A generator outlet dry-type voltage transformer test model and its manufacturing method

Abstract

The invention discloses a generator outlet dry-type voltage transformer test model and a manufacturing method thereof, comprising an iron core, a secondary coil insulation frame, a secondary coil, a secondary coil shielding layer, a primary coil insulation frame, a primary coil and an outer insulation layer, wherein the secondary coil insulation frame, the secondary coil, the secondary coil shielding layer, the primary coil insulation frame, the primary coil and the outer insulation layer are sequentially wrapped layer by layer from inside to outside with the iron core as the central axis, the primary coil comprises a plurality of layers of coils, and the primary coil further comprises a high-voltage tail end interlayer tap, a high-voltage tail end turn-to-turn tap, a high-voltage middle interlayer tap, a high-voltage middle turn-to-turn tap, a high-voltage head end interlayer tap and a high-voltage head end turn-to-turn tap; the invention has the advantages of being used for measuring the variation law of the overall parameters of the dry-type voltage transformer, and providing theoretical support for the research on fault diagnosis and insulation detection methods.

Description

Technical Field

[0001] The invention relates to the field of generator outlet PT longitudinal insulation fault diagnosis, and more specifically to a generator outlet dry-type voltage transformer test model and a manufacturing method thereof. Background Art

[0002] Dry-type voltage transformers (hereinafter referred to as "PT") are widely used in power generation enterprises and power systems due to their simple structure, easy maintenance, and reasonable price. For example, at the motor outlet of a power plant, three sets of PTs are generally installed on each machine to provide generator voltage signals to the dual-configuration generator transformer protection, excitation regulator, telecontrol and metering devices. Affected by factors such as design level, casting process, wire quality and operating environment, there have been many abnormal shutdown incidents of units caused by internal insulation failure of PT at the generator outlet in China in recent years. According to incomplete statistics, from 2010 to 2018, more than 30 PT primary winding insulation failures occurred in 12 provinces including Guangdong, Guizhou, Anhui, Shaanxi, Liaoning, Jilin and Inner Mongolia, which seriously affected the power safety production and economic benefits of various power generation enterprises. Therefore, the insulation diagnosis and detection of PTs should be strengthened and the defects should be eliminated in time after handover and commissioning to ensure the safe and stable operation of the power grid.

[0003] Literature survey shows that PT failures in graded insulation structures account for a large proportion, and the fault point is located in the middle and lower part of the primary coil near the inner layer. At present, the main means of testing the inter-turn or inter-layer insulation of the generator outlet PT include DC resistance measurement, no-load current measurement, lightning impulse withstand voltage, triple frequency induction withstand voltage and partial discharge measurement. DC resistance and no-load current are more suitable for post-fault diagnosis, but are not sensitive enough to detect early insulation defects. Lightning impulse withstand voltage is a destructive test, which is currently only carried out in factories. Affected by the distributed capacitance between turns and layers of the primary winding and the capacitance to ground, this method is not effective in detecting defects in the inner coil close to the core. Although the triple frequency withstand voltage test increases the equivalent impedance of the tested coil by increasing the frequency, the test equipment still outputs a large current when a certain voltage is applied, and practical experience shows that the defect detection rate of this method is low. Partial discharge measurement is an effective means of PT defect detection, but it has strict requirements on the electromagnetic environment and is not convenient to carry out on site. In addition, this method has a certain degree of missed detection for coils at low potential, such as: for a fully insulated PT with defects, the A terminal and the N terminal are grounded separately, and the partial discharge amount measured is significantly different. In view of the shortcomings of the above test methods in the field of PT insulation detection, it is necessary to develop new test methods that are convenient for effective insulation assessment on site.

