Spherical sensor integrating ultrasound and ultra high frequency for use in converter transformer, and sensing system

Abstract

The present application relates to a spherical sensor integrating ultrasound and ultra high frequency for use in a converter transformer, and a sensing system. An optical fiber sensing and processing system is connected to a spherical optical fiber ultrasound sensing unit, and an ultra high frequency sensing unit is connected to a data acquisition card; the optical fiber sensing and processing system is connected to a wave filter via the data acquisition card, and the wave filter is connected to a computer; the spherical optical fiber ultrasound sensing unit is in sealed connection with the ultra high frequency sensing unit via a connection rod, and the side of the ultra high frequency sensing unit furthest from the connection rod is in sealed connection with a sensing assembly. The spherical optical fiber ultrasound sensing unit detects ultrasonic signals from all directions inside an oil tank of a converter transformer to be tested.

Description

Spherical ultrasonic UHF integrated sensor and sensing system for converter transformers

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202311126034.0, application date September 1, 2023, and application name “Spherical ultrasonic ultra-high frequency integrated sensor and sensing system for converter transformers”, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into the present disclosure as a reference. Technical Field

[0003] The present application relates to the technical field of power equipment status monitoring, and in particular to a spherical ultrasonic ultra-high frequency integrated sensor and a sensing system for a converter transformer. Background Art

[0004] Currently, high-voltage electrical equipment, such as converter transformers, is a core component of power systems, and its reliable operation is crucial to the stable operation of the power grid. According to a survey report by a working group of the International Council on Large Electric Systems (CIGRE), faults caused by insulation degradation in electrical equipment account for a significant proportion of electrical failures, and insulation failures often lead to more serious safety incidents. Statistics show that the probability of fire or explosion following insulation failure in converter transformers is approximately 10%, posing a serious threat to the safety of power grid operators and maintenance personnel.

[0005] Partial discharge is a key sign and manifestation of insulation failure in electrical equipment. When partial discharge occurs, it is often accompanied by physical characteristics such as pulsed current, electromagnetic waves, ultrasonic waves, optical signals, and gas. By detecting these physical quantities, partial discharge defects within electrical equipment can be promptly detected, providing early warning of faults and ensuring the safety of electrical equipment and the reliability of power supply. However, from a practical application perspective, only ultra-high frequency and ultrasonic methods are relatively practical detection methods.

[0006] Existing transformer partial discharge UHF sensors and ultrasonic sensors are installed independently. Although each sensor has high detection sensitivity and has been widely used in the field, they still have the following technical disadvantages:

[0007] (1) For ultrasonic sensors, the traditional acoustic wave method uses a piezoelectric ceramic transducer, which is installed on the housing of the power equipment to detect the ultrasonic waves generated by partial discharge. This ultrasonic sensor is easy to operate and has mature technology, but the detection sensitivity is low. In contrast, intrinsic fiber interferometry ultrasonic sensing technology has more advantages in weak signal detection and sensitivity. However, while intrinsic fiber interferometry ultrasonic sensing technology has high sensitivity, it is also more susceptible to environmental interference.

[0008] (2) For UHF sensors, high-voltage electrical equipment such as transformers will generate UHF signals between 300 and 3000 MHz during partial discharge. Although UHF methods can be used to detect partial discharge signals online, the UHF signal attenuates quickly during the detection process and has weak anti-interference capabilities.

[0009] Summary of the Invention

[0010] In response to the shortcomings of the existing technology, the purpose of this application is to provide a spherical ultrasonic ultra-high frequency integrated sensor and sensing system for converter transformers. Its advantages are that it can solve the technical problems of low sensitivity, easy omission and false alarm of existing single-type sensors, improve the accuracy of transformer partial discharge sensing measurement, and solve the problem of implanting optical fiber sensors in the transformer partial discharge measurement process.

[0011] The above-mentioned purpose of the present application is achieved through the following technical solutions: The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, comprising a spherical optical fiber ultrasonic sensor unit, an ultra-high frequency sensor unit and a sensor assembly; the spherical optical fiber ultrasonic sensor unit is sealedly connected to the ultra-high frequency sensor unit through a connecting rod, and the side of the ultra-high frequency sensor unit away from the connecting rod is sealedly connected to the sensor assembly, and the spherical optical fiber ultrasonic sensor unit is configured to extend into the oil tank of the converter transformer to be tested through the oil intake port of the converter transformer to be tested, so as to simultaneously collect ultra-high frequency signals and ultrasonic signals to monitor the operating status of the converter transformer to be tested.

