CN115909880A - A Visual Internal Defect and Fault Verification Test Transformer - Google Patents

Abstract

The invention discloses a visual internal defect and fault verification test transformer, which comprises a simulation transformer body, a partial discharge model and a sensor group, wherein the simulation transformer body is provided with a plurality of sensors; the side wall of an oil tank of the simulation transformer body is provided with a plurality of hand hole observation windows, and a partial discharge model for simulating the faults or defects of the transformer is arranged in the oil tank; the sensor group is used for acquiring development process data of the fault or defect of the transformer when the partial discharge model acts. The transformer can be used for simulating different faults and defects, and various sensors are used for recording process data of various defects from development to breakdown so as to restore the development process of the faults as far as possible. In addition, a large number of hand hole observation windows are arranged, so that an experimenter can conveniently observe the interior of the transformer, and meanwhile, the period and difficulty of defect arrangement, defect failure and defect recovery are greatly shortened.

Description

A Visual Internal Defect and Fault Verification Test Transformer

technical field

The invention belongs to the technical field of power transformers, and in particular relates to a visualized internal defect and fault verification test transformer.

Background technique

As the main equipment in the power grid system, power transformers are of high value, large in number, and widely distributed. Fault outages will bring huge economic losses to grid users, and internal short-circuit faults in transformers may lead to security risks in the grid system. A large number of fault cases show that the existing transformer safety protection system is not perfect, and the physical characteristics of the whole process of defect evolution to fault have not been clearly recognized. It is difficult to establish and perceive relevant characteristic parameters, and it is difficult to form a full chain protection from defect to fault. With the rapid growth of the capacity of the power grid system, the increase of the voltage level of the transformer leads to an increasing capacity, so that the loss caused by the transformer failure is also increasing. Accelerating the understanding and mastering of the transient process of transformer faults, especially the changing law of the internal physical field, is of great significance for isolating faults in advance, avoiding transformer burning and fault expansion. The existing protection mechanism has insufficient understanding of the internal fault transient process of the transformer, especially the change law of the internal physical field. Requirements for transformer multi-physics drive and coupling mechanism under fault and external disturbance, and analysis method and simulation model for accurately describing the dynamic change process of each parameter under transient excitation. Therefore, it is urgent to carry out technical research on the establishment and perception of characteristic parameters related to internal fault defects of power transformers.

In the establishment and perception of characteristic parameters related to internal fault defects of power transformers, and the research on transformer protection technology to reflect internal serious defects or early minor faults, it is difficult to set various internal fault defects, it is difficult to observe the development process of internal defects, and it is difficult to reflect internal serious faults. Problems where transformer protection performance cannot be verified for defects or early minor faults.

Contents of the invention

Purpose of the invention: The purpose of the invention is to provide a visual internal defect and fault verification test transformer.

Technical solution: a visualized internal defect and fault verification test transformer according to the present invention, including a simulated transformer body, a partial discharge model and a sensor group;

The side wall of the fuel tank of the simulated transformer body is provided with a number of hand hole observation windows, and a partial discharge model for simulating transformer faults or defects is arranged in the fuel tank; the sensor group is used for collecting partial discharge models. development process data.

Preferably, the oil tank is connected with a cooling device for adjusting the temperature in the oil tank.

Preferably, the partial discharge model is the fault of impurities in the first line of the high-voltage lead wire, the fault of the spike of the equalizing ball, the discharge fault of the oil gap at the tip of the ground potential, the fault of the lead spike, the creepage fault of the damp cardboard, the fault of the fixed bubble discharge, and the fault of the crimping plate. One or more of suspension faults, bubble injection faults, discharge faults between poles of the iron core, suspension discharge faults of the electrostatic ring, oil flow drive, discharge faults between cakes, and short-circuit faults between electrodes.

Preferably, the partial discharge model is installed at the target position by a detachable device.

Preferably, the sensor group includes at least one of an ultrasonic sensor, a magnetic flux leakage sensor, a high-frequency CT, an optical fiber temperature sensor, an ultrasonic velocity sensor, a pressure sensor, a Vaisala sensor, and a UHF sensor.

Preferably, the sensor group includes ultra-high-frequency sensors for measuring pulse currents arranged on the upper and lower sides of the discharge phase and the sound phase at the projections of the long-axis plane and short-axis plane of the fuel tank.

Preferably, the sensor group includes Vaisala sensors for measuring hydrogen, micro-water and temperature arranged around the gas relay and the A-phase riser seat.

Preferably, the sensor group includes multiple sets of magnetic flux leakage sensors respectively arranged at 1/4, 1/2, and 3/4 of the coil height for measuring the magnetic field distribution inside the transformer.