[0004] The research on the inter-turn insulation detection of dry-type air-core reactors and the insulation detection of AC motor stator formed coils using the exponential decay oscillation voltage method is very mature, and high-reliability equipment has been developed and widely used. Compared with the traditional method, the method of using the exponential decay oscillation voltage to detect the insulation of the generator outlet PT has the advantages of good detection effect, simple operation, and strong environmental adaptability. However, there are certain differences between the generator outlet PT and the dry-type air-core shunt reactor, such as large coil DC resistance, large reactance value, large stray capacitance to ground, and interlayer capacitance. The relevant regulations of the exponential decay oscillation test of the inter-turn insulation of the dry-type air-core reactor cannot be copied, and research needs to be carried out on the structure and parameter characteristics of the generator outlet PT. For example, after the insulation fault occurs at different positions, the external parameter change law of the PT; how many frequencies of the exponential decay oscillation voltage can be evenly distributed on the winding of the generator outlet PT, so as to ensure that the assessment intensity of the inter-turn and inter-layer insulation at different positions of the winding is the same, and the inter-turn insulation fault is effectively detected. Therefore, it is necessary to design a dry-type voltage transformer primary coil fault simulation and voltage distribution characteristics test model for the research of new methods for generator outlet PT insulation inspection. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to provide a generator outlet dry-type voltage transformer test model and a manufacturing method thereof to measure the changes in the overall parameters of the PT.

[0006] The present invention solves the above technical problems through the following technical means: comprising an iron core, a secondary coil insulation frame, a secondary coil, a secondary coil shielding layer, a primary coil insulation frame, a primary coil and an outer insulating layer, wherein the secondary coil insulation frame, the secondary coil, the secondary coil shielding layer, the primary coil insulation frame, the primary coil and the outer insulating layer are sequentially wrapped from the inside to the outside with the iron core as the central axis, and the primary coil comprises several layers of coils, and the head end of each layer of coils is connected to the tail end of the next layer of coils of the layer;

[0007] The primary coil also includes a high-voltage tail end interlayer tap, a high-voltage tail end turn-to-turn tap, a high-voltage middle layer tap, a high-voltage middle turn-to-turn tap, a high-voltage head end interlayer tap and a high-voltage head end turn-to-turn tap, wherein the high-voltage tail end interlayer tap and the high-voltage tail end turn-to-turn tap are respectively located at the two ends of the bottom layer of the primary coil, the high-voltage middle layer tap and the high-voltage middle turn-to-turn tap are respectively located at the two ends of the middle layer of the primary coil, the high-voltage head end interlayer tap and the high-voltage head end turn-to-turn tap are respectively located at the two ends of the upper layer of the primary coil, wherein the ends are the side walls of the primary coil parallel to the winding direction of the copper wire.

[0008] The generator outlet dry-type voltage transformer test model is used as a specimen to detect the overall parameter change rules of the high-voltage head end, high-voltage middle end and high-voltage tail end of the faulty dry-type voltage transformer, providing theoretical support for the research on fault diagnosis and insulation detection methods. During the test, the taps in the same group are short-circuited to simulate a short-circuit fault, which can simulate faults in six positions; measurement signals are drawn from the two taps in the same group to measure the distribution of the external applied voltage in the primary coil, providing theoretical support for the research on insulation detection methods.

[0009] Preferably, the iron core is a rectangular structure formed by connecting four cylindrical cores end to end, and the secondary coil insulation frame is wound around the center of one long side of the iron core.

[0010] Preferably, the secondary coil insulation skeleton is highland barley paper, electrical tape and capacitor paper wound layer by layer on the iron core from the inside to the outside, and the secondary coil insulation skeleton is a cylindrical frame.

[0011] Preferably, the secondary coil is a plurality of layers of enameled wires wound on an insulating frame of the secondary coil, and a layer of capacitor paper is wound outside each layer of enameled wire.

[0012] Preferably, the secondary coil shielding layer is capacitor paper, cardboard, electrical tape, conductive self-adhesive tape and semi-conductive crepe paper which is wound around the secondary coil layer by layer from the inside to the outside.

[0013] Preferably, the primary coil insulation skeleton is capacitor paper and paperboard which are wound layer by layer on the secondary coil shielding layer from the inside to the outside.

[0014] Preferably, the primary coil is a plurality of layers of enameled wires wound on an insulating frame of the primary coil, and a layer of capacitor paper is wound outside each layer of enameled wire.

