Built-in ultrasonic and ultrahigh frequency partial discharge array monitoring device for transformer

Abstract

The invention discloses a built-in ultrasonic and ultrahigh-frequency partial discharge array monitoring device for a transformer, which comprises 17 groups of sensors, an optical fiber communication system, a signal processing circuit and a signal analysis system, and is characterized in that each group comprises an ultrasonic partial discharge sensor and an ultrahigh-frequency partial discharge sensor; each group of sensors is mounted in the transformer through the mounting base, and the sensors convert analog signals into optical signals through the optical fiber communication system, transmit the optical signals to the signal processing circuit, decode the optical signals, convert the optical signals into digital signals, and transmit the digital signals to the signal processing circuit. The processing result of the signal processing circuit is processed by the signal analysis system to obtain the partial discharge position and assignment in the transformer, and data support is provided for operation and inspection personnel to judge the type and severity of internal faults; the monitoring device monitors partial discharge signals in the transformer, realizes real-time monitoring, effectively avoids interference of external noise on the sensor, improves the response speed of the monitoring device, and ensures safe operation of the transformer.

Description

Technical Field

[0001] The invention relates to the technical field of transformer fault monitoring, and in particular to a transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device. Background Art

[0002] During the production and operation of transformers, if the winding process and the core clamp stacking process are poor, it is easy to cause internal partial discharge, resulting in insulation degradation and serious failure of the transformer. The current means of partial discharge monitoring for transformers are mainly external ultrasonic partial discharge monitoring technology, core clamp high-frequency partial discharge monitoring technology and online monitoring technology of dissolved gas in oil.

[0003] Due to the complex internal structure of the transformer, the ultrasonic signal generated by the internal partial discharge is submerged in the external noise signal after attenuation in the propagation path, making it extremely difficult to detect. The disadvantage of the high-frequency partial discharge monitoring technology for core clamps is that its signal is easily affected by the corona signal in the external space, making it difficult to distinguish between the real partial discharge signal and the interference signal. The disadvantage of the online monitoring technology for dissolved gas in oil is that its response time is long, usually requiring 20 to 30 minutes to complete the detection, and the early warning of sudden faults is poor. Therefore, a monitoring technology is needed to respond to faults quickly and accurately to protect the transformer.

[0004] In the prior art, a number of solutions have been proposed for partial discharge monitoring of oil-filled equipment. They mainly include three categories: 1. Ultrasonic partial discharge monitoring technology. Transformer external ultrasonic partial discharge technology mainly uses ultrasonic sensors to detect partial discharge phenomena inside the transformer. When partial discharge occurs inside the transformer, ultrasonic signals will be generated. These signals can be transmitted to the outside through the wall of the transformer oil tank and captured by the ultrasonic sensor. The sensor is usually installed on the metal box wall of the transformer to receive the ultrasonic signals generated by the internal discharge of the transformer. 2. Core clamp high-frequency partial discharge technology. The high-frequency sensor installed on the core clamp is used to monitor the internal partial discharge phenomenon of the transformer in the grounding current of the core addition. The sensor uses a high-precision current sensor. 3. Online oil chromatography technology. Online oil chromatography technology indirectly judges the fault situation inside the transformer by monitoring the gas composition and content dissolved in the transformer oil. Using the principle of gas chromatography analysis, the degassing technology combining vacuum and ultrasonic electromagnetic oscillation is adopted, and the composite chromatographic column gas separation method is applied to realize the online detection of multi-component gases dissolved in transformer oil.

[0005] The main disadvantages of the above technical solutions are:

[0006] Ultrasonic partial discharge monitoring technology: Ultrasonic sensors are easily interfered by environmental noise, such as mechanical vibration, wind noise, and human noise, which may affect the accurate detection of partial discharge signals. Although ultrasonic sensors can detect ultrasonic signals generated by discharge, it may be difficult to locate the specific location of the discharge source in large transformers because ultrasonic signals may be reflected and attenuated by the tank wall and other structures during propagation. For weak discharge signals, the sensitivity of ultrasonic sensors may not be enough to capture these signals, resulting in missed detection.

[0007] High-frequency partial discharge technology for core clamps: High-frequency sensors may be affected by electromagnetic interference, such as the operation of other electrical equipment, lightning activity, etc., which may affect the accurate detection of partial discharge signals. This technology mainly monitors the discharge phenomenon in the grounding current of the core clamps, and cannot effectively monitor the discharge in other parts.

[0008] Online oil chromatography technology: Although it is online monitoring, gas chromatography analysis takes a certain amount of time to complete, so it cannot provide real-time discharge information. This technology indirectly determines the fault situation inside the transformer by monitoring the gas composition and content dissolved in the transformer oil, so it may not directly provide the specific location or type of discharge. Summary of the invention

[0009] In order to overcome the above problems, the purpose of the present invention is to provide a transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device. The monitoring device is composed of multiple groups of ultrasonic and ultra-high frequency sensors arranged on the inner box wall of the transformer to form an array, so as to monitor the partial discharge signals of the internal windings, core clamps, risers and other parts of the transformer, realize real-time monitoring of the internal state of the equipment, effectively avoid the interference of external noise on the sensor, improve the response speed of the monitoring device, and ensure the safe operation of the transformer.

