A surface acoustic wave sensor for monitoring high-voltage GIS equipment and a method of using the same

Abstract

The application discloses a surface acoustic wave sensor for monitoring high-voltage GIS equipment, which comprises a surface acoustic wave sensor delay line, a surface acoustic wave sensor antenna, an air inlet duct, an air outlet duct, a magnetostrictive sensor, a signal transmitting end and a signal receiving end; the surface acoustic wave sensor delay line is connected with the surface acoustic wave sensor antenna and is in communication connection with the signal transmitting end and the signal receiving end through the surface acoustic wave sensor antenna to realize signal transmission; the air inlet duct and the air outlet duct are both connected with the surface acoustic wave sensor delay line; the magnetostrictive sensors are sleeved outside the air inlet duct and the air outlet duct, and the hollow coils of the magnetostrictive sensors arranged at two ends of the surface acoustic wave sensor delay line are oppositely wound and are arranged in a repelling manner with the magnets, so that the sound waves on the magnetostrictive sensors can be mutually offset on the surface acoustic wave sensor under normal circumstances, and the propagation of the sound wave signals loaded with information on the surface acoustic wave sensor is not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-voltage GIS device monitoring, and in particular to a surface acoustic wave sensor for high-voltage GIS device monitoring and a use method thereof. BACKGROUND

[0002] High-voltage gas insulated switch (GIS) has been more and more widely used due to its high operation reliability. With the continuous improvement of the voltage level of the power grid, it is required that the electrical equipment is small in size, reliable in operation and easy to maintain. Gas insulated switchgear is popular among users due to its advantages, and it is necessary to study the method for predicting internal latent faults in order to ensure the safe operation of the gas insulated switchgear and prolong the maintenance cycle as much as possible.

[0003] In gas measurement applications, the gas inlet and outlet are usually designed, and then the surface acoustic wave delay line is designed at the gas inlet and outlet positions to test the gas density through the delay line acoustic wave characteristics. Due to the high sensitivity and anti-adverse condition performance advantages of the surface acoustic wave gas density sensor, its application in the high-voltage equipment field is also being explored. Through experimental research, it is found that one problem in the application of this principle technology in high-voltage GIS equipment is that if the monitoring unit safety appears loose and is not imprisoned, the delay line acoustic wave characteristics will also be affected, and at this time, the output data of the surface acoustic wave sensor alone cannot diagnose whether the abnormality comes from the monitoring unit or the GIS high-voltage equipment inside, which affects the reliability of the entire surface acoustic wave gas density monitoring module. SUMMARY

[0004] The surface acoustic wave sensor for high-voltage GIS device monitoring and the use method thereof provided by the present application solve the problem that if the monitoring unit safety appears loose and is not imprisoned, the delay line acoustic wave characteristics will also be affected, and at this time, the output data of the surface acoustic wave sensor alone cannot diagnose whether the abnormality comes from the monitoring unit or the GIS high-voltage equipment inside, which affects the reliability of the entire surface acoustic wave gas density monitoring module.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a surface acoustic wave sensor for high-voltage GIS device monitoring, comprising a surface acoustic wave sensor delay line, a surface acoustic wave sensor antenna, a gas inlet guide pipe, a gas outlet guide pipe, a magnetostrictive sensor, a signal transmitting end and a signal receiving terminal; the surface acoustic wave sensor delay line is connected with the surface acoustic wave sensor antenna and is in communication connection with the signal transmitting end and the signal receiving terminal through the surface acoustic wave sensor antenna to realize signal transmission; the gas inlet guide pipe and the gas outlet guide pipe are both connected with the surface acoustic wave sensor delay line; the magnetostrictive sensor is sleeved outside the gas inlet guide pipe and the gas outlet guide pipe.

[0006] Preferably, the magnetostrictive sensor comprises a hollow coil and a magnet, the hollow coil is wound on the inlet pipe and the outlet pipe to form a closed loop structure, and the magnet is arranged outside the hollow coil.