[0015] Preferably, the primary coil has n layers of enameled wire, n is an even number, the first layer of enameled wire and the second layer of enameled wire are the bottom layer of the primary coil, and the Layer of enameled wire and the The first layer of enameled wire is the middle layer of the primary coil, and the n-1th layer of enameled wire and the nth layer of enameled wire are the upper layers of the primary coil.

[0016] The present invention also provides a method for making a test model of a dry-type voltage transformer at an outlet of a generator, the method comprising: selecting an iron core of the same material as the dry-type voltage transformer at the outlet of the generator to be studied, the iron core being a rectangular structure formed by connecting four cylindrical core bodies end to end, winding highland barley paper, electrical tape and capacitor paper layer by layer from the inside to the outside at the center position of a long side of the iron core to form a secondary coil insulation skeleton, winding several layers of enameled wire on the secondary coil insulation skeleton, winding a layer of capacitor paper outside each layer of enameled wire to form a secondary coil, winding capacitor paper, cardboard, electrical tape, conductive self-adhesive tape and semi-conductive crepe paper layer by layer from the inside to the outside outside the secondary coil to form a secondary coil shielding layer, winding capacitor paper and cardboard layer by layer from the inside to the outside outside the secondary coil shielding layer to form a primary coil insulation skeleton, winding several layers of enameled wire layer by layer on the primary coil insulation skeleton, winding a layer of capacitor paper outside each layer of enameled wire to form a primary coil, and winding several layers of capacitor paper outside the primary coil to form an outer insulating layer.

[0017] Preferably, the primary coil has n layers of enameled wire, n is a positive even number, the first layer of enameled wire and the second layer of enameled wire are the bottom layer of the primary coil, Layer of enameled wire and the The first layer of enameled wire is the middle layer of the primary coil, the n-1th layer of enameled wire and the nth layer of enameled wire are the upper layer of the primary coil, and the bottom layer, the middle layer and the upper layer of the primary coil are tapped. The tapping processing method is as follows: the primary coil is wound from the rightmost end of the first layer of enameled wire. During the winding process, after the n-1th layer of enameled wire is wound half a turn, the enameled wire of a preset length is pulled out to the right from the rightmost end, and it is turned back and continued to be wound from right to left until it reaches the leftmost end of the n-1th layer of enameled wire, the enameled wire of a preset length is pulled out to the left from the leftmost end of the n-1th layer of enameled wire, and it is turned back and continued to be wound, and then the enameled wire of a preset length is pulled out from the leftmost end of the n-1th layer of enameled wire, and it is turned back and continued to be wound, and then the enameled wire of a preset length is pulled out from the leftmost end of the n-1th layer of enameled wire. Start winding, after winding half a turn at the leftmost end of the nth layer of enameled wire, pull out a preset length of enameled wire to the left, turn back and continue winding from left to right until reaching the rightmost end of the nth layer of enameled wire, and pull out a preset length of enameled wire to the right at the rightmost end of the nth layer of enameled wire; wherein, the preset length of enameled wire pulled out to the right at the rightmost end of the first layer of enameled wire and the preset length of enameled wire pulled out to the right at the rightmost end of the second layer of enameled wire form a high-voltage tail end interlayer tap, and the preset length of enameled wire pulled out to the left at the leftmost end of the first layer of enameled wire and the preset length of enameled wire pulled out to the left at the leftmost end of the second layer of enameled wire form a high-voltage tail end interturn tap; The preset length of enameled wire drawn to the right from the right end of the first layer of enameled wire is connected to the The preset length of enameled wire drawn to the right from the rightmost end of the first layer of enameled wire forms a high voltage head-end interlayer tap. The preset length of enameled wire drawn to the left from the left end of the first layer of enameled wire The preset length of enameled wire pulled out from the leftmost end of the layer of enameled wire forms a high-voltage head-end interturn tap; the preset length of enameled wire pulled out from the rightmost end of the n-1th layer of enameled wire and the preset length of enameled wire pulled out from the rightmost end of the n-1th layer of enameled wire form a high-voltage head-end interlayer tap, and the preset length of enameled wire pulled out from the leftmost end of the n-1th layer of enameled wire and the preset length of enameled wire pulled out from the leftmost end of the n-1th layer of enameled wire form a high-voltage head-end interturn tap.

