. This not only ensures transmission efficiency, but also avoids the transformer vibration noise frequency band, ensuring signal stability.

[0038] 4. The present invention uses voltage-frequency conversion technology to encode the temperature signal of the electrical contact part of the GIS busbar into the frequency of a characteristic frequency pulse signal, and then converts it into an ultrasonic signal of the same frequency and transmits it outside the GIS busbar. After receiving the ultrasonic wave, the external device can analyze the temperature by observing the waveform or waveform demodulation and analysis, thereby realizing high-precision temperature detection of the electrical contact part of the GIS busbar.

[0039] 5. The voltage-frequency modulation method adopted by the present invention is naturally resistant to electromagnetic interference and is particularly 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 the present invention adopt a standardized modular design and can be installed and deployed without modifying the GIS main structure. Components can also be replaced and redeployed according to different GIS structures. This has strong adaptability. The external device terminal can be placed in the substation control room, and the internal device realizes non-contact energy and signal transmission through acoustic coupling, meeting the requirements of live installation.

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

[0042] 8. The external device of the present invention transmits ultrasonic waves to the internal device for energy transmission. This energy supply process only takes 90s to 120s. Then the energy storage capacitor of the internal device can complete energy storage to power the internal device. After completing the temperature detection and ultrasonic wave transmission process, the internal device enters a dormant state and waits for the next energy supply. This fast energy supply cycle and time-sharing multiplexing mechanism ensures the long-term operation reliability of the system while being highly economical, and is suitable for substation on-site environments. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0044] Figure 2 Flow chart of the method of the present invention;

[0045] Figure 3 Detailed structural diagram of the signal modulation circuit of the present invention;

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

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

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

[0049] In the picture:

[0050] 1-Signal generator, 2-External electroacoustic transducer, 3-Filter 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 center conductor, 13-GIS outer wall, R V1 -Thermistor, R1-first resistor, C1-first capacitor, C2-second capacitor, OP-operational amplifier, NE555D-timer DETAILED DESCRIPTION

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0052] Example 1

[0053] This embodiment intends to disclose a GIS busbar electrical connection area temperature monitoring device, the device is as follows Figure 1 As shown, it specifically includes GIS bus, external devices and internal devices.

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

[0055] The external device is arranged outside the GIS busbar, and the internal device is arranged in the shielding cover 6.

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

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

[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 directly used to achieve both effects, which are generally 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 end 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, and the temperature sensor 8 is placed on the GIS center conductor 12.

[0060] The internal device further includes an electric energy management module 10 , through which the internal electroacoustic transducer 7 and the signal modulation circuit 9 are connected to the energy storage capacitor 11 . The electric energy 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 ultrasonic waves, and there is a wireless connection between the two.

[0062] The signal transceiver end of the inner electroacoustic transducer 7 is directly opposite to the signal transceiver end of the outer electroacoustic transducer 2 , ensuring lossless transmission of ultrasonic waves between the two.

[0063] The signal modulation circuit 9 is specifically as follows Figure 3 As shown, it 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 between 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 working principle of the signal modulation circuit 9 is voltage-frequency conversion, which converts the input voltage signal through an optimized integrator (such as Figure 3 As shown, the signal modulation circuit 9 is composed of a first resistor R1, a first capacitor C1 and an operational amplifier OP) and outputs the signal to a voltage-frequency converter (timer NE555D). After processing, a rectangular wave signal proportional to the input voltage is obtained. In specific implementation, different chips can be used to build circuits to obtain different signal modulation circuits 9. In this embodiment, the signal modulation circuit 9 uses a 555 timer as a signal modulation chip (timer), and the temperature sensor 8 is a thermistor R V1 , thermistor R V1 The resistance value corresponds to the temperature of the busbar electrical connection area, so the frequency of the output signal after passing through the signal conditioning circuit corresponds to the measured temperature.

[0065] The overall operation of this device consists of three stages: energy supply stage, temperature measurement stage and signal return stage. The three stages realize the conversion and transmission of ultrasonic signal-electrical signal-ultrasonic signal.

[0066] During the power supply stage of the external device, the signal generating module outputs an electrical signal of set frequency and amplitude to the external electroacoustic transducer 2. Based on the piezoelectric effect of the piezoelectric chip 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 to the inside of the GIS equipment.

[0067] When the internal electroacoustic transducer receives an ultrasonic signal transmitted from 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 chip 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 the internal device is automatically awakened to enter the temperature measurement phase. The energy supply phase lasts about 90s to 120s.

[0069] Ultrasonic waves used for energy supply take into account the transmission efficiency of sound waves inside GIS. Too high sound wave frequency will lead to significant transmission attenuation, and too low sound wave frequency will be easily interfered by transformer vibration signals. Therefore, the sound wave frequency range during the energy supply stage is 5kHz-40kHz, and to ensure the sound wave signal energy, the signal voltage amplitude should not be less than 10V.