[0007] Preferably, the magnet arranged outside the inlet pipe and the magnet arranged outside the outlet pipe are arranged in an opposite structure.

[0008] Preferably, the magnet is in a ring structure.

[0009] Preferably, the magnet is in a semi-ring structure.

[0010] Preferably, the winding direction of the hollow coil wound on the inlet pipe is opposite to that of the hollow coil wound on the outlet pipe.

[0011] Preferably, the surface acoustic wave sensor delay line is a delay line type surface acoustic wave sensor.

[0012] Preferably, the surface acoustic wave sensor delay line is further provided with a gas sensitive sensing film.

[0013] Preferably, the resonance center frequency of the magnetostrictive sensor is 50%-80% of the substrate acoustic velocity of the surface acoustic wave sensor delay line.

[0014] A use method of a surface acoustic wave sensor for monitoring a high-voltage GIS device, characterized in that the method comprises the following steps:

[0015] S1: transmitting an electric signal by using a signal transmitting end;

[0016] S2: receiving the electric signal transmitted in the step S1 by using a surface acoustic wave sensor antenna;

[0017] S3: after the signal is received by the surface acoustic wave sensor antenna, realizing electric-acoustic conversion on a surface acoustic wave sensor delay line, converting the electric signal into an acoustic signal and propagating on a surface acoustic wave sensor substrate;

[0018] S4: the acoustic signal in the step S3 is changed due to the influence of external gas pressure, and the changed acoustic signal becomes an acoustic signal carrying environmental information;

[0019] S5: converting the acoustic signal carrying environmental information into an electric signal and transmitting the electric signal by using the surface acoustic wave sensor antenna;

[0020] S6: receiving the signal in the step S5 by using a signal receiving end and analyzing the signal, and then analyzing the environmental information.

[0021] The present application has the following beneficial effects:

[0022] The magnetostrictive sensor is arranged at both ends of the surface acoustic wave sensor delay line, and the air core coils of the magnetostrictive sensor arranged at both ends of the surface acoustic wave sensor delay line are oppositely wound and arranged in mutual repulsion with the magnet, so that the sound waves on the magnetostrictive sensor can be cancelled out on the surface acoustic wave sensor under normal circumstances, without affecting the propagation of the sound wave signal carrying information on the surface acoustic wave sensor. If the air pipe is broken or the connection is loose, the sound waves generated by the magnetostrictive sensor cannot be cancelled out on the surface acoustic wave sensor, and will be superimposed and transmitted to the signal receiving end together. However, since the resonant frequency of the magnetostrictive sensor and the substrate sound velocity on the surface acoustic wave sensor are different, the signal can be analyzed later, so that only the sound signal carrying environmental information is obtained, and the analysis of the environmental information is carried out, thereby achieving the effect of monitoring the high-voltage GIS device. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structure schematic view of a surface acoustic wave sensor embodiment for monitoring a high-voltage GIS device.

[0024] Figure 2 It is a schematic view of the relationship between the surface acoustic wave sensor antenna and the signal transmitting end and the signal receiving end. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0026] It should be understood that when used in the specification and the appended claims, the terms "comprise" and "include" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or collections thereof.

[0027] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, unless otherwise clearly indicated by the context, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0028] It should be further understood that the term "and / or" used in the present application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0029] The application provides a surface acoustic wave sensor for monitoring high-voltage GIS equipment, which comprises a surface acoustic wave sensor delay line, a surface acoustic wave sensor antenna, an air inlet pipe, an air outlet pipe, a magnetostrictive sensor, a signal transmitting end and a signal receiving end. Figure 1 The surface acoustic wave sensor delay line is connected with the surface acoustic wave sensor antenna and is in communication connection with the signal transmitting end and the signal receiving end through the surface acoustic wave sensor antenna to realize signal transmission; the air inlet pipe and the air outlet pipe are both connected with the surface acoustic wave sensor delay line; the air inlet pipe and the air outlet pipe are both externally sleeved with the magnetostrictive sensor.