[0018] The advantages of the present invention are: using the generator outlet dry-type voltage transformer test model as a sample to detect the overall parameter change law of the high-voltage head end, high-voltage middle part and high-voltage tail end of the faulty dry-type voltage transformer, providing theoretical support for the research of fault diagnosis and insulation detection methods. During the test, the taps in the same group are short-circuited to simulate a short-circuit fault, and faults in six positions can be simulated; the measurement signal is drawn from the two taps in the same group, and the distribution of the externally applied voltage in the primary coil can be measured, providing theoretical support for the research of insulation detection methods. The present invention solves the problem of the lack of a reliable test model for testing the primary coil fault simulation and voltage distribution characteristics of the generator outlet dry-type voltage transformer in the prior art, and promotes the research of PT insulation inspection at the generator outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A front view of a generator outlet dry-type voltage transformer test model disclosed in an embodiment of the present invention;

[0020] Figure 2 A top view of a generator outlet dry-type voltage transformer test model disclosed in an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the winding method of the primary coil of a generator outlet dry-type voltage transformer test model disclosed in an embodiment of the present invention;

[0022] Figure 4 A top view of the tapping process of the primary coil in a method for making a generator outlet dry-type voltage transformer test model disclosed in an embodiment of the present invention;

[0023] Figure 5 It is a cross-sectional view of the tapping process of the primary coil in the method for manufacturing a generator output dry-type voltage transformer test model disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1 and Figure 2 As shown, a generator outlet dry-type voltage transformer test model includes an iron core 8, a secondary coil insulation frame 9, a secondary coil 10, a secondary coil shielding layer 11, a primary coil 13 insulation frame 12, a primary coil 13 and an outer insulation layer 7.

[0026] The iron core 8 is a rectangular structure formed by connecting four cylindrical cores end to end. A secondary coil insulating frame 9 is wound around the center of one long side of the iron core 8. In the embodiment of the present invention, the diameter of the cylindrical core is 85 mm.

[0027] The secondary coil insulation skeleton 9 is made of highland barley paper, electrical tape and capacitor paper wound layer by layer on the iron core 8 from the inside to the outside. The secondary coil insulation skeleton 9 is a cylindrical frame. In the embodiment of the present invention, the cylindrical frame has a tube height of 165 mm and an outer diameter of 88 mm.

[0028] The secondary coil 10 is a plurality of layers of enameled wire wound on the secondary coil insulation frame 9, each layer of enameled wire is wound with a layer of capacitor paper. The enameled wire is selected from enameled wires of the same material and model as the dry-type voltage transformer at the generator outlet to be studied. In the embodiment of the present invention, the total number of turns of the secondary coil 10 is 188, and the total width of the wire arrangement is 135 mm.

[0029] The secondary coil shielding layer 11 is capacitor paper, paperboard, electrical tape, conductive self-adhesive tape and semi-conductive crepe paper wound layer by layer from inside to outside on the secondary coil 10. In the embodiment of the present invention, the secondary coil shielding layer 11 is 165 mm wide and 110 mm in outer diameter.

[0030] The insulating skeleton 12 of the primary coil 13 is capacitor paper and paperboard wound layer by layer on the secondary coil shielding layer 11 from the inside to the outside. In the embodiment of the present invention, the outer diameter of the insulating skeleton 12 of the primary coil 13 is 111 mm.

