A method and device for detecting partial discharge in transformers based on an acoustic coupling ring structure
By using frequency separation of an acoustic coupling ring structure and fiber optic coupling technology, the accuracy problem of partial discharge detection at the transformer outlet was solved, achieving efficient and accurate detection of partial discharge fault types.
Patent Information
- Application Number
- CN202211114465.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-13
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2042-09-13
AI Technical Summary
In existing technologies for detecting partial discharge at transformer outlets, methods based on pulse current and fiber optics are easily affected by external electromagnetic interference and have low signal-to-noise ratios. Furthermore, ultrasonic signals have low energy, making it impossible to accurately detect partial discharge.
An acoustic coupling ring structure is adopted. The first ultrasonic signal from the transformer is received by the ring metal sheet and the ring metal rod and frequency separation is performed. The backscattered light signal is generated by coupling the sensing fiber and the laser. Combined with the ultrasonic measurement system, the partial discharge fault type is detected in real time.
It improves the detection efficiency of partial discharge fault types, broadens the detection bandwidth, eliminates electromagnetic interference, and improves the accuracy of measurement results.
Smart Images
Figure CN115327326B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of partial discharge detection, and in particular to a transformer partial discharge detection method and device based on a sound coupling ring structure. BACKGROUND
[0002] The bushing outlet part of a transformer has the characteristics of large charge density and complex outlet structure, and partial discharge faults are prone to occur at this position, which can damage the insulation of the transformer body and the bushing. Therefore, it is particularly important to carry out partial discharge detection at the outlet part of the transformer.
[0003] At present, the detection methods of partial discharge fault types mainly include detection methods based on pulse current, ultrasonic sensors and optical fiber methods, and a feature database is established based on various partial discharge faults to obtain partial discharge PRPD spectrum and N-V spectrum characteristics through comparative analysis, so as to realize the discrimination of partial discharge fault types. However, the partial discharge fault type detection method based on pulse current and other electrical methods is easily affected by external electromagnetic environment interference, which affects the accuracy of the measurement results and has a low signal-to-noise ratio. The partial discharge fault detection method based on the optical fiber method is limited by factors such as sensor packaging structure and resonance frequency, and the measurement frequency band of the optical fiber ultrasonic sensor is limited, and the ultrasonic signal energy generated by the partial discharge at the outlet part of the transformer is small, and the signal is weak after the transmission and reflection attenuation, so it is impossible to accurately detect the partial discharge condition. SUMMARY
[0004] The present application provides a transformer partial discharge detection method and device based on a sound coupling ring structure, which simplifies the frequency separation process when the transformer sends out a first ultrasonic signal, thereby improving the detection efficiency of the transformer partial discharge fault type.
[0005] To solve the above technical problems, the present application provides a transformer partial discharge detection method based on a sound coupling ring structure, comprising:
[0006] The ring-shaped metal sheet and the ring-shaped metal rod of the sound coupling ring structure receive the first ultrasonic signal sent by the transformer, and perform frequency separation processing on the first ultrasonic signal to obtain a plurality of second ultrasonic signals corresponding to different frequencies, and then conduct each second ultrasonic signal to the sensing optical fiber of the sound coupling ring structure; wherein the second ultrasonic signal corresponds to the frequency one by one.
[0007] The sensing optical fiber receives each second ultrasonic signal and sensing laser emitted by a laser, so that the sensing laser and each second ultrasonic signal are coupled, and each second ultrasonic signal generates a corresponding backscattering light signal.
[0008] Conduct all the backscattering light signals to an ultrasonic measurement system, and detect the partial discharge fault type of the transformer in real time.
[0009] The embodiment of the present application separates the partial discharge ultrasonic signals of different frequencies in the first ultrasonic signal transmitted by the transformer through the annular metal sheet and the annular metal rod of the acoustic coupling annular structure, so as to obtain the second ultrasonic signals corresponding to multiple frequencies, so that the second ultrasonic signals of high frequencies are distributed on the upper part of the inner wall of the acoustic coupling annular structure, and the second ultrasonic signals of low frequencies are distributed on the lower part of the inner wall of the acoustic coupling annular structure, and the signal conducted to the ultrasonic measurement system does not need to be separated in frequency through an additional software algorithm, thereby improving the overall detection efficiency.