[0012] The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, wherein the spherical optical fiber ultrasonic sensing unit is formed into a hollow sphere by uniformly winding an optical fiber of a preset length.

[0013] The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, wherein the sensor assembly includes a mounting unit, a flange, a signal output interface unit, a first signal transmission unit, and a second signal transmission unit. One side of the mounting unit is sealed and connected to a side of the ultra-high frequency sensing unit away from the connecting rod, and the other side of the mounting unit is connected to one side of the flange, and the side of the flange away from the mounting unit is connected to the signal output interface unit; one end of the first signal transmission unit is connected to the spherical fiber optic ultrasonic sensing unit, and the other end of the first signal transmission unit is connected to the signal output interface unit, one end of the second signal transmission unit is connected to the ultra-high frequency sensing unit, and the other end of the second signal transmission unit is connected to the signal output interface unit.

[0014] The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, wherein the mounting unit includes an insulating disk and a mounting disk, one side of the mounting disk is sealedly connected to the insulating disk, the other side of the mounting disk is connected to the side of the flange away from the signal output interface unit, and the side of the insulating disk away from the mounting disk is sealedly connected to the side of the ultra-high frequency sensing unit away from the connecting rod.

[0015] The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, wherein the sensor assembly further comprises a protective cover, wherein the protective cover is connected to the side of the flange away from the mounting unit, and the protective cover and the flange together constitute a receiving cavity, wherein the signal output interface unit is accommodated in the receiving cavity and connected to the flange.

[0016] The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, wherein the signal output interface unit includes an N-type connector, an optical fiber connector, and an optical fiber passivator. The N-type connector and the optical fiber connector are both sealed with sealant to the side of the flange away from the mounting unit, the N-type connector and the optical fiber connector are spaced apart, and the N-type connector is connected to one end of the second signal transmission unit away from the ultra-high frequency sensing unit; the optical fiber passivator is sealed with sealant to the side of the flange away from the mounting unit, one side of the optical fiber passivator is connected to the optical fiber connector, and the other side of the optical fiber passivator is connected to one end of the first signal transmission unit away from the spherical optical fiber ultrasonic sensing unit.

[0017] The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, wherein the first signal transmission unit includes an optical fiber jumper and an FC optical fiber connector, one end of the optical fiber jumper is connected to the spherical optical fiber ultrasonic sensing unit, the other end of the optical fiber jumper is connected to the FC optical fiber connector, and the end of the FC optical fiber connector facing away from the optical fiber jumper is connected to the side of the optical fiber passivator facing away from the optical fiber connector.

[0018] The present application provides a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, wherein the second signal transmission unit includes a coaxial cable and an SMA signal connector, one end of the coaxial cable is connected to the ultra-high frequency sensing unit, the other end of the coaxial cable is connected to the SMA signal connector, and the end of the SMA signal connector facing away from the coaxial cable is connected to the N-type connector.

[0019] The spherical ultrasonic ultra-high frequency integrated sensor for the converter transformer provided in the present application has a preset inner diameter of the hollow sphere ranging from 5 mm to 15 mm, and a preset outer diameter of the hollow sphere ranging from 20 mm to 40 mm.

[0020] The spherical ultrasonic ultra-high frequency integrated sensor for the converter transformer provided in the present application has a preset length ranging from 80m to 120m.

[0021] The present application provides a sensing system, comprising a fiber optic sensing processing system, a data acquisition card, a filter, a computer, and the above-mentioned spherical ultrasonic ultra-high frequency integrated sensor. The fiber optic sensing processing system is connected to the spherical fiber optic ultrasonic sensing unit in the spherical ultrasonic ultra-high frequency integrated sensor, the ultra-high frequency sensing unit in the spherical ultrasonic ultra-high frequency integrated sensor is connected to the data acquisition card, the fiber optic sensing processing system is connected to the filter via the data acquisition card, and the filter is connected to the computer. The fiber optic sensing processing system is used to collect ultrasonic signals, filter the ultrasonic signals, and perform analysis and calculations on the ultrasonic signals.