[0031] The primary coil 13 is n layers of enameled wire wound on the insulating skeleton 12 of the primary coil 13, and a layer of capacitor paper is wound around each layer of enameled wire. The enameled wire is made of the same material and model as the dry-type voltage transformer at the generator outlet to be studied. The outer insulating layer 7 is several layers of capacitor paper wound layer by layer around the primary coil 13. In the embodiment of the present invention, the primary coil 13 has a total of 16,500 turns and 50 layers, with 330 turns in each layer. Each layer is evenly divided into three sections, and the total wiring width is 114 mm. The primary coil 13 has a total of n layers of enameled wire, where n is an even number. The first layer of enameled wire and the second layer of enameled wire are the bottom layers of the primary coil 13, and the second layer of enameled wire is the bottom layer of the primary coil 13. Layer of enameled wire and the The first layer of enameled wire is the middle layer of the primary coil 13, and the n-1th layer of enameled wire and the nth layer of enameled wire are the upper layers of the primary coil 13. The head end of the current layer of the primary coil 13 is connected to the tail end of the next layer of the current layer. Taking the number of turns per layer as an example, the winding diagram between layers and between turns of the primary coil is as follows: Figure 3 The primary coil 13 further includes a high-voltage tail-end interlayer tap 1, a high-voltage tail-end turn-to-turn tap 2, a high-voltage middle-layer tap 3, a high-voltage middle-turn-to-turn tap 4, a high-voltage head-end interlayer tap 5, and a high-voltage head-end turn-to-turn tap 6. The high-voltage tail-end interlayer tap 1 and the high-voltage tail-end turn-to-turn tap 2 are respectively located at the two ends of the bottom layer of the primary coil 13, the high-voltage middle-layer tap 3 and the high-voltage middle-turn-to-turn tap 4 are located at the two ends of the middle layer of the primary coil 13, and the high-voltage head-end interlayer tap 5 and the high-voltage head-end turn-to-turn tap 6 are located at the two ends of the upper layer of the primary coil 13.

[0032] Combination Figure 4 and Figure 5The present invention also provides a method for making a generator outlet dry-type voltage transformer test model, which will introduce in detail the model making process, the tapping method of the primary coil 13, and the specific formation process of the high-voltage tail end interlayer tap 1, the high-voltage tail end turn-to-turn tap 2, the high-voltage middle interlayer tap 3, the high-voltage middle turn-to-turn tap 4, the high-voltage head end interlayer tap 5, and the high-voltage head end turn-to-turn tap 6. The method comprises: selecting an iron core 8 of the same material as the dry-type voltage transformer at the generator outlet to be studied, the iron core 8 being a rectangular structure formed by connecting four cylindrical core bodies end to end, winding highland barley paper, electrical tape and capacitor paper layer by layer from the inside to the outside at the center position of a long side of the iron core 8 to form a secondary coil insulation skeleton 9, winding several layers of enameled wire on the secondary coil insulation skeleton 9, winding a layer of capacitor paper outside each layer of enameled wire to form a secondary coil 10, winding capacitor paper, cardboard, electrical tape, conductive self-adhesive tape and semi-conductive crepe paper layer by layer from the inside to the outside outside the secondary coil 10 to form a secondary coil shielding layer 11, winding capacitor paper and cardboard layer by layer from the inside to the outside outside the secondary coil shielding layer 11 to form a primary coil 13 insulation skeleton 12, winding several layers of enameled wire layer by layer on the primary coil 13 insulation skeleton 12, winding a layer of capacitor paper outside each layer of enameled wire to form a primary coil 13, and winding several layers of capacitor paper outside the primary coil 13 to form an outer insulating layer 7.