[0010] As a preferred solution, the annular metal sheet and the annular metal rod of the acoustic coupling annular structure receive the first ultrasonic signal transmitted by the transformer, and perform frequency separation processing on the first ultrasonic signal to obtain second ultrasonic signals corresponding to multiple frequencies, and then conduct each second ultrasonic signal to the sensing optical fiber of the acoustic coupling annular structure.
[0011] The annular metal sheet and the annular metal rod of the acoustic coupling annular structure receive the first ultrasonic signal conducted through the magnetic suction base of the acoustic coupling annular structure, wherein the first ultrasonic signal is transmitted by the transformer to the acoustic coupling annular structure when partial discharge occurs in the transformer, the annular metal sheet is attached between the upper surface of the magnetic suction base and the lower surface of the main acoustic focusing structure, each annular metal rod is embedded in the inside of the main acoustic focusing structure according to a preset interval, the acoustic coupling annular structure is attached to the transformer riser of the transformer, and the magnetic suction base is composed of a magnetic suction base shell and a neodymium magnet embedded in a groove of the magnetic suction base shell.
[0012] The annular metal sheet and the annular metal rod perform frequency separation processing on the first ultrasonic signal to obtain second ultrasonic signals corresponding to multiple frequencies, and conduct each second ultrasonic signal to the inner surface of the acoustic coupling annular structure, so as to conduct each second ultrasonic signal to the sensing optical fiber attached to the inner surface of the acoustic coupling annular structure.
[0013] The preferred solution of the embodiment of the present application arranges annular metal rods in the inside of the main acoustic focusing structure according to a preset interval, and attaches a layer of annular metal sheet between the upper surface of the magnetic suction base and the lower surface of the main acoustic focusing structure, so as to realize broadband sensitivity enhancement of fiber ultrasonic sensing, thereby widening the detection frequency band of the partial discharge fault type of the transformer.
[0014] As a preferred solution, the backscattered light signals are conducted to an ultrasonic measurement system, and the partial discharge fault type of the transformer is detected in real time.
[0015] The beginning end of the sensing optical fiber is reinforced using an armored optical cable, and the backscattered light signals are conducted to the ultrasonic measurement system through the reinforced beginning end of the sensing optical fiber.
[0016] The corresponding partial discharge frequency spectrum feature is extracted by the ultrasonic measurement system, and the partial discharge frequency spectrum feature is detected in combination with a feature database to obtain the partial discharge fault type of the transformer.
[0017] The feature database includes ultrasonic frequency distribution results corresponding to several partial discharge fault types of the transformer.
[0018] According to the preferred solution of the embodiment of the present application, the frequency decomposition of the first ultrasonic signal and the extraction of the partial discharge frequency spectrum feature are realized by the acoustic coupling ring structure and the ultrasonic measurement system, without the need for feature extraction on a server such as a computer, so that the detection rate of the partial discharge fault type is improved, and the armored optical cable can prevent the optical fiber from being damaged due to long-term exposure to the external environment.
[0019] As a preferred solution, the transformer partial discharge detection method based on the acoustic coupling ring structure further includes:
[0020] The partial discharge frequency spectrum feature and the partial discharge fault type are transmitted to a server in real time through a signal transmission system, and the server is controlled to read and display the partial discharge frequency spectrum feature and the partial discharge fault type in real time.
[0021] The ultrasonic measurement system is arranged in a metal shielding box.
[0022] According to the preferred solution of the embodiment of the present application, the ultrasonic measurement system is placed in the metal shielding box, which can effectively eliminate the interference of other electromagnetic waves in the space on the measurement process, thereby effectively reducing the measurement difficulty and improving the accuracy of the measurement result. In addition, the partial discharge frequency spectrum feature and the partial discharge fault type are transmitted to the server in real time, so that a technician or other user can read the partial discharge frequency spectrum feature and the partial discharge fault type of the transformer in real time through the server.
[0023] As a preferred solution, the transformer partial discharge detection method based on the acoustic coupling ring structure further includes:
[0024] A matching terminal is fused at the end of the sensing optical fiber, and sensing laser emitted by a laser is transmitted to the sensing optical fiber through the end of the sensing optical fiber.
[0025] The preferred scheme of implementing the embodiment of the present application is that the matching terminal is fused at the end of the sensing optical fiber, which can prevent the reflection of the sensing laser, and further improve the detection accuracy.