[0022] The sensing system provided in the present application comprises a fiber optic sensing processing system including a laser, an optical isolator, a Faraday rotating reflector, a photodetector, a power splitter and a detector. The laser is connected to the optical isolator, and the optical isolator is connected to the photodetector via a first coupler, an acousto-optic modulation unit and a second coupler. The acousto-optic modulation unit comprises a circulator and an acousto-optic modulation module. The circulator is connected to the acousto-optic modulation module. The circulator is connected to the Faraday rotating reflector via the spherical fiber optic ultrasonic sensing unit. The acousto-optic modulation module is connected to the power splitter. The power splitter and the photodetector are both connected to the detector. The detector is connected to the filter via the data acquisition card.

[0023] In the sensing system provided in the present application, the acousto-optic modulation module includes a reference optical fiber and an acousto-optic modulator, and the acousto-optic modulator is connected to the reference optical fiber.

[0024] In summary, the beneficial technical effects of the present application are as follows: the present application provides a spherical ultrasonic UHF integrated sensor and sensing system for a converter transformer, the sensing system includes an optical fiber sensing processing system, a data acquisition card, a filter, a computer and a spherical ultrasonic UHF integrated sensor, the optical fiber sensing processing system is connected to the spherical optical fiber ultrasonic sensing unit in the spherical ultrasonic UHF integrated sensor, the UHF sensing unit in the spherical ultrasonic UHF integrated sensor is connected to the data acquisition card, the optical fiber sensing processing system is connected to the filter through the data acquisition card, and the filter is connected to the computer; the optical fiber sensing processing system is used to collect ultrasonic signals, filter the ultrasonic signals, and analyze and calculate them; the spherical ultrasonic UHF integrated sensor includes a spherical optical fiber ultrasonic sensing unit, an UHF sensing unit and a sensing component; the spherical optical fiber ultrasonic sensing unit The sensing unit is sealed and connected to the ultra-high frequency sensing unit through a connecting rod, and the ultra-high frequency sensing unit is sealed and connected to the sensing assembly on a side away from the connecting rod. The spherical optical fiber ultrasonic sensing unit is configured to extend into the oil tank of the converter transformer to be tested through the oil inlet of the converter transformer to be tested, so as to simultaneously collect ultra-high frequency signals and ultrasonic signals and monitor the operating status of the converter transformer to be tested. By setting the spherical optical fiber ultrasonic sensing unit to be sealed and connected to the ultra-high frequency sensing unit through the connecting rod, the spherical optical fiber ultrasonic sensing unit detects ultrasonic signals in all directions inside the oil tank of the converter transformer to be tested, thereby realizing omnidirectional detection of partial discharge signals in the oil. At the same time, the ultra-high frequency sensing unit detects the ultra-high frequency signal generated by the partial discharge of the converter transformer to be tested. Through the joint detection of the acoustic and electrical signals of the partial discharge, the accuracy of the partial discharge sensing measurement of the converter transformer to be tested is improved.

[0025] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and, together with the specification, are used to illustrate the technical solutions of the present application.

[0027] FIG1 is a schematic diagram of the overall structure of a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer provided in an embodiment of the present application.

[0028] FIG2 is a schematic diagram of the working structure of a spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer provided in an embodiment of the present application.

[0029] FIG3 is a structural block diagram of a sensing system provided in another embodiment of the present application.

[0030] In the figure, 1. Spherical ultrasonic UHF integrated sensor; 10. Spherical fiber optic ultrasonic sensor unit; 20. UHF sensor unit; 30. Sensor assembly; 31. Mounting unit; 311. Insulation disk; 312. Mounting disk; 32. Flange; 33. Fiber optic connector; 34. Protective cover; 341. Accommodation cavity; 40. Connecting rod; 2. Sensing system; 21. Fiber optic sensor processing system; 211. Laser; 212. Optical isolator; 21 3. Faraday rotator mirror; 214. Photodetector; 215. Power divider; 216. Detector; 217. First coupler; 218. Acousto-optic modulation unit; 2181. Circulator; 2182. Acousto-optic modulation module; 2183. Reference optical fiber; 2184. Acousto-optic modulator; 219. Second coupler; 220. Driver; 22. Data acquisition card; 23. Filter; 24. Computer; 3. Converter transformer to be tested. DETAILED DESCRIPTION

[0031] The present application is further described in detail below with reference to the accompanying drawings.