Preferably, the sensor group includes ultrasonic flow rate sensors respectively arranged on both sides of the connection between the gas connecting pipeline and the outside, and two sets of ultrasonic flow rate sensors are arranged in series in the pipeline, and the ultrasonic flow velocity sensors are used to measure the flow rate of the medium in the pipeline.

Preferably, the sensor group includes pressure sensors for measuring the oil pressure in the fuel tank, and the pressure sensors arranged on the top of the fuel tank are respectively arranged in the middle of the AB phase and the middle of the BC phase; To the middle and the axial center axis and BC phase radial to the middle and the axial center axis; the pressure sensors arranged on the short axis of the oil tank are respectively arranged on the upper and lower sides of the winding axial direction.

Preferably, the ultrasonic sensors are evenly distributed on the long-axis surfaces and short-axis surfaces on both sides of the fuel tank, the number can be determined according to the size of the fuel tank and specific requirements, and the ultrasonic sensors are used to measure partial discharge in the fuel tank.

Preferably, the optical fiber temperature sensor is arranged on the tank wall at the A-phase end of the oil tank, and is installed through the installation flange of the optical fiber through plate, and the optical fiber temperature sensor is used to measure the temperature at the multi-point grounding fault of the winding and iron core.

Preferably, the high-frequency CT is arranged at the existing bushing CTs on the high-voltage side, the medium-voltage side and the low-voltage side.

Preferably, in the partial discharge model, the metal particles are fixed at the lead wire clip of the phase A lead wire through the hand hole of the phase A, and wrapped with a white cloth tape to simulate the impurity fault of the lead wire clip at the head end of the high voltage lead.

Fix the metal spikes on the surface of the pressure equalizing ball of the B phase bushing through the hand hole of phase B with an insulating tape to simulate the fault of the equalizing ball spikes.

By setting the riser seat directly opposite the first line of phase C, the screw enters the interior of the fuel tank through the threaded hole at the bottom of the riser seat, and the adjustment screw is screwed into the inner length of the fuel tank to adjust the distance between the lead line of phase C and the metal tip, simulating the oil gap at the tip of the ground potential Discharge failure.

By arranging metal spikes perpendicular to the bushing toward the observation window at the insulation position of the B-phase and O-phase lead wires on the high-voltage side, the lead wire spike fault is simulated.

Fix the damp cardboard around the lower end of the pressure equalizing ball of the phase A bushing through the hand hole of phase A to simulate the creepage fault of the damp cardboard.

By using an empty capsule to fix the first end of the B-phase lead wire, between the B-phase voltage regulating coil and the high-voltage coil, the fixed bubble discharge fault is simulated.

Fix the metal object on the lower surface of the hand hole cover with an insulating tape through the hand hole at the cover of the A-phase box to simulate the floating fault at the crimping plate.

By setting gas inlets under the core column of phase A, under the iron yoke between phases A and B, and under the surface of the coil enclosure of phase A, insulated pipes of different diameters are used to lead to the required test positions inside the fuel tank to simulate bubble injection faults.

Through the hand hole set directly above the iron core column of phase B, lead out the potential lines between the two poles of the iron core respectively from the two end poles of the iron core, adjust the distance between the potential leads through the hand holes, and simulate the discharge fault between the poles. Fixing bolts for fixing wet cardboard can also be arranged on the lower surface of the box cover, and a lead-out line between poles can be placed on the cardboard to simulate the discharge fault between the poles of the iron core.

The top electrostatic ring is used as the suspension conductor, and the B-phase electrostatic ring and the B-phase high-voltage winding are respectively led to the terminals; when it is necessary to simulate the virtual floating discharge of the electrostatic ring, the insulation of the lead-out wires is released, and the first wire of the B-phase is connected to the B-phase static ring through the lead-out wires And add a package of insulation to simulate the suspension discharge fault of the electrostatic ring.

A ball valve as an air charging interface is installed at the emergency oil drain valve of the lower fuel tank, and the oil circulation is realized by injecting dry air, simulating the oil flow drive.

Two insulating cardboards are used to sandwich the middle insulating cardboard, and a certain amount of metal impurities are placed in the middle insulating cardboard to make a pad to replace part of the middle insulating cardboard to simulate the discharge fault between cakes.

The inter-pole short circuit of the switch is realized by artificially shorting the switch through the hand hole at the switch, and the inter-turn short circuit fault is simulated.

Preferably, the simulated transformer body includes body, iron core, low-voltage winding, medium-voltage winding, high-voltage winding, voltage regulating winding, heat sink, oil conservator, rectifier, on-load tap changer, high-voltage bushing, medium-voltage bushing, The low-voltage bushing, wherein the iron core, low-voltage winding, medium-voltage winding, high-voltage winding and voltage regulating winding are arranged from inside to outside.