[0010] The technical solution adopted by the present invention is:

[0011] A transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device, including a sensor, an optical fiber communication system, a signal processing circuit, and a signal analysis system.

[0012] There are 17 groups of sensors, each group includes an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor. Each group of sensors is installed inside the transformer through a mounting base to detect partial discharge signals inside the transformer. The sensor converts analog signals into optical signals through an optical fiber communication system and transmits them to a signal processing circuit, which decodes the optical signals and converts them into digital signals. The processing results of the signal processing circuit are processed by a signal analysis system to obtain the location and value of partial discharge inside the transformer, providing data support for operation and inspection personnel to determine the type and severity of internal faults.

[0013] The 17 groups of sensors are installed inside the transformer in an array.

[0014] The first, second, third, fourth and fifth groups of sensors are arranged on one side of the transformer bushing elevation seat, the first and second groups of sensors are located on the left side of the elevation seat, the third group of sensors are arranged on the elevation seat, and the fourth and fifth groups of sensors are located on the right side of the elevation seat;

[0015] The sixth, seventh and eighth groups of sensors are arranged on one side of the transformer tap switch, and the seventh group of sensors is located directly above the eighth group of sensors;

[0016] The ninth and tenth groups of sensors are arranged on one side of the non-tap switch of the transformer, and the ninth group of sensors is located directly above the tenth group of sensors;

[0017] The eleventh, twelfth, thirteenth and fourteenth groups of sensors are arranged at the radiator position of the transformer;

[0018] The fifteenth group of sensors, the sixteenth group of sensors and the seventeenth group of sensors are arranged on the top of the transformer.

[0019] As a further description of the present invention, the first group of sensors is arranged at a position 1 / 2 of the top of the transformer in the longitudinal direction and 1 / 4 of the lateral size of the transformer from the tap changer in the lateral direction; the second group of sensors is arranged at a position 1 / 4 of the top of the transformer in the longitudinal direction and 1 / 4 of the lateral size of the transformer from the tap changer in the lateral direction; the second group of sensors is located directly below the first group of sensors; the fourth group of sensors and the fifth group of sensors are arranged at mirror positions of the first group of sensors and the second group of sensors with respect to the lifting seat.

[0020] As a further description of the present invention, the seventh group of sensors is arranged at a longitudinal distance of 1 / 3 from the top of the transformer and a lateral distance of 1 / 5 from the side of the transformer, the eighth group of sensors is arranged at a longitudinal distance of 2 / 3 from the top of the transformer and a lateral distance of 1 / 5 from the side of the transformer, and the sixth group of sensors is located at a mirror position of the eighth group of sensors.

[0021] As a further description of the present invention, the ninth group of sensors is arranged at a position 1 / 4 of the distance from the top of the transformer in the longitudinal direction, and the tenth group of sensors is arranged at a position 1 / 2 of the distance from the top of the transformer in the longitudinal direction.

[0022] As a further description of the present invention, the eleventh and twelfth groups of sensors are arranged at a longitudinal distance of 1 / 2 from the top of the transformer, the eleventh group of sensors is located to the left of the twelfth group of sensors, the thirteenth and fourteenth groups of sensors are located to the right of the twelfth group of sensors, the thirteenth group of sensors is located directly above the fourteenth group of sensors, the thirteenth group of sensors is arranged at a longitudinal distance of 1 / 3 from the top of the transformer, and the fourteenth group of sensors is arranged at a longitudinal distance of 2 / 3 from the top of the transformer.

[0023] As a further description of the present invention, the fifteenth group of sensors is arranged at the pressure relief valve, the sixteenth group of sensors is arranged at the center of the top of the transformer, and the seventeenth group of sensors is arranged at one side of the tap switch mechanism.

[0024] As a further description of the present invention, the ultrasonic partial discharge sensor adopts an EFPI optical fiber sensor, the ultra-high frequency partial discharge sensor is composed of an antenna, a sensor signal processing module, an optical fiber interface, and a ceramic shell, the antenna adopts a monopole printed structure, the sensor signal processing module adopts a TMS320 digital signal processing module, the optical fiber interface adopts an SFP optical fiber interface, and the ceramic shell has insulation and resistance to insulating oil corrosion.

[0025] As a further description of the present invention, the optical fiber communication system is composed of an optical fiber and an optical receiving module. The optical fiber adopts two single-mode optical fibers and uses wavelength division multiplexing technology to transmit optical signals of multiple wavelengths in the same optical fiber. The optical receiving module adopts a high-sensitivity optical receiving module, which can operate at a lower optical power and provide a clear signal output suitable for long-distance transmission or situations with large signal attenuation.

[0026] As a further description of the present invention, the signal processing circuit is composed of a signal conditioning circuit, a signal conversion circuit and a digital signal processor. The signal conditioning circuit amplifies and filters the two signals collected by the sensor to remove noise and interference and improve the signal-to-noise ratio of the signal. The signal conversion circuit and the digital signal processor are integrated together and use a programmable digital signal processor to extract the amplitude, phase and frequency information from the ultrasonic signal and the ultra-high frequency signal respectively.