[0032] 1 and 2, a spherical ultrasonic UHF integrated sensor 1 for a converter transformer provided in an embodiment of the present application includes a spherical optical fiber ultrasonic sensor unit 10, an UHF sensor unit 20 and a sensor assembly 30; the spherical optical fiber ultrasonic sensor unit 10 is sealedly connected to the UHF sensor unit 20 through a connecting rod 40, and the UHF sensor unit 20 is sealedly connected to the sensor assembly 30 on the side away from the connecting rod 40, and the spherical optical fiber ultrasonic sensor unit 10 is inserted into the oil tank of the converter transformer 3 to be tested through the oil inlet of the converter transformer 3 to simultaneously collect UHF signals and ultrasonic signals to monitor the operating status of the converter transformer 3 to be tested; on the one hand, by setting the spherical optical fiber ultrasonic sensor unit 10 to be sealedly connected to the UHF sensor unit 20 through the connecting rod 40, the spherical optical fiber ultrasonic sensor unit 10 is sealedly connected to the UHF sensor unit 20 The spherical optical fiber ultrasonic sensing unit 10 detects ultrasonic signals in all directions inside the oil tank of the converter transformer 3 to be tested, thereby realizing omnidirectional detection of partial discharge signals in the oil. At the same time, the ultra-high frequency sensing unit 20 detects the electromagnetic wave signal (i.e., the ultra-high frequency signal) generated by the partial discharge of the converter transformer 3 to be tested. By jointly detecting the acoustic signal and the electrical signal in the partial discharge process, the accuracy of the partial discharge sensing measurement of the converter transformer 3 to be tested is improved. On the other hand, by setting the spherical optical fiber ultrasonic sensing unit 10 to extend into the oil tank of the converter transformer 3 to be tested, it is convenient to implant it into the converter transformer 3 to be tested. At the same time, the spherical optical fiber ultrasonic sensing unit 10 has good resistance to environmental disturbances and corrosion by converter transformer oil, has good insulation performance, and has long-term working stability.

[0033] In some embodiments, based on the acoustic and electrical physical phenomena generated by the partial discharge of the converter transformer 3 to be tested, during use, the spherical fiber optic ultrasonic sensor unit 10 is extended into the oil tank of the converter transformer 3 to be tested through the oil intake port of the converter transformer 3 to be tested, so as to realize the simultaneous collection of ultra-high frequency signals and ultrasonic signals, thereby further improving the accuracy of monitoring the operating status of the converter transformer 3 to be tested.

[0034] It should be noted that the UHF sensing unit 20 is an antenna vibrator. The frequency response curve of the UHF sensing unit 20 has an attenuation or gain of no more than 3dB in the frequency band from 300MHz to 1.5GHz. The signal gain is maximum when detecting the high-frequency partial discharge signal of the converter transformer, which facilitates signal acquisition. The UHF sensing unit 20 directly couples the partial discharge ultrasonic signal in the oil, thereby reducing the degree of attenuation of the acoustic signal.

[0035] In some embodiments, the spherical fiber optic ultrasonic sensor unit 10 is formed into a hollow sphere by uniformly winding an optical fiber of a preset length.

[0036] Among them, the preset inner diameter of the hollow ball ranges from 5mm to 15mm, the preset outer diameter of the hollow ball ranges from 20mm to 40mm, and the preset length ranges from 80m to 120m. In some embodiments, the preset inner diameter of the hollow ball is 10mm, the preset outer diameter is 30mm, and the preset length is 100m.

[0037] In some embodiments, the spherical fiber optic ultrasonic sensor unit 10 is a hollow sphere with an outer diameter of 30 mm formed by evenly winding 100 m of optical fiber.

[0038] In some embodiments, the spherical fiber optic ultrasonic sensor unit 10 uses a G.657 single-mode optical fiber; of course, the spherical fiber optic ultrasonic sensor unit 10 can also use other types of optical fibers.

[0039] In some embodiments, the sensing assembly 30 includes a mounting unit 31, a flange 32, a signal output interface unit, a first signal transmission unit, and a second signal transmission unit. One side of the mounting unit 31 is sealed and connected to the side of the ultra-high frequency sensing unit 20 away from the connecting rod 40, the other side of the mounting unit 31 is connected to one side of the flange 32, and the side of the flange 32 away from the mounting unit 31 is connected to the signal output interface unit; one end of the first signal transmission unit is connected to the spherical fiber optic ultrasonic sensing unit 10, the other end of the first signal transmission unit is connected to the signal output interface unit, one end of the second signal transmission unit is connected to the ultra-high frequency sensing unit 20, and the other end of the second signal transmission unit is connected to the signal output interface unit.

[0040] Taking the orientation shown in FIG. 1 as an example, the right side of the flange 32 is connected to the mounting unit 31 , and the left side of the flange 32 is connected to the signal output interface unit.