[0026] To solve the same technical problem, the embodiment of the present application also provides a transformer partial discharge detection device based on an acoustic coupling ring structure, which comprises:
[0027] The signal frequency division module is used for receiving the first ultrasonic signal transmitted by the transformer through the annular metal sheet and the annular metal rods of the acoustic coupling ring structure, performing frequency separation processing on the first ultrasonic signal to obtain a plurality of second ultrasonic signals corresponding to a plurality of frequencies, and then conducting each second ultrasonic signal to the sensing optical fiber of the acoustic coupling ring structure; wherein the second ultrasonic signal corresponds to the frequency one by one.
[0028] The coupling module is used for receiving each second ultrasonic signal and the sensing laser emitted by the laser through the sensing optical fiber, so that the sensing laser and each second ultrasonic signal are coupled, and each second ultrasonic signal corresponding backscattering light signal is generated.
[0029] The detection module is used for conducting all the backscattering light signals to the ultrasonic measurement system, and detecting the partial discharge fault type of the transformer in real time.
[0030] As a preferred scheme, the signal frequency division module specifically comprises:
[0031] The first signal transmission unit is used for receiving the first ultrasonic signal conducted through the magnetic suction base of the acoustic coupling ring structure through the annular metal sheet and a plurality of annular metal rods of the acoustic coupling ring structure; wherein the first ultrasonic signal is transmitted by the transformer to the acoustic coupling ring structure when the partial discharge occurs in the transformer, the annular metal sheet is pasted between the upper surface of the magnetic suction base and the lower surface of the main body acoustic focusing structure, each annular metal rod is inlaid in the inside of the main body acoustic focusing structure according to a preset interval, the acoustic coupling ring structure is attached to the transformer riser of the transformer, and the magnetic suction base is composed of a magnetic suction base shell and a neodymium magnet inlaid in the groove of the magnetic suction base shell.
[0032] The signal frequency division unit is used for performing frequency separation processing on the first ultrasonic signal through the annular metal sheet and the annular metal rods to obtain a plurality of second ultrasonic signals corresponding to a plurality of frequencies, and conducting each second ultrasonic signal to the inner surface of the acoustic coupling ring structure, so as to realize the transmission of each second ultrasonic signal to the sensing optical fiber pasted to the inner surface of the acoustic coupling ring structure.
[0033] As a preferred solution, the detection module specifically comprises:
[0034] A second signal transmission unit is configured to use the armored optical cable to reinforce the start end of the sensing optical fiber, and to conduct all the reinforced backscattered light signals from the start end of the sensing optical fiber to an ultrasonic measurement system.
[0035] A detection unit is configured to extract corresponding partial discharge spectrum features through the ultrasonic measurement system, and to detect the partial discharge spectrum features in combination with a feature database to obtain a partial discharge fault type of the transformer, wherein the feature database comprises ultrasonic frequency distribution results corresponding to several partial discharge fault types of the transformer.
[0036] As a preferred solution, the transformer partial discharge detection device based on the acoustic coupling ring structure further comprises:
[0037] A first transmission module is configured to transmit the partial discharge spectrum features and the partial discharge fault type to a server in real time through a signal transmission system, and to control the server to read and display the partial discharge spectrum features and the partial discharge fault type in real time, wherein the ultrasonic measurement system is arranged in a metal shielding box.
[0038] As a preferred solution, the transformer partial discharge detection device based on the acoustic coupling ring structure further comprises:
[0039] A second transmission module is configured to fuse and match a terminal at the end of the sensing optical fiber, and to transmit sensing laser emitted by a laser to the sensing optical fiber through the end of the sensing optical fiber. BRIEF DESCRIPTION OF DRAWINGS
[0040] Figure 1 FIG. 1 is a flowchart of a transformer partial discharge detection method based on an acoustic coupling ring structure according to an embodiment of the present application;
[0041] Figure 2 FIG. 2 is a cross-sectional schematic view of an acoustic coupling ring structure according to the embodiment of the present application;
[0042] Figure 3 FIG. 3 is a cross-sectional schematic view of a combination of a magnetic base and a ring-shaped metal sheet according to the embodiment of the present application;
[0043] Figure 4 FIG. 4 is a structural schematic view of a transformer partial discharge detection device based on an acoustic coupling ring structure according to the embodiment of the present application. DETAILED DESCRIPTION
[0044] With reference to the drawings and embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.