[0030] The signal transmitting end and the signal receiving end refer to an external radio electromagnetic signal transmitter and collector independent of the surface acoustic wave sensor; the electromagnetic signal emitted by the transmitter is received by the antenna of the surface acoustic wave sensor to start the surface acoustic wave sensor to generate a surface acoustic wave signal; after the surface acoustic wave signal senses the gas density of the GIS equipment, the surface acoustic wave signal is reflected back to generate an acousto-electric conversion, and then is transmitted to the signal receiving end through the antenna of the surface acoustic wave sensor; the collector of the signal receiving end carries out measurement and analysis.

[0031] Preferably, the magnet arranged on the outer side of the air inlet pipe and the magnet arranged on the outer side of the air outlet pipe are arranged in a repulsion structure.

[0032] Here, the repulsion structure is combined with the hollow coil with opposite directions, and the combination can cancel out the generated sound waves on the surface acoustic wave sensor delay line under normal conditions, so that the signals transmitted through the antenna are all signals carrying only environmental information. When an abnormal condition occurs, i.e. the gas pipe is broken or the connection is loose, the sound waves generated by the magnetostrictive sensor cannot be cancelled out on the surface acoustic wave sensor, but will be superimposed and transmitted to the signal receiving end together. However, since the resonant frequency of the magnetostrictive sensor and the substrate sound velocity on the surface acoustic wave sensor are different, the signals can be analyzed later, so that only the sound signals carrying environmental information are obtained, and the analysis of environmental information is carried out, thereby achieving the effect of monitoring the high-voltage GIS equipment.

[0033] Preferably, the magnet is in a ring structure.

[0034] Preferably, the magnet is in a semi-ring structure.

[0035] Preferably, the winding direction of the hollow coil wound on the air inlet pipe is opposite to that of the hollow coil wound on the air outlet pipe.

[0036] Preferably, the surface acoustic wave sensor delay line is a delay line type surface acoustic wave sensor.

[0037] Preferably, the surface acoustic wave sensor delay line is further provided with a gas sensitive sensing film.

[0038] The gas sensitive sensing film herein is mainly used for detecting the type of gas in the gas inlet pipe and the gas outlet pipe. In this embodiment, the gas in the gas inlet pipe and the gas outlet pipe is SF6, so the gas sensitive sensing film in this embodiment is an SF6 gas sensitive sensing film.

[0039] Preferably, the resonant center frequency of the magnetostrictive sensor is 50%-80% of the acoustic velocity of the substrate on the surface acoustic wave sensor delay line.

[0040] Here, it is to better analyze the signal at the signal receiving end.

[0041] A method for using a surface acoustic wave sensor for monitoring high-voltage GIS equipment, characterized in that it comprises the following steps:

[0042] S1: using a signal transmitting end to transmit an electrical signal;

[0043] S2: receiving the electrical signal transmitted in step S1 through a surface acoustic wave sensor antenna;

[0044] S3: after the signal is received by the surface acoustic wave sensor antenna, the electrical signal is converted into an acoustic signal on the surface acoustic wave sensor delay line and propagates on the surface acoustic wave sensor substrate;

[0045] S4: the acoustic signal in step S3 changes due to the influence of external gas pressure, and the changed acoustic signal becomes an acoustic signal carrying environmental information;

[0046] S5: converting the acoustic signal carrying environmental information into an electrical signal and transmitting it through the surface acoustic wave sensor antenna;

[0047] S6: the signal receiving terminal receives the signal of step S5 and analyzes it, and further analyzes the environmental information.

[0048] The use process and principle of this embodiment will be further described in detail below.