[0027] As a further description of the present invention, the sensor array arrangement strategy is designed by combining computer simulation and laboratory fault simulation;

[0028] The signal analysis system designs signal analysis software on the host computer, uses intelligent algorithms to identify and locate signals, and provides fault types to operation and maintenance personnel for equipment maintenance planning;

[0029] The calculation process is as follows:

[0030] When a fault occurs inside the transformer, the faulty part will generate ultrasonic and UHF signals. Since the distance from the faulty part to each sensor is different, there is a time difference in the signals. The distance from the fault point to the sensor is obtained by multiplying the speed of ultrasonic and UHF in oil and solid media by the time difference, and the fault point is located. At the same time, the fault signal is compared with the simulated fault signals in the simulation library and test library to determine the fault type of the faulty part.

[0031] Beneficial effects of the present invention:

[0032] The present invention discloses a transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device, comprising a sensor, an optical fiber communication system, a signal processing circuit, and a signal analysis system. The sensor has 17 groups, each of which comprises an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor. The monitoring device forms an array by arranging the sensors inside the transformer through the 17 groups of sensors on the inner wall of the transformer, thereby reducing the interference of external noise on the sensors, and monitoring the partial discharge signals of the internal windings, core clamps, risers and other parts of the transformer in real time, realizing real-time monitoring of the internal state of the equipment, effectively avoiding the interference of external noise on the sensors, improving the response speed of the monitoring device, and ensuring the safe operation of the transformer.

[0033] The present invention discloses a transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device. The ultrasonic partial discharge sensor adopts an EFPI optical fiber sensor. The EFPI optical fiber sensor can detect weak ultrasonic signals, has high sensitivity, and can timely discover potential problems. At the same time, the optical fiber sensor itself is electrically insulated and will not be affected by the complex electromagnetic environment inside the transformer, thereby ensuring stability and accuracy during long-term operation and avoiding false alarms or missed alarms caused by electromagnetic interference. At the same time, the EFPI optical fiber sensor is small in size and is easy to be built into the transformer for monitoring, thereby reducing the difficulty and cost of installation, improving the accuracy and real-time nature of monitoring, and providing strong support for the maintenance and care of the transformer.

[0034] The present invention provides a transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device. The array arrangement strategy of the 17 groups of sensors is designed by combining computer simulation and laboratory fault simulation. It can realize real-time and accurate monitoring of 26 common faults of the transformer, timely discover and handle problems, and ensure the stable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the general principle diagram of the present invention;

[0036] Figure 2 It is a schematic diagram of the position of the sensor array of the present invention;

[0037] Figure 3It is a schematic diagram of the structure of the EFPI optical fiber sensor of the present invention;

[0038] Figure 4 It is the arrangement diagram of the casing tie rod vibration sensor of the present invention;

[0039] Figure 5 It is the ultrasonic cloud diagram of the casing pull rod vibration of the present invention;

[0040] Figure 6 It is a layout diagram of the casing oil side pressure equalizing ball vibration sensor of the present invention;

[0041] Figure 7 This is the ultrasonic cloud diagram of the vibration of the pressure equalizing ball on the oil side of the casing of the present invention;

[0042] Figure 8 It is the arrangement diagram of the neutral point bushing cable vibration sensor of the present invention;

[0043] Fig. 9 It is the vibration ultrasonic cloud diagram of the neutral point casing cable of the present invention;

[0044] Fig.10 This is a layout diagram of the surface creepage sensor of the outlet device of the present invention;

[0045] Fig.11 This is the ultrasonic cloud diagram of the surface creepage of the outlet device of the present invention;

[0046] Fig.12 It is the arrangement diagram of the discharge sensor at the upper end of the high-voltage winding of the present invention;

[0047] Fig.13 The ultrasonic cloud diagram of the discharge at the upper end of the high-voltage winding of the present invention;

[0048] Fig.14 It is the layout diagram of the discharge sensor in the middle of the high-voltage winding of the present invention;

[0049] Fig.15 This is an ultrasonic cloud diagram of discharge in the middle of the high-voltage winding of the present invention;

[0050] Fig.16 It is the arrangement diagram of the discharge sensor at the lower end of the high voltage winding of the present invention;

[0051] Fig.17 The ultrasonic cloud diagram of the discharge at the lower end of the high-voltage winding of the present invention;

[0052] Fig.18 It is a layout diagram of the discharge sensor at the upper end of the medium voltage winding of the present invention;

[0053] Fig.19 The ultrasonic cloud diagram of the discharge at the upper end of the medium voltage winding of the present invention;

[0054] Fig. 20It is the layout diagram of the medium voltage winding middle discharge sensor of the present invention;

[0055] Fig.21 It is an ultrasonic cloud diagram of discharge in the middle of the medium voltage winding of the present invention;

[0056] Fig. 22 This is the layout diagram of the discharge sensor at the lower end of the medium voltage winding of the present invention

[0057] Fig.23 The ultrasonic cloud diagram of the discharge at the lower end of the medium voltage winding of the present invention;

[0058] Fig.24 It is the layout diagram of the discharge sensor at the upper end of the low voltage winding of the present invention;

[0059] Fig.25 The ultrasonic cloud diagram of the discharge at the upper end of the low-voltage winding of the present invention;

[0060] Fig.26 It is the layout diagram of the discharge sensor in the middle of the low voltage winding of the present invention;

[0061] Fig. 27 It is an ultrasonic cloud diagram of discharge in the middle of the low-voltage winding of the present invention;