[0045] Embodiment one:
[0046] Please refer to Figure 1 The method comprises steps S1, S2 and S3, and each step is specifically as follows:
[0047] Step S1, the first ultrasonic signal transmitted by the transformer is received through the annular metal sheet and the annular metal rod of the acoustic coupling annular structure, and the first ultrasonic signal is subjected to frequency separation processing to obtain a plurality of second ultrasonic signals corresponding to frequencies, and then each second ultrasonic signal is conducted to the sensing optical fiber of the acoustic coupling annular structure; wherein the second ultrasonic signal corresponds to the frequency one by one.
[0048] As a preferred solution, step S1 comprises steps S11 and S12, and each step is specifically as follows:
[0049] Step S11, the first ultrasonic signal conducted by the magnetic suction base of the acoustic coupling annular structure is received through the annular metal sheet and the plurality of annular metal rods of the acoustic coupling annular structure; wherein the first ultrasonic signal is transmitted by the transformer to the acoustic coupling annular structure when the partial discharge occurs in the interior of the transformer, the annular metal sheet is pasted between the upper surface of the magnetic suction base and the lower surface of the main body acoustic focusing structure, each annular metal rod is inlaid in the interior of the main body acoustic focusing structure according to a preset interval, the acoustic coupling annular structure is attached to the transformer riser of the transformer, and the magnetic suction base is composed of a magnetic suction base shell and a neodymium magnet inlaid in the groove of the magnetic suction base shell.
[0050] Step S12, the first ultrasonic signal is subjected to frequency separation processing through the annular metal sheet and the annular metal rod to obtain a plurality of second ultrasonic signals corresponding to frequencies, and each second ultrasonic signal is conducted to the inner surface of the acoustic coupling annular structure to realize the transmission of each second ultrasonic signal to the sensing optical fiber pasted to the inner surface of the acoustic coupling annular structure; wherein the second ultrasonic signal of high frequency is distributed on the upper part of the inner wall of the acoustic coupling annular structure, and the second ultrasonic signal of low frequency is distributed on the lower part of the inner wall of the acoustic coupling annular structure.
[0051] It should be noted that please refer to Figure 2The acoustic coupling ring structure in the embodiment comprises a main acoustic focusing structure 1, a ring-shaped metal rod 2, a ring-shaped metal sheet 3, a magnetic base 9 composed of a magnetic base shell 4 and a neodymium magnet 5, and a sensing optical fiber 6.
[0052] The main acoustic focusing structure 1 is a ring structure made of polyurethane material, the cross section of which is an equilateral triangle with a side length of 5 cm, an inner radius of 15 cm, and an outer radius of 20 cm. Then, the sensing optical fiber 6 is uniformly pasted on the inner surface of the main acoustic focusing structure 1 using acrylic modified epoxy resin as an adhesive, with a spacing of 1 mm between adjacent optical fibers and 30 turns of winding. Meanwhile, in the interior of the main acoustic focusing structure 1, the ring-shaped metal rod 2 made of stainless steel with a cross-sectional radius of 3 cm is uniformly arranged every 1 cm along the perpendicular of the equilateral triangle of the cross section, and the gap between the ring-shaped metal rod 2 and the polyurethane material is filled with epoxy resin. On the bottom surface of the main acoustic focusing structure 1, a ring-shaped metal sheet 3 made of stainless steel is attached using epoxy resin, with an inner radius of 15 cm, an outer radius of 20 cm, and a thickness of 1 mm, so as to broaden the detection frequency band to 20 kHz-200 kHz and achieve wideband sensitivity of optical fiber ultrasonic sensing. In addition, a ring-shaped recess with an inner radius of 16 cm, an outer radius of 19 cm, and a depth of 4 mm is opened on the bottom surface of the ring-shaped stainless steel structure with an inner radius of 15 cm, an outer radius of 20 cm, and a thickness of 5 mm, thereby forming a magnetic base shell 4, and the neodymium magnet 5 is embedded in the ring-shaped recess to form a magnetic base 9. Then, please refer to Figure 3 (a) and Figure 3 (b), respectively, three fixed screw holes 8 arranged in an equilateral triangle are opened at the corresponding positions of the magnetic base 9 and the ring-shaped metal sheet 3, and the magnetic base 9 and the ring-shaped metal sheet 3 are fixed by screws, which can ensure that the acoustic coupling ring structure with the embedded neodymium magnet 5 is firmly pasted on the surface of the transformer and improve the ultrasonic transmission efficiency.