[0070] During the temperature measurement stage, the electric energy stored in the energy storage capacitor 11 in the internal device provides energy for the measurement of the GIS busbar electrical contact area. The temperature of the GIS busbar electrical connection area is accurately collected through the temperature sensor 8, and the collected temperature signal, that is, the resistance value of the temperature sensor 8, is converted into a characteristic frequency pulse signal using the signal modulation circuit 9. This pulse is a pulse electrical signal whose frequency has a deterministic correspondence with the temperature value.

[0071] During the signal feedback process, the signal modulation circuit 9 outputs the characteristic frequency pulse signal to the internal electroacoustic transducer 7, and the internal electroacoustic transducer 7 converts it into a corresponding ultrasonic signal and transmits it to the external device. After the external electroacoustic transducer 2 receives the ultrasonic signal emitted from the internal device, due to the piezoelectric effect of the piezoelectric chip in the external electroacoustic transducer 2, it will output an electrical signal with the same ultrasonic frequency. After the data acquisition module 4 is used to accurately collect the electrical signal in real time, it is input into the data processing module 5. The waveform can be read directly or the signal can be processed and spectrally analyzed to obtain the temperature information of the GIS busbar electrical contact area, thereby realizing online monitoring of the GIS busbar electrical contact area.

[0072] Example 2

[0073] This embodiment intends to disclose a method for monitoring the temperature of the GIS busbar electrical connection area based on the device disclosed in the above embodiment 1. The method steps are as follows: Figure 2 Shown, including:

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

[0075] S2, receiving the first ultrasonic signal through the internal electroacoustic transducer 7 of the internal device, and converting the first ultrasonic signal into electrical energy and storing it in the energy storage capacitor 11 of the internal device;

[0076] S3, when the energy storage capacitor 11 is charged to the operating voltage threshold, the temperature of the GIS busbar 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, receiving the second ultrasonic signal through the external electroacoustic transducer 2 of the external device and obtaining the temperature of the GIS busbar electrical connection area using the data processing module 5 of the external device.

[0079] The process of obtaining the 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 to the frequency of the characteristic frequency pulse signal one by one.

[0081] According to the frequency, a rectangular wave signal is generated by the signal modulation circuit 9 and output as a characteristic frequency pulse signal.

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

[0083]

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

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

[0086] receiving a second ultrasonic wave signal via an external electroacoustic transducer 2 of an external device;

[0087] The filtering module removes low-frequency and high-frequency noise in the second ultrasonic signal and amplifies the signal;

[0088] Acquiring a second ultrasonic signal that can be observed or processed using the data processing module 5 and the data acquisition module 4 of the external device;

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

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

[0091] Example 3

[0092] This embodiment is based on the above-mentioned embodiment 1 and embodiment 2, and discloses an example of a practical application process based on the above-mentioned device and monitoring method.

[0093] When the device is deployed on site, the signal generator 1, external electroacoustic transducer 2 and filter circuit 3 are packaged as a proximal 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 remote system and are placed in the remote control room. The proximal system and the remote system are connected by a shielded signal line to reduce clutter interference. The data acquisition module 4 has multiple signal receiving channels and can simultaneously collect signals output by multiple sets of proximal systems.

[0094] Turn on the signal generator 1, output an electrical signal of preset frequency and amplitude, convert it into an ultrasonic signal through the external electroacoustic transducer 2 and transmit it 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 charged, the signal generator 1 is turned off, and 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 ultrasonic signal emitted from the inside of the GIS cavity by the internal electroacoustic transducer 7 is received by the external electroacoustic transducer 2 outside the GIS cavity and converted into an electrical signal. The electrical signal output by the external electroacoustic transducer 2 is preprocessed by the filter circuit 3 to filter out most of the noise and improve the signal-to-noise ratio. The filter circuit 3 transmits the preprocessed signal to the data processing module 5 via the data acquisition module 4. The signal waveform received by the data processing module 5 is shown in FIG. Figure 4 , whose shape is close to a sine with a period of t0.

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

[0098] The calibrated temperature-frequency curve is related to the type of temperature measuring device selected by the temperature sensor 8. If a thermistor with a positive temperature coefficient is selected, the shape of the calibrated curve can be seen in Figure 6 In this case, the output signal frequency is negatively correlated with the busbar temperature. In another embodiment, the temperature measuring device can be a thermistor or other element with different temperature characteristics according to actual conditions. In this case, the temperature-frequency curve also has a different shape.