[0049] As Figure 1As shown, in the embodiment, the hollow coil in the magnetostrictive sensor is selected as the EMAT magnetostrictive sensor coil. When the gas pressure or density changes sharply, the gas inlet pipe and the gas outlet pipe wound with the EMAT magnetostrictive sensor play the function of secondary acoustic wave generation, forming a secondary acoustic wave with a large amplitude. The acoustic wave is superimposed on the original test acoustic surface wave to form a signal with a large difference, which can be used to distinguish the vibration caused by the gas pressure or the loosening of the interface. The EMAT magnetostrictive sensor coils are wound on the gas inlet pipe and the gas outlet pipe respectively, and the winding directions are opposite. The two magnets outside the EMAT magnetostrictive sensor coils with opposite winding directions are also arranged in a repelling manner. In this way, under normal circumstances, the acoustic waves on the magnetostrictive sensor can be cancelled out on the acoustic surface wave sensor, and will not affect the propagation of the acoustic wave signal carrying information on the acoustic surface wave sensor. If the gas pipe breaks or the connection loosens, the acoustic wave generated by the magnetostrictive sensor cannot be cancelled out on the acoustic surface wave sensor, and will be superimposed and transmitted to the signal receiving end together. However, since the resonant frequency of the magnetostrictive sensor and the substrate acoustic velocity on the acoustic surface wave sensor are different, it is convenient to analyze the signal later, so as to obtain the acoustic signal carrying only environmental information, and to analyze the environmental information, thereby achieving the effect of monitoring the high-voltage GIS device.

[0050] Under normal circumstances, when the remote signal generator transmits a corresponding signal through radio waves, the signal is received by the acoustic surface wave antenna and converted into an acoustic wave signal. The acoustic wave signal senses the measured gas during the transmission process. Then, the acoustic surface wave sensor delay line obtains a differentiated resonant frequency Δf according to the gas density of the inlet and outlet.

[0051] When the monitored GIS device has high-voltage discharge, the SF6 gas density becomes unstable. At this time, simply reading the Δf data will find that it is extremely unstable. The typical data of the four signal receiving ends is shown in the following table A:

[0052]

[0053] As shown in the table, when the acoustic surface wave sensor itself fails, such as gas pipe rupture or connection loosening, the test data will also change and become unstable. This unstable phenomenon exhibits a high randomness depending on the type of failure, which has some similarity with the gas instability phenomenon caused by GIS internal failure, and it is difficult to distinguish whether the sensor itself fails or the GIS internal failure. This leads to inaccurate information and the possibility of misleading the monitoring personnel.

[0054] When the pressure, velocity and other parameters of the SF6 gas from the outside change, the acoustic waves sensed by the EMATs superimpose on the surface acoustic wave delay line, and the superimposed energy is very significant, and the superimposed energy is zero or close to zero, so at this time, the far-end receives the signal transmitted by the surface acoustic wave sensor and analyzes the state of the SF6 from the GIS inside.

[0055] Similarly, when the surface acoustic wave sensor itself is abnormal, the conductive acoustic wave energy from the EMATs on the gas inlet pipe and the gas outlet pipe side is different (here, the case that the signals received by the EMAT sensors on the gas inlet pipe and the gas outlet pipe are completely the same due to the position of the fault is ignored, even if the signals are completely the same, they may deviate and be detected later, so this step is reasonable), and the difference signal has a resonance frequency of 50%-80% of the acoustic velocity of the surface acoustic wave sensor substrate due to the design of the EMAT, which can be easily analyzed in subsequent comparison. The specific analysis method can be calculated by the difference in amplitude or phase of the high-frequency electric signal converted by the acoustic-electric conversion of the surface acoustic wave interdigital electrode, or by the FFT calculation method, the analysis method and specific process are prior art, and will not be analyzed in detail.

[0056] Therefore, the patent solves the problem of random jump of test data with high similarity caused by SF6 gas density change of high-voltage GIS equipment in field operation and external sensor fault, and realizes the differentiation and diagnosis of external and internal abnormalities of GIS by reasonably designing the EMAT sensor to form a benign EMAT magnetostrictive double-sensor structure at the gas inlet and outlet, which not only considers the measurement of the current gas density, but also further identifies whether the GIS has a discharge phenomenon according to the gas density jitter, thereby improving the function and value of the traditional gas density relay.