[0062] Fig.28 It is the arrangement diagram of the discharge sensor at the lower end of the low-voltage winding of the present invention;

[0063] Fig.29 The ultrasonic cloud diagram of the discharge at the lower end of the low-voltage winding of the present invention;

[0064] Fig.30 It is the arrangement diagram of the low-voltage lead bolt loosening sensor of the present invention;

[0065] Fig.31 It is an ultrasonic cloud diagram of the loosening of the low-voltage lead bolt of the present invention;

[0066] Fig.32 It is a layout diagram of the upper clamping member pull plate vibration sensor of the present invention;

[0067] Fig.33 It is the ultrasonic cloud diagram of the vibration of the upper clamping member pulling plate of the present invention;

[0068] Fig.34 It is a layout diagram of the lower clamping member pull plate vibration sensor of the present invention;

[0069] Fig.35 This is the ultrasonic cloud diagram of the vibration of the lower clamping member pull plate of the present invention;

[0070] Fig.36 It is a layout diagram of the partial discharge sensor between the core clamps of the present invention;

[0071] Fig.37It is an ultrasonic cloud diagram of partial discharge between core clamps of the present invention;

[0072] Fig.38 It is a layout diagram of the upper magnetic shunt suspension discharge sensor of the present invention;

[0073] Fig.39 This is the ultrasonic cloud diagram of the upper magnetic shunt suspension discharge of the present invention;

[0074] Fig.40 It is a layout diagram of the lower magnetic shunt suspension discharge sensor of the present invention;

[0075] Fig.41 This is the ultrasonic cloud diagram of the lower magnetic shunt suspension discharge of the present invention;

[0076] Fig.42 It is the layout diagram of the upper shielding cover loose sensor of the present invention;

[0077] Fig.43 The ultrasonic cloud diagram of the loose upper shielding cover of the present invention;

[0078] Fig.44 It is the arrangement diagram of the lower electrostatic shielding discharge sensor of the present invention;

[0079] Fig.45 It is the ultrasonic cloud diagram of the lower electrostatic shielding discharge of the present invention;

[0080] Fig.46 This is a layout diagram of the bottom pressure pin suspension discharge sensor of the present invention;

[0081] Fig.47 This is the ultrasonic cloud diagram of the suspended discharge of the bottom pressure nail of the present invention;

[0082] Fig.48 It is a layout diagram of the magnetic shielding mechanical vibration sensor of the present invention;

[0083] Fig.49 It is the ultrasonic cloud diagram of magnetic shielding mechanical vibration of the present invention;

[0084] Fig.50 It is the layout diagram of the bias coil discharge sensor of the present invention;

[0085] Fig.51 It is the ultrasonic cloud diagram of the bias coil discharge of the present invention;

[0086] Fig.52 It is a layout diagram of the left side yoke enclosure suspension discharge sensor of the present invention;

[0087] Fig.53 This is the ultrasonic cloud diagram of the suspended discharge of the left side yoke enclosure of the present invention;

[0088] Fig.54It is a layout diagram of the right side yoke enclosure suspension discharge sensor of the present invention;

[0089] Fig.55 This is the ultrasonic cloud diagram of the suspended discharge of the right side yoke enclosure of the present invention. DETAILED DESCRIPTION

[0090] The specific implementation of the present invention is described below in conjunction with the accompanying drawings and embodiments:

[0091] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0092] At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0093] like Figures 1 to 55 As shown, it shows a specific embodiment of the present invention:

[0094] Embodiment 1

[0095] A transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device, including a sensor, an optical fiber communication system, a signal processing circuit, and a signal analysis system.

[0096] There are 17 groups of sensors, each group includes an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor. Each group of sensors is installed inside the transformer through a mounting base to detect partial discharge signals inside the transformer. The sensor converts analog signals into optical signals through an optical fiber communication system and transmits them to a signal processing circuit, which decodes the optical signals and converts them into digital signals. The processing results of the signal processing circuit are processed by a signal analysis system to obtain the location and value of partial discharge inside the transformer, providing data support for operation and inspection personnel to determine the type and severity of internal faults.

[0097] In this embodiment, if Figure 1As shown, there are 17 groups of sensors, each group includes an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor. The monitoring device forms an array of 17 groups of sensors on the inner box wall of the transformer, arranges the sensors inside the transformer, reduces the interference of external noise on the sensors, and monitors the partial discharge signals of the windings, core clamps, risers and other parts of the transformer in real time, realizes real-time monitoring of the internal status of the equipment, effectively avoids the interference of external noise on the sensors, improves the response speed of the monitoring device, and ensures the safe operation of the transformer.

[0098] The 17 groups of sensors are installed inside the transformer in an array.

[0099] The first, second, third, fourth and fifth groups of sensors are arranged on one side of the transformer bushing elevation seat, the first and second groups of sensors are located on the left side of the elevation seat, the third group of sensors are arranged on the elevation seat, and the fourth and fifth groups of sensors are located on the right side of the elevation seat;

[0100] The sixth, seventh and eighth groups of sensors are arranged on one side of the transformer tap switch, and the seventh group of sensors is located directly above the eighth group of sensors;

[0101] The ninth and tenth groups of sensors are arranged on one side of the non-tap switch of the transformer, and the ninth group of sensors is located directly above the tenth group of sensors;

[0102] The eleventh, twelfth, thirteenth and fourteenth groups of sensors are arranged at the radiator position of the transformer;

[0103] The fifteenth group of sensors, the sixteenth group of sensors and the seventeenth group of sensors are arranged on the top of the transformer.