Preferably, the cooling device includes an oil pump, a cooling fin and a circulating oil pipe, the cooling fin is connected to the oil tank through the circulating oil pipe, and the oil pump provides power for the circulation of the cooling medium.

Beneficial effects: This kind of test transformer can observe and adjust the defect degree of internal faults, and provides a test platform for observing internal conditions for grasping the transient process of internal faults in the transformer, especially the change law of the internal physical field, and also provides a test platform for developing internal serious defects or The detection of transformer protection performance for early minor faults provides a test platform.

Furthermore, the structure of this test transformer is basically the same as that of the power transformer, combined with the setting simulation method of different fault defects, while completely simulating various internal defect faults of large-scale power transformers, through the sensor group containing multiple types of sensors, it can realize various faults. The whole process of data collection from development to breakdown of such defects can clearly restore the fault development process. In addition, the setting of a large number of hand hole observation windows can meet the needs of test observation, and can also greatly shorten the cycle and difficulty of arranging defect failures and recovering defects.

Description of drawings

Fig. 1 is a front view of the overall structure of a visualized internal defect and fault verification test transformer of the present invention;

Fig. 2 is a top view of the overall structure of a visualized internal defect and fault verification test transformer of the present invention;

Fig. 3 is a side view of the overall structure of a visualized internal defect and fault verification test transformer of the present invention;

Fig. 4 is a schematic internal diagram of a transformer body for a visual internal defect and fault verification test of the present invention.

Detailed ways

The technical solutions of the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

A visual internal defect and fault verification test transformer, including a simulated transformer body, a partial discharge model and a sensor group; a number of hand hole observation windows 12 are provided on the side wall of the oil tank 1 of the simulated transformer body, and the oil tank is provided for simulating transformer faults or defects The partial discharge model; the sensor group is used to collect the data of the development process of the transformer fault or defect when the partial discharge model acts.

In this embodiment, as shown in Figures 1 to 4, the simulated transformer body includes: a body 1, an iron core, a low-voltage winding, a medium-voltage winding, a high-voltage winding, a voltage regulating winding, a high-voltage bushing 7, and a medium-voltage bushing 8 , low-voltage bushing 9, oil conservator 10, on-load tap-changer 11, cooling device, rectifier 90, iron core, low-voltage winding, medium-voltage winding, high-voltage winding and voltage regulating winding are arranged from inside to outside, and the actual power transformer structure Similarly, it can fully simulate various internal defect faults of large power transformers with the partial discharge model.

In this embodiment, the fuel tank is connected to a cooling device for adjusting the temperature in the fuel tank. The cooling device includes an oil pump 61, a cooling fin 60, and a circulating oil pipe 62. According to the temperature requirement in the fuel tank, the oil pump is used to drive the oil to circulate through the circulating oil pipe to dissipate heat. The chip completes the heat dissipation.

In this embodiment, there are 30 hand hole observation windows in the side wall of the fuel tank, 26 on the long axis and 4 on the short axis. The hand hole and observation window are made of transparent toughened glass, and the oil hole is sealed with epoxy resin board.

In this embodiment, the sensor group includes at least one of an ultrasonic sensor 15, a magnetic flux leakage sensor 18, a high-frequency CT, an optical fiber temperature sensor, an ultrasonic velocity sensor 16, a pressure sensor 17, a Vaisala sensor 14, and a UHF sensor 13 Among them, the ultrasonic sensor is used to measure partial discharge, the high-frequency CT is used to measure pulse current, the optical fiber temperature sensor is used to measure the temperature at multi-point grounding faults of windings and iron cores, and the ultrasonic flow rate sensor is used to measure the oil flow rate in the main air pipe connected to the gas relay , The pressure sensor is used to measure the oil pressure in the tank, the Vaisala sensor is used to measure hydrogen, micro water and temperature, and the UHF sensor is used to measure the pulse current.

Further in this embodiment, the arrangement of various sensors in the sensor group is as follows:

A total of 10 UHF sensor interfaces are arranged, of which 8 are placed on the long-axis surface, one on the upper and lower sides of the discharge phase, respectively placed at 1/4 and 3/4 of the axial direction of the winding; one on the upper and lower sides of the healthy phase, respectively Placed at 1/4 and 3/4 of the axial direction of the winding. Place 4 short axis planes, one on each of the upper and lower sides of the two short axis planes. The UHF sensor interface is a circular flange, and an epoxy resin plate is used to seal the oil hole.