[0099] In summary, the present invention utilizes electroacoustic transducers and energy storage devices to transfer energy from the outside of the GIS through sound waves, innovatively solving the limitations of short power supply life and difficulty in replacement in traditional technologies. At the same time, the present invention can achieve high-precision measurement and real-time monitoring of GIS busbar temperature, thereby providing reliable data support for GIS equipment operating status assessment and fault warning. The innovation of the present invention lies in the use of mechanical waves (sound waves) to achieve wireless transmission of energy and information from sensors inside GIS equipment, solving the limitations of traditional power supply and wireless transmission technologies. The present invention can achieve real-time and accurate measurement of GIS busbar temperature, solving the current technical difficulties in 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 such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A GIS busbar electrical connection area temperature monitoring device, comprising a GIS busbar, wherein the GIS busbar comprises a shielding cover, a GIS center conductor, and a GIS outer wall, wherein the shielding cover is connected to the GIS center conductor, and the shielding cover and the GIS center conductor are placed inside the GIS outer wall, characterized in that: The device further comprises: an external device and an internal device, wherein the external device is arranged outside the GIS busbar and the internal device is arranged inside the shielding cover, wherein: The external device includes an external electroacoustic transducer and a signal generator, and the electrical connection end 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 end of the internal electroacoustic transducer is connected to the signal modulation circuit and the energy storage capacitor, and the signal modulation circuit is connected to the energy storage capacitor and the temperature sensor. The temperature sensor is placed on the GIS central conductor. The external electroacoustic transducer and the internal electroacoustic transducer are wirelessly connected via ultrasound, and lossless ultrasonic transmission is performed between the external electroacoustic transducer and the internal electroacoustic transducer.

2. A GIS busbar electrical connection area temperature monitoring device according to claim 1, characterized in that: The signal transceiver end of the outer electroacoustic transducer is in close contact with the outer wall of the GIS, and the signal transceiver end of the inner electroacoustic transducer is directly opposite to the signal transceiver end of the outer electroacoustic transducer.

3. The GIS busbar electrical connection area temperature monitoring device according to claim 1, characterized in that: 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 the temperature sensor, and the other end is connected to the inverting input of the operational amplifier. The first capacitor is connected between the inverting input and output of the operational amplifier. The output of the operational amplifier is connected to the threshold and trigger ends of the timer. The discharge end of the timer is connected to the inverting input of the operational amplifier. The power supply and reset ends of the timer are connected to the energy storage capacitor. The ground end of the timer is connected to the zero voltage point in the GIS bus. The control voltage end of the timer is connected to the zero voltage point in the GIS bus through the second capacitor. The output end of the timer is connected to the internal electroacoustic transducer.

4. The GIS busbar electrical connection area temperature monitoring device 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 end 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.

5. The GIS busbar electrical connection area temperature monitoring device according to claim 1, characterized in that: The internal device further includes an electric energy management module, and the internal electroacoustic transducer and the signal modulation circuit are connected to the energy storage capacitor via the electric energy management module.

6. A method for monitoring the temperature of a GIS busbar electrical connection area, the method being based on the device according to claims 1-5, characterized in that: The method comprises: Transmitting a first ultrasonic signal into the GIS busbar via an external electroacoustic transducer of an external device; receiving the first ultrasonic signal through an internal electroacoustic transducer of the internal device, and converting the first ultrasonic signal into electrical energy and storing it in an energy storage capacitor of the internal device; When the energy storage capacitor is charged to the working voltage threshold, the temperature of the GIS busbar 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 using an 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 an external electroacoustic transducer of an external device and the temperature of the electrical connection area of ​​the GIS busbar is obtained by using a data processing module of the external device.

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

8. A method for monitoring the temperature of a GIS busbar electrical connection area according to claim 6, characterized in that: The process of obtaining the characteristic frequency pulse signal includes: The frequency of the characteristic frequency pulse signal is obtained by using a signal modulation circuit and a temperature sensor, wherein the frequency is mapped to the resistance value of the temperature sensor; According to the frequency, a rectangular wave signal is generated by a signal modulation circuit and output as a characteristic frequency pulse signal.

9. A method for monitoring the temperature of a GIS busbar electrical connection area according to claim 8, 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: Among them, F out is the frequency of the characteristic frequency pulse signal, V in is the input voltage of the signal modulation circuit and thermistor, that is, the output voltage of the energy storage capacitor, R V1 is the resistance of the temperature sensor, R1 is the size of the thermistor in the signal modulation circuit, C1 is the capacitance of the first capacitor in the signal modulation circuit, V CC This is the power supply voltage for the timer chip.

10. A method for monitoring the temperature of a GIS busbar electrical connection area according to claim 6, 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: receiving the second ultrasonic signal via an external electroacoustic transducer of the external device; filtering out low-frequency and high-frequency noise in the second ultrasonic signal by the filtering module and amplifying the signal; Acquiring a second ultrasonic signal that can be observed or processed using a data processing module and a data acquisition module of an external device; By observing the waveform or waveform demodulation and analysis, the characteristic frequency of the second ultrasonic signal is obtained, and compared with the preset frequency-temperature corresponding value to obtain the temperature of the GIS busbar electrical connection area.

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