[0104] In this embodiment, if Figure 2 As shown, since sensors are generally not arranged on the bottom of the transformer when they are arranged, the 17 groups of sensors are distributed around and on the top of the transformer. The sensors arranged at these 17 positions can monitor 26 common fault signals of the transformer, detect problems in time and handle them, and ensure the stable operation of the power grid.

[0105] Embodiment 2

[0106] On the basis of the above-mentioned embodiment 1, in order to ensure the accuracy of the monitoring results, the installation positions of the 17 groups of sensors on the transformer are clearly specified, and 26 common transformer faults are accurately detected, and embodiment 2 is specially proposed.

[0107] Specifically, the first group of sensors is arranged at a position 1 / 2 of the top of the transformer in the longitudinal direction and 1 / 4 of the lateral size of the transformer from the tap changer in the lateral direction; the second group of sensors is arranged at a position 1 / 4 of the top of the transformer in the longitudinal direction and 1 / 4 of the lateral size of the transformer from the tap changer in the lateral direction; the second group of sensors is located directly below the first group of sensors; the fourth group of sensors and the fifth group of sensors are arranged at mirror positions of the first group of sensors and the second group of sensors with respect to the lifting seat.

[0108] Specifically, the seventh group of sensors is arranged at a position 1 / 3 of the vertical distance from the top of the transformer and 1 / 5 of the horizontal distance from the side of the transformer. The eighth group of sensors is arranged at a position 2 / 3 of the vertical distance from the top of the transformer and 1 / 5 of the horizontal distance from the side of the transformer. The sixth group of sensors is located at the mirror position of the eighth group of sensors.

[0109] Specifically, the ninth group of sensors is arranged at a position 1 / 4 of the distance from the top of the transformer in the longitudinal direction, and the tenth group of sensors is arranged at a position 1 / 2 of the distance from the top of the transformer in the longitudinal direction.

[0110] Specifically, the eleventh and twelfth groups of sensors are arranged at a longitudinal distance of 1 / 2 from the top of the transformer, the eleventh group of sensors is located on the left side of the twelfth group of sensors, the thirteenth and fourteenth groups of sensors are located on the right side of the twelfth group of sensors, the thirteenth group of sensors is located directly above the fourteenth group of sensors, the thirteenth group of sensors is arranged at a longitudinal distance of 1 / 3 from the top of the transformer, and the fourteenth group of sensors is arranged at a longitudinal distance of 2 / 3 from the top of the transformer.

[0111] Specifically, the fifteenth group of sensors is arranged at the position of the pressure relief valve, the sixteenth group of sensors is arranged at the center position of the top of the transformer, and the seventeenth group of sensors is arranged at a side position of the tap switch mechanism.

[0112] In this embodiment, Figure 2 The following are the exact locations of the 17 sets of sensors. The 26 common transformer faults include 3 types of defects in the bushing, 11 types of defects in the coil, and 12 types of defects in the core accessories.

[0113] Casing component defects: casing tie rod vibration, casing oil side equalizing ball vibration, neutral point casing cable vibration;

[0114] Coil component defects: creepage along the surface of the outlet device, discharge at the upper end of the high-voltage winding, discharge in the middle of the high-voltage winding, discharge at the lower end of the high-voltage winding, discharge at the upper end of the medium-voltage winding, discharge in the middle of the medium-voltage winding, discharge at the lower end of the medium-voltage winding, discharge at the upper end of the low-voltage winding, discharge in the middle of the low-voltage winding, discharge at the lower end of the low-voltage winding, loose low-voltage lead bolts;

[0115] Defects of core accessories: vibration of upper clamp pull plate, vibration of lower clamp pull plate, local discharge between core clamps, suspended discharge of upper magnetic shunt, suspended discharge of lower magnetic shunt, loose upper shielding cover, loose lower shielding cover, suspended discharge of bottom pressure pins, mechanical vibration of magnetic shielding, discharge of bias coil, suspended discharge of left side yoke screen, and suspended discharge of right side yoke screen.

[0116] In this embodiment, the fault is simulated by building the electromagnetic field and physical acoustic field models of the transformer to form a UHF and ultrasonic pulse distribution cloud map.

[0117] like Figure 4 The figure shows the arrangement of the casing tie rod vibration sensor, which is composed of ultrasonic cloud Figure 5 It can be seen that when the casing tie rod vibrates, the sound pressure is mainly concentrated on the plane where the casing is located and the two planes adjacent to the casing. Therefore, two sensors are arranged on the plane where the casing is located and the adjacent planes.

[0118] like Figure 6 The figure shows the arrangement of the pressure equalizing ball vibration sensor on the oil side of the casing. Figure 7 It can be seen that when the pressure equalizing ball on the oil side of the casing vibrates, the sound pressure is mainly concentrated on the plane facing the pressure equalizing ball. The sound pressure on the plane closest to the pressure equalizing ball appears earlier, so two sensors are arranged on this plane. One sensor is arranged on each of the other four planes corresponding to the position of the pressure equalizing ball.