[0041] In some embodiments, the central axis of the flange 32 is arranged parallel to the central axis of the connecting rod 40. In some feasible embodiments, the central axis of the flange 32 is arranged collinearly with the central axis of the connecting rod 40.

[0042] For example, the flange 32 is a DN150 flange 32 ; of course, the flange 32 may also be a flange 32 of other types.

[0043] Continuing with reference to Figure 1, in some embodiments, the mounting unit 31 includes an insulating disk 311 and a mounting disk 312, one side of the mounting disk 312 is sealedly connected to the insulating disk 311, the other side of the mounting disk 312 is connected to the side of the flange 32 facing away from the signal output interface unit, and the side of the insulating disk 311 facing away from the mounting disk 312 is sealedly connected to the side of the UHF sensing unit 20 facing away from the connecting rod 40.

[0044] Taking the orientation shown in Figure 1 as an example, the right side of the insulating disk 311 is sealed connected to the UHF sensing unit 20, the left side of the insulating disk 311 is sealed connected to the right side of the mounting disk 312, and the left side of the mounting disk 312 is connected to the flange 32.

[0045] In some embodiments, the central axis of the insulating disk 311 is arranged parallel to the central axis of the mounting disk 312 . In some achievable embodiments, the central axis of the insulating disk 311 is arranged collinearly with the central axis of the mounting disk 312 .

[0046] The central axis of the insulating disk 311 is arranged parallel to the central axis of the connecting rod 40 . In some practicable embodiments, the central axis of the insulating disk 311 is arranged collinearly with the central axis of the connecting rod 40 .

[0047] During use, the spherical optical fiber ultrasonic sensor unit 10 extends into the oil tank of the converter transformer 3 to be tested, and the mounting plate 312 is connected to the converter transformer 3 to be tested.

[0048] In some embodiments, the sensor assembly 30 also includes a protective cover 34, which is connected to the side of the flange 32 facing away from the mounting unit 31. The protective cover 34 and the flange 32 together constitute a accommodating cavity 341, and the signal output interface unit is accommodated in the accommodating cavity 341 and connected to the flange 32.

[0049] Taking the orientation shown in FIG. 1 as an example, the left side of the flange 32 is connected to the protective cover 34 , and the right side of the flange 32 is connected to the mounting plate 312 .

[0050] In some embodiments, the signal output interface unit includes an N-type connector, an optical fiber connector 33, and an optical fiber through-hole. The N-type connector and the optical fiber connector 33 are both sealed with sealant to the side of the flange 32 away from the mounting unit 31. The N-type connector and the optical fiber connector 33 are spaced apart, and the N-type connector is connected to one end of the second signal transmission unit away from the ultra-high frequency sensing unit 20; the optical fiber through-hole is sealed with sealant to the side of the flange 32 away from the mounting unit 31, one side of the optical fiber through-hole is connected to the optical fiber connector 33, and the other side of the optical fiber through-hole is connected to one end of the first signal transmission unit away from the spherical optical fiber ultrasonic sensing unit 10.

[0051] The optical fiber threader adopts a standard 1 / 4-18 NPT (National (American) Pipe Thread, NPT).

[0052] In some embodiments, the first signal transmission unit includes a fiber optic jumper and a FC fiber optic connector (FC), one end of the fiber optic jumper is connected to the spherical fiber optic ultrasonic sensing unit 10, the other end of the fiber optic jumper is connected to the FC fiber optic connector, and the end of the FC fiber optic connector facing away from the fiber optic jumper is connected to the side of the fiber optic vial facing away from the fiber optic connector 33.

[0053] In some embodiments, the second signal transmission unit includes a coaxial cable and an SMA (Sub-Miniature-A, SMA) signal connector, one end of the coaxial cable is connected to the UHF sensing unit 20, the other end of the coaxial cable is connected to the SMA signal connector, and the end of the SMA signal connector facing away from the coaxial cable is connected to the N-type connector.

[0054] Exemplarily, the coaxial cable is a 50Ω impedance coaxial cable.