[0053] In addition, in order to ensure the resolution accuracy of the ultrasonic frequency, the main acoustic focusing structure 1, the ring-shaped metal rod 2, the ring-shaped metal sheet 3, and the magnetic base 9 all need to be subjected to high-precision flat polishing treatment to ensure that the surface unevenness or depression is not more than 0.01 mm.
[0054] In step S2, the sensing optical fiber is used to receive each second ultrasonic signal and sensing laser emitted by the laser to couple the sensing laser and each second ultrasonic signal, and generate a backscattering light signal corresponding to each second ultrasonic signal.
[0055] As a preferred solution, the transformer partial discharge detection method based on the acoustic coupling ring structure provided by the embodiment of the present application further comprises step S4, which is specifically as follows:
[0056] Step S4, please refer toFigure 2 A matching terminal 7 is fused to the end of the sensing optical fiber 6, and the sensing laser emitted by the laser is transmitted to the sensing optical fiber through the end of the sensing optical fiber.
[0057] It should be noted that the matching terminal 7 is a cylindrical device with a length of 5 mm and a radius of 0.5 mm made of silica, and the doping ratio of the silica is controlled and adjusted during the manufacturing process to ensure that the difference between the refractive index of the matching terminal 7 and the sensing optical fiber 6 is less than 5%, thereby ensuring the detection accuracy of the acoustic coupling ring structure. One end of the matching terminal 7 is fused to the sensing optical fiber 6, and the other end is coated with light-absorbing paint to absorb the sensing laser and prevent laser reflection from affecting the detection effect.
[0058] Step S3, all backscattered light signals are transmitted to the ultrasonic measurement system, and the partial discharge fault type of the transformer is detected in real time.
[0059] In this embodiment, the ultrasonic measurement system is a φ-OTDR (Phase-sensitive Optical Time Domain Reflectometry) system.
[0060] As a preferred solution, step S3 includes step S31 and step S32, which are as follows:
[0061] Step S31, using an armored cable, reinforcing the beginning of the sensing optical fiber, and transmitting all backscattered light signals through the reinforced beginning of the sensing optical fiber to the ultrasonic measurement system.
[0062] Step S32, demodulation and pattern recognition are performed by the ultrasonic measurement system to extract the corresponding partial discharge spectral characteristics, and the partial discharge spectral characteristics are detected in combination with a feature database to obtain the partial discharge fault type of the transformer; wherein the feature database includes ultrasonic frequency distribution results corresponding to several types of transformer partial discharge fault types.
[0063] As a preferred solution, the transformer partial discharge detection method based on the acoustic coupling ring structure provided by the embodiment of the present application further includes step S5, which is as follows:
[0064] Step S5, the partial discharge spectral characteristics and the partial discharge fault type are transmitted to the server in real time through the signal transmission system, and the server is controlled to read and display the partial discharge spectral characteristics and the partial discharge fault type in real time; wherein the ultrasonic measurement system is arranged in a metal shielding box made of stainless steel, the metal shielding box is arranged beside the transformer to be measured and grounded, and the size of the metal shielding box can be adjusted adaptively according to the size of the ultrasonic measurement system and other actual conditions.
[0065] In the embodiment, the metal shielding box has a box length of 45 cm, a box width of 45 cm, a box height of 70 cm, and a box wall thickness of 5 mm, and two openings with a radius of 1 cm are left on the box for leading in the sensing optical fiber 6 and leading out the data line, and the data line led out by the metal shielding box is connected to the signal transmission system to realize data transmission between the ultrasonic measurement system and the acoustic coupling ring structure and between the ultrasonic measurement system and the signal transmission system. When the ultrasonic measurement system outputs data such as partial discharge frequency spectrum characteristics and partial discharge fault type, the first optical transceiver of the signal transmission system converts the received electrical signal into an optical signal, then transmits the optical signal to the second optical transceiver through the transmission optical fiber, so that the second optical transceiver converts the optical signal into an electrical signal, and transmits the electrical signal to the server such as a computer through the data line connected between the second optical transceiver and the server such as a computer, so that the server such as a computer can read and display the partial discharge frequency spectrum characteristics and the partial discharge fault type in real time.