[0119] like Figure 8 The diagram shows the arrangement of the neutral point bushing cable vibration sensor, which is composed of ultrasonic cloud Fig. 9 It can be seen that when the neutral point bushing cable vibrates, the sound pressure is mainly concentrated on the plane directly facing the neutral point bushing cable. The sound pressure on the plane closest to the neutral point bushing cable appears earlier, so two sensors are arranged on this plane. A sensor is arranged on each of the other four planes corresponding to the position of the pressure equalizing ball.

[0120] like Fig.10 The figure shows the layout of the creepage sensor along the outgoing line device, which is composed of ultrasonic cloud Fig.11 It can be seen that the sound pressure is mainly concentrated on the transformer winding, so two sensors are arranged on the top surface closest to it, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0121] like Fig.12 The figure shows the arrangement of the discharge sensor at the upper end of the high voltage winding, which is composed of ultrasonic cloud Fig.13 It can be seen that when discharge occurs at the upper end of the high-voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0122] like Fig.14 The figure shows the layout of the discharge sensor in the middle of the high-voltage winding, which is composed of ultrasonic cloud Fig.15 It can be seen that when discharge occurs in the middle of the high-voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0123] like Fig.16 The figure shows the arrangement of the discharge sensor at the lower end of the high voltage winding, which is composed of ultrasonic cloud Fig.17 It can be seen that when discharge occurs at the lower end of the high-voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0124] like Fig.18 The figure shows the layout of the discharge sensor at the upper end of the medium voltage winding, which is composed of ultrasonic cloud Fig.19 It can be seen that when discharge occurs at the upper end of the medium voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0125] like Fig. 20 The figure shows the layout of the discharge sensor in the middle of the medium voltage winding, which is composed of ultrasonic cloud Fig.21 It can be seen that when discharge occurs in the middle of the medium voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0126] like Fig. 22 The figure shows the layout of the discharge sensor at the lower end of the medium voltage winding. Fig.23 It can be seen that when discharge occurs at the lower end of the medium voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0127] like Fig.24 The figure shows the arrangement of the discharge sensor at the upper end of the low voltage winding, which is composed of ultrasonic cloud Fig.25 It can be seen that when discharge occurs at the upper end of the low-voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0128] like Fig.26 The figure shows the layout of the discharge sensor in the middle of the low-voltage winding, which is composed of ultrasonic cloud Fig. 27 It can be seen that when discharge occurs in the middle of the low-voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0129] like Fig.28 The figure shows the arrangement of the discharge sensor at the lower end of the low voltage winding, which is composed of ultrasonic cloud Fig.29 It can be seen that when discharge occurs at the lower end of the low-voltage winding, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0130] like Fig.30 The following is a diagram of the low voltage lead bolt loosening sensor arrangement, which is provided by ultrasonic cloud Fig.31 It can be seen that when the low-voltage lead bolts loosen, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0131] like Fig.32 The figure shows the layout of the upper clamp pull plate vibration sensor, which is composed of ultrasonic cloud Fig.33 It can be seen that when the upper clamp pull plate vibrates, the sound pressure is mainly concentrated on the upper clamp, so two sensors are arranged on the top surface closest to the upper clamp, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0132] like Fig.34 The following is the layout diagram of the vibration sensor of the lower clamp pull plate, which is composed of ultrasonic cloud Fig.35 It can be seen that when the lower clamp pull plate vibrates, the sound pressure is mainly concentrated on the lower clamp. However, since sensors are usually not arranged on the bottom surface, two sensors are arranged on the side closest to the fault, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0133] like Fig.36 The figure shows the arrangement of partial discharge sensors between core clamps, which are made by ultrasonic cloud Fig.37 It can be seen that when partial discharge occurs between the core clamps, the sound pressure is concentrated on the side cavity of the transformer closest to the core. Therefore, two sensors are arranged on the side closest to the fault, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0134] like Fig.38 The upper magnetic shunt suspension discharge sensor layout is shown, which is composed of ultrasonic cloud Fig.39 It can be seen that when the upper magnetic shunt suspended discharge occurs, the sound pressure is concentrated on the side cavity of the transformer closest to the upper magnetic shunt. Therefore, two sensors are arranged on the side closest to the fault, and one sensor is arranged on each of the remaining surfaces except the bottom.

[0135] like Fig.40The following is the layout of the lower magnetic shunt suspension discharge sensor, which is composed of ultrasonic cloud Fig.41 It can be seen that when the suspended discharge of the lower magnetic shunt occurs, the sound pressure is concentrated on the side cavity of the transformer closest to the lower magnetic shunt. Therefore, two sensors are arranged on the side closest to the fault, and one sensor is arranged on each of the remaining surfaces except the bottom.

[0136] like Fig.42 The upper shield loose sensor layout is shown, which is composed of ultrasonic cloud Fig.43 It can be seen that when the upper shielding cover loosens, the sound pressure is concentrated on the top cavity of the transformer. Therefore, two sensors are arranged on the top surface close to the fault location, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0137] like Fig.44 The following is the layout of the lower electrostatic shield discharge sensor, which is composed of ultrasonic cloud Fig.45 It can be seen that when the lower electrostatic shielding discharge occurs, the sound pressure is mainly concentrated on the transformer winding. Therefore, two sensors are arranged on the top surface closest to the transformer, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0138] like Fig.46 The bottom pressure nail suspension discharge sensor layout is shown, which is composed of ultrasonic cloud Fig.47 It can be seen that when the bottom pressure pin suspended discharge occurs, the sound pressure is concentrated on the transformer cavity adjacent to the bottom pressure pin. Since sensors are usually not arranged on the bottom surface, three sensors are arranged on the side close to the fault, and no sensors are arranged on the other surfaces.