[0055] Continuing with reference to Figure 3, an embodiment of the present application provides a sensing system 2, including a fiber optic sensing processing system 21, a data acquisition card 22, a filter 23, a computer 24 and the above-mentioned spherical ultrasonic UHF integrated sensor 1. The fiber optic sensing processing system 21 is connected to the spherical fiber optic ultrasonic sensing unit 10 in the spherical ultrasonic UHF integrated sensor 1, the UHF sensing unit 20 in the spherical ultrasonic UHF integrated sensor 1 is connected to the data acquisition card 22, the fiber optic sensing processing system 21 is connected to the filter 23 through the data acquisition card 22, and the filter 23 is connected to the computer 24; the fiber optic sensing processing system 21 is used to collect ultrasonic signals and filter, analyze and calculate the ultrasonic signals.

[0056] In some embodiments, the spherical fiber optic ultrasonic sensor unit 10 is connected to the fiber optic sensing processing system 21 via an FC fiber optic connector, and the ultra-high frequency sensor unit 20 is connected to the data acquisition card 22 via an SMA signal connector.

[0057] The optical fiber sensing and processing system 21 adopts a Michelson optical fiber sensing and processing system 21 ; and the data acquisition card 22 adopts an NI acquisition card.

[0058] During use, the optical fiber sensing and processing system 21 monitors ultrasonic signals from all directions inside the oil tank of the converter transformer 3 under test, the spherical optical fiber ultrasonic sensing unit 10 detects ultrasonic signals from all directions inside the oil tank of the converter transformer 3 under test, the UHF sensing unit 20 detects UHF signals generated by partial discharge of the converter transformer 3 under test, the data acquisition card 22 collects UHF signals, the optical fiber sensing and processing system 21 collects ultrasonic signals, the optical fiber sensing and processing system 21 transmits the ultrasonic signals to the data acquisition card 22, the data acquisition card 22 simultaneously transmits the ultrasonic signals and the UHF signals to the filter 23, the filter 23 processes the ultrasonic signals and the UHF signals and transmits the processed ultrasonic signals and the UHF signals to the computer 24.

[0059] In some embodiments, the fiber optic sensing processing system 21 includes a laser 211, an optical isolator 212, a Faraday rotator mirror 213, a balanced photodiode 214 (BPD), a power splitter 215, and a detector 216. The laser 211 is connected to the optical isolator 212, and the optical isolator 212 is connected to the photodetector 214 (BPD) through a first coupler 217, an acousto-optic modulation unit 218, and a second coupler 219. The acousto-optic modulation unit 218 includes a circulator 2181 and an acousto-optic modulation module 2182. The circulator 2181 is connected to the acousto-optic modulation module 2182. The circulator 2181 is connected to the Faraday rotator mirror 213 through the spherical fiber optic ultrasonic sensing unit 10. The acousto-optic modulation module 2182 is connected to the power splitter 215. The power splitter 215 and the photodetector 214 are both connected to the detector 216. The detector 216 is connected to the filter 23 through the data acquisition card 22.

[0060] The laser 211 is a 1550 nm ultra-narrow linewidth laser 211 , the first coupler 217 is a 1×2 fiber coupler, the second coupler 219 is a 2×2 fiber coupler, and the detector 216 is an RF gain phase detector 216 (Radio Frequency, RF).

[0061] The optical fiber sensing processing system 21 further includes a driver 220 , a first end of the power splitter 215 is connected to the acousto-optic modulation module 2182 , a second end of the power splitter 215 is connected to the detector 216 , and a third end of the power splitter 215 is connected to the driver 220 .

[0062] In this embodiment, the working principle of the optical fiber sensing processing system 21 is as follows: the acousto-optic modulation module 2182 converts the received optical signal into an electrical signal output, the computer 24 filters the electrical signal, and presents the processing result on the display screen of the computer 24.

[0063] In some embodiments, the AOM module 2182 includes a reference optical fiber 2183 and an AOM 2184 . The AOM 2184 is connected to the reference optical fiber 2183 .

[0064] In some embodiments, a first end of the power divider 215 is connected to the acousto-optic modulator 2184 (AOM), a second end of the power divider 215 is connected to the detector 216 , and a third end of the power divider 215 is connected to the driver 220 .

[0065] The working principle of the sensing system 2 provided by the present disclosure is as follows: the spherical fiber optic ultrasonic sensing unit 10 is extended into the oil tank of the converter transformer 3 to be tested, the spherical fiber optic ultrasonic sensing unit 10 detects ultrasonic signals in all directions inside the oil tank of the converter transformer 3 to be tested, the ultra-high frequency sensing unit 20 detects the ultra-high frequency signal generated by the partial discharge of the converter transformer 3 to be tested, the data acquisition card 22 collects the ultra-high frequency signal, the photoelectric detector 214 (BPD) transmits the received ultrasonic signal to the data acquisition card 22 through the detector 216, the data acquisition card 22 simultaneously transmits the ultrasonic signal and the ultra-high frequency signal to the filter 23, the filter 23 processes the received ultrasonic signal and the ultra-high frequency signal, and transmits the processed signal to the computer 24.