[0066] It should be noted that the ultrasonic measurement system can be connected to multiple acoustic coupling ring structures at the same time, and the multiple acoustic coupling ring structures can be arranged at different positions on the surface of the transformer riser to measure ultrasonic signals at different measuring points.
[0067] Please refer to Figure 4 A structure diagram of a transformer partial discharge detection device based on an acoustic coupling ring structure is provided for the embodiment of the present application, which comprises a signal frequency division module M1, a coupling module M2, and a detection module M3, and each module is as follows:
[0068] The signal frequency division module M1 is used to receive a first ultrasonic signal transmitted by the transformer through the annular metal sheet and the annular metal rod of the acoustic coupling ring structure, and perform frequency separation processing on the first ultrasonic signal to obtain a plurality of second ultrasonic signals corresponding to different frequencies, and then conduct each second ultrasonic signal to the sensing optical fiber of the acoustic coupling ring structure; wherein the second ultrasonic signal corresponds to one frequency.
[0069] The coupling module M2 is used to receive each second ultrasonic signal and sensing laser emitted by a laser through the sensing optical fiber, so that the sensing laser and each second ultrasonic signal are coupled to generate a backscattering light signal corresponding to each second ultrasonic signal.
[0070] The detection module M3 is used to conduct all backscattering light signals to an ultrasonic measurement system, and detect a partial discharge fault type of the transformer in real time.
[0071] As a preferred scheme, the signal frequency division module M1 specifically comprises a first signal transmission unit 11 and a signal frequency division unit 12, and each unit is as follows:
[0072] The first signal transmission unit 11 is configured to receive a first ultrasonic signal conducted by a magnetic suction base of the acoustic coupling annular structure through annular metal sheets and a plurality of annular metal rods of the acoustic coupling annular structure; the first ultrasonic signal is transmitted by the transformer to the acoustic coupling annular structure when partial discharge occurs in the transformer; the annular metal sheets are attached between the upper surface of the magnetic suction base and the lower surface of the main acoustic focusing structure; the annular metal rods are inlaid in the interior of the main acoustic focusing structure according to a preset interval; the acoustic coupling annular structure is attached to the transformer riser of the transformer; and the magnetic suction base is composed of a magnetic suction base shell and a neodymium magnet inlaid in a groove of the magnetic suction base shell.
[0073] The signal frequency division unit 12 is configured to perform frequency separation processing on the first ultrasonic signal through the annular metal sheets and the annular metal rods to obtain a plurality of second ultrasonic signals corresponding to different frequencies, and conduct each second ultrasonic signal to the inner surface of the acoustic coupling annular structure to realize the transmission of each second ultrasonic signal to the sensing optical fiber attached to the inner surface of the acoustic coupling annular structure.
[0074] As a preferred solution, the detection module M3 specifically includes a second signal transmission unit 31 and a detection unit 32, and each unit is specifically as follows:
[0075] The second signal transmission unit 31 is configured to use the armored cable to reinforce the start end of the sensing optical fiber, and conduct all backscattered light signals to the ultrasonic measurement system through the reinforced start end of the sensing optical fiber.
[0076] The detection unit 32 is configured to extract the corresponding partial discharge spectral characteristics through the ultrasonic measurement system, and detect the partial discharge spectral characteristics in combination with a feature database to obtain the partial discharge fault type of the transformer; the feature database includes ultrasonic frequency distribution results corresponding to a plurality of partial discharge fault types of the transformer.
[0077] As a preferred solution, please refer to Figure 4 The transformer partial discharge detection device based on the acoustic coupling annular structure provided by the embodiment of the present application further includes a first transmission module M4, which is specifically as follows:
[0078] The first transmission module M4 is configured to transmit the partial discharge spectral characteristics and the partial discharge fault type to the server in real time through the signal transmission system, and control the server to read and display the partial discharge spectral characteristics and the partial discharge fault type in real time; the ultrasonic measurement system is arranged in the metal shielding box.
[0079] As a preferred solution, please refer to Figure 4 The transformer partial discharge detection device based on the acoustic coupling annular structure provided by the embodiment of the present application further includes a second transmission module M5, which is specifically as follows:
[0080] The second transmission module M5 is configured to fuse a matching terminal at the end of the sensing optical fiber, and transmit the sensing laser emitted by the laser to the sensing optical fiber through the end of the sensing optical fiber.