There are 2 Vaisala sensor interfaces, which are arranged around the gas relay and the phase A riser respectively.

A total of 10 pressure sensor interfaces are arranged, of which 2 are arranged on the top of the fuel tank, which are respectively arranged in the middle of the AB phase and BC phase; On the axial central axis; set 4 on the short axis, and place one on each short axis at 1/4 and 3/4 of the winding axial direction. Five of the pressure sensor ports are designed as ball valves, and the other 5 ports are designed as straight holes.

A total of two ultrasonic flow velocity sensor interfaces are arranged, which are respectively set at the outer end of the gas connecting pipeline and in the gas connecting pipeline, and the two sets of ultrasonic flow velocity sensors are connected in series.

A total of 10 ultrasonic sensor interfaces are arranged, 8 on the long-axis surface of the fuel tank and 2 on the short-axis surface.

The optical fiber temperature sensor interface is arranged on the tank wall at the A-phase end of the fuel tank, and two optical fiber through-plate installation flanges 21 are welded.

The interface of the magnetic flux leakage sensor is set inside the tank, with 3 rows of mounting brackets, and the height direction is 1/4, 1/2, 3/4 of the coil height; and 4 through-plates are welded on the tank wall at the C-phase end of the fuel tank for installation flange.

High-frequency CTs are placed at the existing bushing CTs on the high-voltage side, medium-pressure side and low-pressure side.

In this embodiment, the partial discharge model is the fault of impurities in the first line of the high-voltage lead wire, the fault of the spike of the equalizing ball, the discharge fault of the oil gap at the tip of the ground potential, the fault of the lead spike, the creepage fault of the damp cardboard, the discharge fault of the fixed air bubble, and the crimping fault. One or more of the floating fault at the board, the bubble injection fault, the discharge fault between the iron core poles, the floating discharge fault of the static ring, the oil flow drive, the discharge fault between the cakes, and the short circuit fault between the poles.

Further in this embodiment, the layout of the partial discharge model is as follows:

Fix copper particles of about 2 microns on the wire clip of the first wire of phase A through the hand hole of phase A, and wrap it with a white cloth tape to simulate the impurity fault of the first end of the high-voltage lead wire.

Fix the metal spikes on the surface of the voltage equalizing ball of the B phase bushing with insulating tape through the hand hole of phase B to simulate the fault of the equalizing ball spikes. The metal spikes are copper wires with a diameter of 2 mm and a length of 10 mm.

By setting the riser 20 directly opposite the first line of phase C, the M6 screw enters the interior of the fuel tank through the threaded hole at the bottom of the riser, and the adjustment screw is screwed into the inner length of the fuel tank to adjust the distance between the lead line of C phase and the metal tip, simulating the tip of ground potential Oil gap discharge failure.

By arranging metal spikes perpendicular to the bushing towards the observation window at the insulation position of the B-phase and O-phase lead wires on the high-voltage side, the lead wire spike fault is simulated. The metal spikes here are copper wires with a diameter of 2 mm and a length of 5 mm.

Fix the damp cardboard to the 20mm lower end of the pressure equalizing ball of the phase A bushing with an insulating rope through the hand hole of phase A to simulate the creepage fault of the damp cardboard.

By using an empty capsule to fix the first end of the B-phase lead wire, between the B-phase voltage regulating coil and the high-voltage coil, the fixed bubble discharge fault is simulated.

Fix the metal object on the lower surface of the hand hole cover with an insulating tape through the hand hole at the cover of the A-phase box to simulate the floating fault at the crimping plate.

Gas input ports 19 are respectively set under the core column of phase A, under the iron yoke between phases A and B, and under the surface of the coil enclosure of phase A, and the insulating pipes of different diameters are used to lead to the required position of the test inside the fuel tank to simulate the bubble injection fault.

Through the hand hole set directly above the iron core column of phase B, lead out the 23 potential wires between the two poles of the iron core respectively from the two end poles of the iron core, adjust the distance between the potential leads through the hand hole, and simulate the discharge fault between the poles. A fixing bolt 24 for fixing wet cardboard can also be arranged on the lower surface of the case cover, and an interpole lead 22 is placed on the cardboard for simulating the discharge fault between the poles of the iron core.

The top electrostatic ring is used as the suspension conductor 24, and the B-phase electrostatic ring and the B high-voltage winding are respectively led to the terminals; when it is necessary to simulate the virtual floating discharge of the electrostatic ring, the insulation of the lead-out wires is released, and the first wire of the B-phase and the B-phase static ring pass through the lead-out wires Connect and add insulation to simulate the floating discharge fault of the electrostatic ring.