[0066] The sensing system 2 provided by the present disclosure includes an optical fiber sensing processing system 21, a data acquisition card 22, a filter 23, a computer 24 and a spherical ultrasonic ultra-high frequency integrated sensor 1. The optical fiber sensing processing system 21 is connected to the spherical optical fiber ultrasonic sensing unit 10 in the spherical ultrasonic ultra-high frequency integrated sensor 1, and the ultra-high frequency sensing unit 20 in the spherical ultrasonic ultra-high frequency integrated sensor 1 is connected to the data acquisition card 22. The optical fiber sensing processing system 21 is connected to the filter 23 through the data acquisition card 22, and the filter 23 is connected to the computer 24; the optical fiber sensing processing system 21 is used to collect ultrasonic signals and filter, analyze and calculate the ultrasonic signals; the spherical ultrasonic ultra-high frequency integrated sensor 1 includes a spherical optical fiber ultrasonic sensing unit 10, an ultra-high frequency sensing unit 20 and a sensing assembly 30; the spherical optical fiber ultrasonic sensing unit 10 is connected to the ultra-high frequency sensing unit 20 through a connecting rod 40 The sensing unit 20 is sealed and connected, and the side of the UHF sensing unit 20 away from the connecting rod 40 is sealed and connected to the sensing assembly 30. The spherical optical fiber ultrasonic sensing unit 10 extends into the oil tank of the converter transformer 3 to be tested through the oil inlet of the converter transformer 3 to be tested, so as to simultaneously collect the UHF signal and the ultrasonic signal to monitor the operating status of the converter transformer 3 to be tested. By setting the spherical optical fiber ultrasonic sensing unit 10 to be sealed and connected to the UHF sensing unit 20 through the connecting rod 40, the spherical optical fiber ultrasonic sensing unit 10 detects the ultrasonic signals in all directions inside the oil tank of the converter transformer 3 to be tested, thereby realizing omnidirectional detection of partial discharge signals in the oil. At the same time, the UHF sensing unit 20 detects the UHF signal generated by the partial discharge of the converter transformer 3 to be tested. By jointly detecting the acoustic signal and the electrical signal of the partial discharge, the accuracy of the partial discharge sensing measurement of the converter transformer 3 to be tested is improved.

[0067] The spherical ultrasonic ultra-high frequency integrated sensor 1 for a converter transformer provided by the present disclosure has the following advantages: the device has a simple structure, is easy to manufacture, and is convenient to implant.

[0068] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0069] Finally, it should be noted that the above embodiments are merely examples for the purpose of illustrating the present application and are not intended to limit the embodiments. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all embodiments here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.

Claims

1. A spherical ultrasonic ultra-high frequency integrated sensor for a converter transformer, comprising: Spherical fiber optic ultrasonic sensor unit, ultra-high frequency sensor unit and sensor assembly; The spherical fiber optic ultrasonic sensor unit is sealed and connected to the UHF sensor unit via a connecting rod, and the UHF sensor unit is sealed and connected to the sensor assembly at a side away from the connecting rod. The spherical fiber optic ultrasonic sensor unit extends into the oil tank of the converter transformer to be tested through the oil inlet of the converter transformer to be tested, so as to simultaneously collect UHF signals and ultrasonic signals and monitor the operating status of the converter transformer to be tested.

2. The spherical ultrasonic ultra-high frequency integrated sensor for converter transformer according to claim 1, wherein: The spherical optical fiber ultrasonic sensor unit is formed into a hollow sphere by evenly winding an optical fiber of a preset length.

3. The spherical ultrasonic UHF integrated sensor for converter transformer according to claim 1, wherein: The sensor assembly includes a mounting unit, a flange, a signal output interface unit, a first signal transmission unit, and a second signal transmission unit, one side of the mounting unit is sealed and connected to a side of the UHF sensor unit away from the connecting rod, the other side of the mounting unit is connected to a side of the flange, and a side of the flange away from the mounting unit is connected to the signal output interface unit; One end of the first signal transmission unit is connected to the spherical fiber optic ultrasonic sensor unit, and the other end of the first signal transmission unit is connected to the signal output interface unit. One end of the second signal transmission unit is connected to the ultra-high frequency sensor unit, and the other end of the second signal transmission unit is connected to the signal output interface unit.