[0139] like Fig.48 The diagram shows the arrangement of magnetically shielded mechanical vibration sensors, which are made of ultrasonic clouds. Fig.49 It can be seen that when magnetic shielding mechanical vibration occurs, the sound pressure is concentrated on the top cavity of the transformer. Therefore, two sensors are arranged on the top surface close to the fault, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0140] like Fig.50 The figure shows the layout of the bias coil discharge sensor, which is composed of ultrasonic cloud Fig.51 It can be seen that when the bias coil discharge occurs, the sound pressure is concentrated on the top cavity of the transformer. Therefore, two sensors are arranged on the top surface close to the fault, and one sensor is arranged on each of the remaining surfaces except the bottom surface.

[0141] like Fig.52 The left side yoke enclosure suspension discharge sensor layout is shown, which is composed of ultrasonic cloud Fig.53 It can be seen that when the suspended discharge of the left side yoke screen occurs, the sound pressure is concentrated on the side cavity of the transformer closest to the fault point. Therefore, two sensors are arranged on the side close to the fault, and one sensor is arranged on each of the other sides.

[0142] like Fig.54 The diagram shows the layout of the right side yoke enclosure suspension discharge sensor, which is composed of ultrasonic cloud Fig.55 It can be seen that when the suspended discharge of the right side yoke screen occurs, the sound pressure is concentrated on the side cavity of the transformer closest to the fault point. Therefore, two sensors are arranged on the side close to the fault, and one sensor is arranged on each of the other sides.

[0143] Based on the above 26 common faults of transformers, the sensor layout array diagram is finally obtained as follows: Figure 2 shown.

[0144] Embodiment 3

[0145] Specifically, the ultrasonic partial discharge sensor adopts an EFPI optical fiber sensor, and its structural schematic diagram is shown as follows: Figure 3 As shown in the figure, the EFPI fiber optic sensor can detect weak ultrasonic signals and has high sensitivity, which can detect potential problems in time. At the same time, the fiber optic sensor itself is electrically insulated and will not be affected by the complex electromagnetic environment inside the transformer, ensuring stability and accuracy during long-term operation and avoiding false alarms or missed alarms caused by electromagnetic interference. At the same time, the EFPI fiber optic sensor is small in size and can be easily built into the transformer for monitoring, which reduces the difficulty and cost of installation, improves the accuracy and real-time nature of monitoring, and provides strong support for the maintenance and maintenance of the transformer.

[0146] The ultra-high frequency partial discharge sensor is composed of an antenna, a sensor signal processing module, an optical fiber interface, and a ceramic shell. The antenna adopts a monopole printed structure, the sensor signal processing module adopts a TMS320 digital signal processing module, the optical fiber interface adopts an SFP optical fiber interface, and the ceramic shell has insulation and resistance to insulating oil corrosion.

[0147] Specifically, the optical fiber communication system is composed of an optical fiber and an optical receiving module. The optical fiber adopts two single-mode optical fibers and uses wavelength division multiplexing technology to transmit optical signals of multiple wavelengths in the same optical fiber. The optical receiving module adopts a high-sensitivity optical receiving module, which can work at a lower optical power and provide a clear signal output suitable for long-distance transmission or situations with large signal attenuation.

[0148] Specifically, the signal processing circuit is composed of a signal conditioning circuit, a signal conversion circuit and a digital signal processor. The signal conditioning circuit amplifies and filters the two signals collected by the sensor to remove noise and interference and improve the signal-to-noise ratio of the signal. The signal conversion circuit and the digital signal processor are integrated together and use a programmable digital signal processor to extract the amplitude, phase and frequency information from the ultrasonic signal and the ultra-high frequency signal respectively.

[0149] Specifically, the sensor array arrangement strategy is designed by combining computer simulation and laboratory fault simulation;

[0150] The signal analysis system designs signal analysis software on the host computer, uses intelligent algorithms to identify and locate signals, and provides fault types to operation and maintenance personnel for equipment maintenance planning;

[0151] The calculation process is as follows:

[0152] When a fault occurs inside the transformer, the faulty part will generate ultrasonic and UHF signals. Since the distance from the faulty part to each sensor is different, there is a time difference in the signals. The distance from the fault point to the sensor is obtained by multiplying the speed of ultrasonic and UHF in oil and solid media by the time difference, and the fault point is located. At the same time, the fault signal is compared with the simulated fault signals in the simulation library and test library to determine the fault type of the faulty part.