[0081] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process of the above-described device can refer to the corresponding process in the foregoing method embodiments, which will not be described here.
[0082] Compared with the prior art, the embodiments of the present application have the following beneficial effects:
[0083] The present application provides a transformer partial discharge detection method and device based on a sound coupling ring structure, which adopts a sound coupling ring structure to better converge the first ultrasonic signal sent by the transformer in the ring to improve the capture effect of the ultrasonic signal, and separates the partial discharge ultrasonic signals of different frequencies in the first ultrasonic signal through the ring-shaped metal sheet and the ring-shaped metal rod of the sound coupling ring structure to obtain second ultrasonic signals corresponding to multiple frequencies, so that the second ultrasonic signals of high frequencies are distributed on the upper part of the inner wall of the sound coupling ring structure, and the second ultrasonic signals of low frequencies are distributed on the lower part of the inner wall of the sound coupling ring structure, so as to facilitate the subsequent collection and processing of signals of different frequencies, instead of increasing additional software algorithms to realize the frequency separation of the signals conducted to the ultrasonic measurement system, thereby improving the efficiency of the partial discharge detection of the transformer.
[0084] Further, a plurality of ring-shaped metal rods are arranged inside the main sound focusing structure at a preset interval, and a ring-shaped metal sheet is attached between the upper surface of the magnetic suction base and the lower surface of the main sound focusing structure, which can realize broadband sensitivity enhancement of the optical fiber ultrasonic sensing, thereby widening the detection frequency band of the transformer partial discharge fault type. In addition, the ultrasonic measurement system is placed in the metal shielding box, which can effectively eliminate the interference of other electromagnetic signals in the space on the measurement process, thereby effectively reducing the measurement difficulty and improving the accuracy of the measurement result.
[0085] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described specific embodiments are only for the specific embodiments of the present application and do not limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A partial discharge detection method for a transformer based on acoustic coupling ring structure, characterized in that, The application relates to a transformer partial discharge fault type detection method and device. The first ultrasonic signal transmitted by the transformer is received through the annular metal sheet and the annular metal rods of the acoustic coupling annular structure, and the first ultrasonic signal is subjected to frequency separation processing to obtain second ultrasonic signals corresponding to multiple frequencies, and then each second ultrasonic signal is conducted to the sensing optical fiber of the acoustic coupling annular structure; wherein the second ultrasonic signal corresponds to the frequency one by one; Each second ultrasonic signal and sensing laser emitted by a laser are received through the sensing optical fiber, so that the sensing laser and each second ultrasonic signal are coupled, and backscattering light signals corresponding to each second ultrasonic signal are generated; All the backscattering light signals are conducted to an ultrasonic measurement system, and the local discharge fault type of the transformer is detected in real time; The first ultrasonic signal transmitted by the transformer is received through the annular metal sheet and the annular metal rods of the acoustic coupling annular structure, and the first ultrasonic signal is subjected to frequency separation processing to obtain second ultrasonic signals corresponding to multiple frequencies, and then each second ultrasonic signal is conducted to the sensing optical fiber of the acoustic coupling annular structure; wherein the second ultrasonic signal corresponds to the frequency one by one; The first ultrasonic signal conducted through the magnetic suction base of the acoustic coupling annular structure is received through the annular metal sheet and multiple annular metal rods of the acoustic coupling annular structure; wherein the first ultrasonic signal is transmitted by the transformer to the acoustic coupling annular structure when local discharge occurs in the transformer, the annular metal sheet is pasted between the upper surface of the magnetic suction base and the lower surface of a main acoustic focusing structure, each annular metal rod is embedded in the interior of the main acoustic focusing structure according to a preset interval, the acoustic coupling annular structure is attached to the transformer riser of the transformer, and the magnetic suction base is composed of a magnetic suction base shell and a neodymium magnet embedded in a groove of the magnetic suction base shell; The first ultrasonic signal is subjected to frequency separation processing through the annular metal sheet and the annular metal rods to obtain second ultrasonic signals corresponding to multiple frequencies, and each second ultrasonic signal is conducted to the inner surface of the acoustic coupling annular structure, so as to conduct each second ultrasonic signal to the sensing optical fiber pasted to the inner surface of the acoustic coupling annular structure.