4. The spherical ultrasonic UHF integrated sensor for converter transformer according to claim 3, wherein: The mounting unit includes an insulating disk and a mounting disk, one side of the mounting disk is sealedly connected to the insulating disk, the other side of the mounting disk is connected to a side of the flange away from the signal output interface unit, and the side of the insulating disk away from the mounting disk is sealedly connected to a side of the UHF sensing unit away from the connecting rod.

5. The spherical ultrasonic UHF integrated sensor for converter transformer according to claim 3, wherein: The sensor assembly also includes a protective cover, which is connected to the side of the flange away from the mounting unit. The protective cover and the flange together form a receiving cavity. The signal output interface unit is accommodated in the receiving cavity and connected to the flange.

6. The spherical ultrasonic UHF integrated sensor for converter transformer according to claim 5, wherein: The signal output interface unit comprises an N-type connector, an optical fiber connector and an optical fiber through-hole, the N-type connector and the optical fiber connector are both sealed to the side of the flange away from the mounting unit by sealant, the N-type connector and the optical fiber connector are arranged at intervals, and the N-type connector is connected to the end of the second signal transmission unit away from the UHF sensing unit; The fiber optic penetrator is sealed to the side of the flange away from the mounting unit by sealant, one side of the fiber optic penetrator is connected to the fiber optic connector, and the other side of the fiber optic penetrator is connected to the end of the first signal transmission unit away from the spherical fiber optic ultrasonic sensor unit.

7. The spherical ultrasonic UHF integrated sensor for converter transformer according to claim 6, wherein: The first signal transmission unit includes an optical fiber jumper and an FC optical fiber connector, one end of the optical fiber jumper is connected to the spherical optical fiber ultrasonic sensor unit, the other end of the optical fiber jumper is connected to the FC optical fiber connector, and one end of the FC optical fiber connector facing away from the optical fiber jumper is connected to a side of the optical fiber through-hole facing away from the optical fiber connector.

8. The spherical ultrasonic ultra-high frequency integrated sensor for converter transformer according to any one of claims 6 to 7, wherein: The second signal transmission unit includes a coaxial cable and an SMA signal connector, one end of the coaxial cable is connected to the UHF sensing unit, the other end of the coaxial cable is connected to the SMA signal connector, and the end of the SMA signal connector facing away from the coaxial cable is connected to the N-type connector.

9. The spherical ultrasonic UHF integrated sensor for converter transformer according to claim 2, wherein: The preset inner diameter of the hollow ball ranges from 5 mm to 15 mm, and the preset outer diameter of the hollow ball ranges from 20 mm to 40 mm.

10. The spherical ultrasonic ultra-high frequency integrated sensor for converter transformer according to claim 2, wherein: The preset length ranges from 80m to 120m.

11. A sensing system comprising: An optical fiber sensing processing system, a data acquisition card, a filter, a computer, and the spherical ultrasonic UHF integrated sensor according to any one of claims 1 to 10, wherein the optical fiber sensing processing system is connected to the spherical optical fiber ultrasonic sensing unit in the spherical ultrasonic UHF integrated sensor, the UHF sensing unit in the spherical ultrasonic UHF integrated sensor is connected to the data acquisition card, the optical fiber sensing processing system is connected to the filter through the data acquisition card, and the filter is connected to the computer; The optical fiber sensing processing system is used to collect ultrasonic signals and filter, analyze and calculate the ultrasonic signals.

12. The sensing system of claim 11, wherein: The optical fiber sensing processing system comprises a laser, an optical isolator, a Faraday rotating reflector, a photodetector, a power divider and a detector, wherein the laser is connected to the optical isolator, and the optical isolator is connected to the photodetector via a first coupler, an acousto-optic modulation unit and a second coupler; The acousto-optic modulation unit includes a circulator and an acousto-optic modulation module, the circulator is connected to the acousto-optic modulation module, the circulator is connected to the Faraday rotating reflector through the spherical optical fiber ultrasonic sensor unit, the acousto-optic modulation module is connected to the power divider, and the power divider and the photoelectric detector are both connected to the detector; The detector is connected to the filter through the data acquisition card.

13. The sensing system of claim 12, wherein: The acousto-optic modulation module includes a reference optical fiber and an acousto-optic modulator, and the acousto-optic modulator is connected to the reference optical fiber.

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