[0057] In summary, by arranging the magnetostrictive sensors at both ends of the surface acoustic wave sensor delay line, and oppositely winding the air coils of the magnetostrictive sensors arranged at both ends of the surface acoustic wave sensor delay line and mutually repelling the magnets, the acoustic waves on the magnetostrictive sensors can be cancelled out on the surface acoustic wave sensor under normal circumstances, and the propagation of the acoustic wave signal carrying information on the surface acoustic wave sensor will not be affected. If the gas pipe is broken or the connection is loose, the acoustic waves generated by the magnetostrictive sensors cannot be cancelled out on the surface acoustic wave sensor, and will be superimposed and transmitted to the signal receiving end together. However, since the resonance frequency of the magnetostrictive sensor and the acoustic velocity of the substrate on the surface acoustic wave sensor are different, the signal can be easily analyzed later, so that only the acoustic signal carrying environmental information is obtained, and the environmental information is analyzed, thereby achieving the effect of monitoring the high-voltage GIS equipment.

[0058] The above embodiments are only used to illustrate the technical solutions of the present application, but not intended to limit the present application; even though the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications to the technical solutions recorded in the above embodiments, or make equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the nature of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be included in the scope of the claims and the specification of the present application.

Claims

1. A surface acoustic wave sensor for monitoring high-voltage GIS equipment, characterized in that, It includes a surface acoustic wave sensor delay line, a surface acoustic wave sensor antenna, an air inlet duct, an air outlet duct, a magnetostrictive sensor, a signal transmitter, and a signal receiver. The surface acoustic wave (SAW) sensor delay line is connected to the SAW sensor antenna and communicates with the signal transmitter and signal receiver terminal through the SAW sensor antenna to achieve signal transmission; the air inlet duct and the air outlet duct are both connected to the SAW sensor delay line; the magnetostrictive sensor is sleeved on the outside of the air inlet duct and the air outlet duct. The magnetostrictive sensor includes a hollow coil and a magnet. The hollow coil is wound around the air inlet duct and the air outlet duct to form a closed loop structure. The magnet is located outside the hollow coil. The magnet located outside the air inlet duct and the magnet located outside the air outlet duct are arranged in a mutually exclusive structure. The hollow coil wound around the air inlet duct and the hollow coil wound around the air outlet duct are wound in opposite directions.

2. The surface acoustic wave sensor for monitoring high-voltage GIS equipment according to claim 1, characterized in that, The magnet has a ring structure.

3. The surface acoustic wave sensor for monitoring high-voltage GIS equipment according to claim 1, characterized in that, The magnet has a semi-ring structure.

4. The surface acoustic wave sensor for monitoring high-voltage GIS equipment according to claim 1, characterized in that, The surface acoustic wave sensor delay line is a delay line type surface acoustic wave sensor.

5. A surface acoustic wave sensor for monitoring high-voltage GIS equipment according to claim 4, characterized in that, The surface acoustic wave sensor delay line is also provided with a gas-sensitive thin film.

6. A method of using a surface acoustic wave sensor for monitoring high-voltage GIS equipment as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Use the signal transmitter to transmit electrical signals; S2: Receive the electrical signal transmitted in step S1 through the surface acoustic wave sensor antenna; S3: After the signal is received by the surface acoustic wave sensor antenna, it is converted into an electroacoustic signal on the delay line of the surface acoustic wave sensor, and the electrical signal is converted into an acoustic signal and propagates on the surface acoustic wave sensor substrate. S4: The acoustic signal in step S3 changes due to the influence of external gas pressure, and the acoustic signal that changes here becomes an acoustic signal carrying environmental information. S5: Convert the acoustic signal carrying environmental information into an electrical signal and transmit it through the surface acoustic wave sensor antenna. S6: The signal receiving terminal receives the signal from step S5 and analyzes it to obtain environmental information.

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