2. The partial discharge detection method of a transformer based on acoustic coupling ring structure according to claim 1, characterized in that, All the backscattering light signals are conducted to an ultrasonic measurement system, and the local discharge fault type of the transformer is detected in real time; The beginning end of the sensing optical fiber is reinforced through an armored optical cable, and all the backscattering light signals are conducted to the ultrasonic measurement system through the reinforced beginning end of the sensing optical fiber; The corresponding local discharge frequency spectrum characteristics are extracted through the ultrasonic measurement system, and the local discharge frequency spectrum characteristics are detected in combination with a feature database, so as to obtain the local discharge fault type of the transformer; The feature database comprises ultrasonic frequency distribution results corresponding to several transformer local discharge fault types.
3. The partial discharge detection method of a transformer based on acoustic coupling ring structure according to claim 2, characterized in that, The application further relates to a transformer partial discharge fault type detection device. The partial discharge spectrum characteristics and the partial discharge fault type are transmitted to a server in real time through a signal transmission system, and the server is controlled to read and display the partial discharge spectrum characteristics and the partial discharge fault type in real time. The ultrasonic measurement system is arranged in a metal shielding box.
4. The partial discharge detection method of a transformer based on acoustic coupling ring structure according to claim 1, characterized in that, Further comprising: A matching terminal is fused at the end of the sensing optical fiber, and sensing laser emitted by the laser is transmitted to the sensing optical fiber through the end of the sensing optical fiber.
5. A partial discharge detection device for a transformer based on acoustic coupling ring structure, characterized in that, Comprising: The signal frequency division module is configured to receive the first ultrasonic signal transmitted by the transformer through the annular metal sheet and the annular metal rods of the acoustic coupling annular structure, and perform frequency separation processing on the first ultrasonic signal to obtain a plurality of second ultrasonic signals corresponding to different frequencies, and then conduct each second ultrasonic signal to the sensing optical fiber of the acoustic coupling annular structure. The coupling module is configured to receive each second ultrasonic signal and sensing laser emitted by the laser through the sensing optical fiber, so that the sensing laser and each second ultrasonic signal are coupled, and backscattering light signals corresponding to each second ultrasonic signal are generated. The detection module is configured to conduct all backscattering light signals to an ultrasonic measurement system, and detect the partial discharge fault type of the transformer in real time. The signal frequency division module specifically comprises: The first signal transmission unit is configured to receive the first ultrasonic signal conducted by the magnetic suction base of the acoustic coupling annular structure through the annular metal sheet and a plurality of annular metal rods of the acoustic coupling annular structure. The signal frequency division unit is configured to perform frequency separation processing on the first ultrasonic signal through the annular metal sheet and the annular metal rods to obtain a plurality of second ultrasonic signals corresponding to different frequencies, and conduct each second ultrasonic signal to the inner surface of the acoustic coupling annular structure, so as to realize the transmission of each second ultrasonic signal to the sensing optical fiber attached to the inner surface of the acoustic coupling annular structure.
6. The partial discharge detection device based on acoustic coupling ring structure transformer of claim 5, wherein, The detection module specifically comprises: The second signal transmission unit is configured to use the armored optical cable to reinforce the beginning end of the sensing optical fiber, and conduct all backscattering light signals after reinforcement to the beginning end of the sensing optical fiber to the ultrasonic measurement system. The detection unit is used for extracting corresponding partial discharge spectrum features through the ultrasonic measurement system, and detecting the partial discharge spectrum features in combination with a feature database to obtain a partial discharge fault type of the transformer; wherein the feature database includes ultrasonic frequency distribution results corresponding to several transformer partial discharge fault types.
7. The partial discharge detection device based on acoustic coupling ring structure transformer of claim 6, wherein, Further comprising: The first transmission module is used for transmitting the partial discharge spectrum features and the partial discharge fault type to a server in real time through a signal transmission system, and controlling the server to read and display the partial discharge spectrum features and the partial discharge fault type in real time; wherein the ultrasonic measurement system is arranged in a metal shielding box.
8. The partial discharge detection device based on acoustic coupling ring structure transformer of claim 5, wherein, Further comprising: The second transmission module is used for welding a matching terminal at the end of the sensing optical fiber, and transmitting sensing laser emitted by a laser to the sensing optical fiber through the end of the sensing optical fiber.
Citation Information
Patent Citations
Partial discharge multi-frequency combined sensing array based on optical fiber Fabry-Perot interferometer
CN113589113A