[0153] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

[0154] Many other changes and modifications may be made without departing from the concept and scope of the present invention.It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device, characterized in that: Including sensors, optical fiber communication systems, signal processing circuits, signal analysis systems, There are 17 groups of sensors, each group includes an ultrasonic partial discharge sensor and an ultra-high frequency partial discharge sensor. Each group of sensors is installed inside the transformer through a mounting base to detect partial discharge signals inside the transformer. The sensor converts analog signals into optical signals through an optical fiber communication system and transmits them to a signal processing circuit, which decodes the optical signals and converts them into digital signals. The processing results of the signal processing circuit are processed by a signal analysis system to obtain the location and value of partial discharge inside the transformer, providing data support for operation and inspection personnel to determine the type and severity of internal faults. The 17 groups of sensors are installed inside the transformer in an array. The first, second, third, fourth and fifth groups of sensors are arranged on one side of the transformer bushing elevation seat, the first and second groups of sensors are located on the left side of the elevation seat, the third group of sensors are arranged on the elevation seat, and the fourth and fifth groups of sensors are located on the right side of the elevation seat; The sixth, seventh and eighth groups of sensors are arranged on one side of the transformer tap switch, and the seventh group of sensors is located directly above the eighth group of sensors; The ninth and tenth groups of sensors are arranged on one side of the non-tap switch of the transformer, and the ninth group of sensors is located directly above the tenth group of sensors; The eleventh, twelfth, thirteenth and fourteenth groups of sensors are arranged at the radiator position of the transformer; The fifteenth group of sensors, the sixteenth group of sensors and the seventeenth group of sensors are arranged on the top of the transformer.

2. A transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The first group of sensors is arranged at a position 1 / 2 of the top of the transformer in the longitudinal direction and 1 / 4 of the lateral size of the transformer from the tap changer in the lateral direction; the second group of sensors is arranged at a position 1 / 4 of the top of the transformer in the longitudinal direction and 1 / 4 of the lateral size of the transformer from the tap changer in the lateral direction; the second group of sensors is located directly below the first group of sensors; the fourth group of sensors and the fifth group of sensors are arranged at mirror positions of the first group of sensors and the second group of sensors with respect to the lifting seat.

3. A transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The seventh group of sensors is arranged at a longitudinal distance of 1 / 3 from the top of the transformer and a transverse distance of 1 / 5 from the side of the transformer. The eighth group of sensors is arranged at a longitudinal distance of 2 / 3 from the top of the transformer and a transverse distance of 1 / 5 from the side of the transformer. The sixth group of sensors is located at a mirror position of the eighth group of sensors.

4. A transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The ninth group of sensors is arranged at a position 1 / 4 of the distance from the top of the transformer in the longitudinal direction, and the tenth group of sensors is arranged at a position 1 / 2 of the distance from the top of the transformer in the longitudinal direction.

5. The transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The eleventh and twelfth groups of sensors are arranged at a longitudinal distance of 1 / 2 from the top of the transformer, the eleventh group of sensors is located on the left side of the twelfth group of sensors, the thirteenth and fourteenth groups of sensors are located on the right side of the twelfth group of sensors, the thirteenth group of sensors is located directly above the fourteenth group of sensors, the thirteenth group of sensors is arranged at a longitudinal distance of 1 / 3 from the top of the transformer, and the fourteenth group of sensors is arranged at a longitudinal distance of 2 / 3 from the top of the transformer.

6. A transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The fifteenth group of sensors is arranged at the position of the pressure relief valve, the sixteenth group of sensors is arranged at the center position of the top of the transformer, and the seventeenth group of sensors is arranged at a side position of the tap switch mechanism.

7. The transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The ultrasonic partial discharge sensor adopts an EFPI optical fiber sensor, and the ultra-high frequency partial discharge sensor consists of an antenna, a sensor signal processing module, an optical fiber interface, and a ceramic shell. The antenna adopts a monopole printed structure, the sensor signal processing module adopts a TMS320 digital signal processing module, the optical fiber interface adopts an SFP optical fiber interface, and the ceramic shell has insulation and resistance to insulating oil corrosion.

8. The transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The optical fiber communication system is composed of an optical fiber and an optical receiving module. The optical fiber adopts two single-mode optical fibers and uses wavelength division multiplexing technology to transmit optical signals of multiple wavelengths in the same optical fiber. The optical receiving module adopts a high-sensitivity optical receiving module, which can work at a lower optical power and provide a clear signal output suitable for long-distance transmission or situations with large signal attenuation.

9. The transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The signal processing circuit is composed of a signal conditioning circuit, a signal conversion circuit and a digital signal processor. The signal conditioning circuit amplifies and filters the two signals collected by the sensor to remove noise and interference and improve the signal-to-noise ratio of the signal. The signal conversion circuit and the digital signal processor are integrated together and a programmable digital signal processor is used to extract the amplitude, phase and frequency information from the ultrasonic signal and the ultra-high frequency signal respectively.

10. The transformer built-in ultrasonic and ultra-high frequency partial discharge array monitoring device according to claim 1, characterized in that: The sensor array arrangement strategy is designed by combining computer simulation and laboratory fault simulation; The signal analysis system designs signal analysis software on the host computer, uses intelligent algorithms to identify and locate signals, and provides fault types to operation and maintenance personnel for equipment maintenance planning; The calculation process is as follows: When a fault occurs inside the transformer, the faulty part will generate ultrasonic and UHF signals. Since the distance from the faulty part to each sensor is different, there is a time difference in the signals. The distance from the fault point to the sensor is obtained by multiplying the speed of ultrasonic and UHF in oil and solid media by the time difference, and the fault point is located. At the same time, the fault signal is compared with the simulated fault signals in the simulation library and test library to determine the fault type of the faulty part.

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