A DN50 ball valve as an air charging interface is installed at the emergency oil drain valve of the lower fuel tank, and the oil circulation is realized by injecting dry air, simulating the oil flow drive.

Two 0.5mm insulating cardboards are used to clamp the middle insulating cardboard, and a certain amount of metal impurities are placed in the middle insulating cardboard to make a spacer to replace part of the 3mm insulating cardboard to simulate the discharge fault between cakes.

The inter-pole short circuit of the switch is realized by artificially shorting the switch through the hand hole at the switch, and the inter-turn short circuit fault is simulated.

Since the installation location of the discharge fault between the cakes is the transformer cake room, the discharge fault between the cakes needs to be arranged and repaired by hanging. Other types of partial discharge models can be quickly arranged and repaired through the hand hole observation window.

In summary, this kind of visual internal defect and fault verification test transformer inspection transformer is basically the same as the power transformer structure, provides a variety of fault defect setting simulation methods and various sensor acquisition platforms, and can carry out different fault and defect simulations Arrangement, various sensors can be used to record the process data of various defects from development to breakdown, so as to restore the development process of the fault as much as possible. In addition, the setting of a large number of hand hole observation windows facilitates the experimenter to observe the inside of the transformer, and also greatly shortens the cycle and difficulty of arranging defect faults and recovering defects.

Claims (10)

1. The utility model provides a visual internal defect and failure verification test transformer which characterized in that: the device comprises a simulation transformer body, a partial discharge model and a sensor group;

the side wall of an oil tank of the simulation transformer body is provided with a plurality of hand hole observation windows, and a partial discharge model for simulating the fault or defect of the transformer is arranged in the oil tank; the sensor group is used for collecting development process data of the faults or defects of the transformer when the partial discharge model acts.

2. The visual internal defect and fault verification test transformer of claim 1, wherein: the oil tank is connected with a cooling device for adjusting the temperature in the oil tank.

3. The visual internal defect and fault verification test transformer of claim 1, wherein: the partial discharge model is one or more of a high-voltage lead head clamp impurity fault, a voltage-sharing ball spike fault, a ground potential point oil gap discharge fault, a lead spike fault, a damp paperboard creepage fault, a fixed bubble discharge fault, a compression joint plate suspension fault, a bubble injection fault, an iron core interelectrode discharge fault, an electrostatic ring suspension discharge fault, oil flow driving, an interelectrode discharge fault and an interelectrode short circuit fault.

4. The visual internal defect and fault verification test transformer of claim 3, wherein: the partial discharge model is arranged at the target position through a detachable device.

5. The visual internal defect and fault verification test transformer of claim 1, wherein: the sensor group comprises at least one of an ultrasonic sensor, a magnetic flux leakage sensor, a high-frequency CT (computed tomography), an optical fiber temperature sensor, an ultrasonic flow velocity sensor, a pressure sensor, a Visalat sensor and an ultrahigh-frequency sensor.

6. The visual internal defect and fault verification test transformer of claim 1, wherein: the sensor group comprises ultrahigh frequency sensors which are arranged at the projection positions of the long axial surface and the short axial surface of the oil tank on the upper side and the lower side of the discharging phase and the healthy phase and are used for measuring pulse current.

7. The visual internal defect and fault verification test transformer of claim 1, wherein: the sensor group comprises a Visalat sensor which is arranged around the gas relay and the A-phase lifting seat and is used for measuring hydrogen, micro-water and temperature.

8. The visual internal defect and fault verification test transformer of claim 1, wherein: the sensor group comprises a plurality of groups of magnetic leakage sensors which are respectively arranged at the positions of 1/4, 1/2 and 3/4 of the height of the coil and are used for measuring the distribution of the magnetic field in the transformer.

9. The visual internal defect and fault verification test transformer of claim 1, wherein: the sensor group comprises ultrasonic flow velocity sensors which are respectively arranged on two sides of the gas connecting pipeline and the external connecting part, two groups of ultrasonic flow velocity sensors are connected in series in the pipeline, and the ultrasonic flow velocity sensors are used for measuring the flow velocity of a medium in the pipeline.

10. The visual internal defect and fault verification test transformer of claim 1, wherein: the sensor group comprises pressure sensors for measuring the oil pressure in the oil tank, and the pressure sensors arranged at the top of the oil tank are respectively arranged in the middle of an AB phase and a BC phase; the pressure sensors arranged on the long axial surface of the oil tank are respectively arranged on the AB phase radial middle part and the axial middle axis and the BC phase radial middle part and the axial middle axis; and the pressure sensors arranged on the short axial surface of the oil tank are respectively arranged on the upper side and the lower side of the winding in the axial direction.

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