[0033] The primary coil 13 has n layers of enameled wire, where n is a positive even number. The first layer of enameled wire and the second layer of enameled wire are the bottom layers of the primary coil 13. Layer of enameled wire and the The first layer of enameled wire is the middle layer of the primary coil 13, the n-1th layer of enameled wire and the nth layer of enameled wire are the upper layer of the primary coil 13, the bottom layer of the primary coil 13, the middle layer of the primary coil 13 and the upper layer of the primary coil 13 are tapped, and the tapping processing method is: the primary coil 13 starts to be wound from the rightmost end of the first layer of enameled wire, and during the winding process, after the n-1th layer of enameled wire is wound half a turn, the enameled wire of a preset length is pulled out to the right from the rightmost end, and it is turned back and continued to be wound from right to left until it reaches the leftmost end of the n-1th layer of enameled wire, the enameled wire of a preset length is pulled out to the left from the leftmost end of the n-1th layer of enameled wire, and it is turned back and continued to be wound, and then the enameled wire of a preset length is pulled out from the leftmost end of the n-1th layer of enameled wire, and it is turned back and continued to be wound, and then the enameled wire of a preset length is pulled out from the nth layer of enameled wire. The winding starts from the leftmost end of the enameled wire, and after the leftmost end of the nth layer of enameled wire is wound half a turn, a preset length of enameled wire is pulled out to the left, and the winding is continued from left to right until the rightmost end of the nth layer of enameled wire is reached, and the enameled wire of the preset length is pulled out to the right from the rightmost end of the nth layer of enameled wire; wherein, the enameled wire of the preset length pulled out to the right from the rightmost end of the first layer of enameled wire and the enameled wire of the preset length pulled out to the right from the rightmost end of the second layer of enameled wire form a high-voltage tail-end interlayer tap 1, and the enameled wire of the preset length pulled out to the left from the leftmost end of the first layer of enameled wire and the enameled wire of the preset length pulled out to the left from the leftmost end of the second layer of enameled wire form a high-voltage tail-end interturn tap 2; The preset length of enameled wire drawn to the right from the right end of the first layer of enameled wire is connected to the The enameled wire of the preset length drawn to the right from the rightmost end of the first layer of enameled wire forms a high voltage head-end interlayer tap 5. The preset length of enameled wire drawn to the left from the left end of the first layer of enameled wire The preset length of enameled wire pulled out from the leftmost end of the layer of enameled wire forms a high-voltage head-end interturn tap 6; the preset length of enameled wire pulled out from the rightmost end of the n-1th layer of enameled wire and the preset length of enameled wire pulled out from the rightmost end of the n-1th layer of enameled wire form a high-voltage head-end interlayer tap 5, and the preset length of enameled wire pulled out from the leftmost end of the n-1th layer of enameled wire and the preset length of enameled wire pulled out from the leftmost end of the n-1th layer of enameled wire form a high-voltage head-end interturn tap 6.

[0034] Taking the primary coil 13 with 16500 turns as an example, the winding method of the primary coil 13 is introduced. The starting position of the primary coil 13 is located at the rightmost side of the first section of the first layer of enameled wire. The tail end of the first layer of enameled wire is made into a lead end as the low-voltage lead wire of the primary coil 13. After the first layer of enameled wire is wound 0.5 turns, it is tapped to the right (20mm long), and then it is folded back to continue winding. After winding 110 turns, a layer of capacitor paper with a width of 125mm is wound; after continuing to wind 110 turns, another layer of capacitor paper with a width of 125mm is wound; continue to wind, tap the left at the 329.5 turn position (20mm long), fold back and continue to wind; after the first layer of coil reaches 330 turns, a layer of capacitor paper with a width of 125mm is wound, and then the second layer of coil is wound from left to right; After the 330.5th turn position taps to the left (20mm long), fold back and continue winding; after the second layer of coil is wound 110 turns, a layer of capacitor paper with a width of 125mm is wound; after another 110 turns, another layer of capacitor paper with a width of 125mm is wound; continue winding, tap the right position (20mm long) at the 659.5th turn position, fold back and continue winding; after the second layer of coil reaches 330 turns and a layer of capacitor paper with a width of 125mm is wound, start winding the third layer of coil from right to left. At this time, the taps at the 0.5th turn and the 659.5th turn position form a pair of primary coil 13 high-voltage tail end interlayer taps 1, and the taps at the 329.5th turn and the 330.5th turn position form a pair of primary coil 13 high-voltage tail end interturn taps 2.

[0035] After the third layer of coil is wound with 110 turns, a layer of capacitor paper with a width of 125mm is wound; after continuing to wind 110 turns, another layer of capacitor paper with a width of 125mm is wound; after the third layer of coil reaches 330 turns, a layer of capacitor paper with a width of 125mm is wound, and then the fourth layer of coil is wound from left to right; after the fourth layer of coil is wound with 110 turns, a layer of capacitor paper with a width of 125mm is wound; after continuing to wind 110 turns, another layer of capacitor paper with a width of 125mm is wound; after the fourth layer of coil reaches 330 turns, a layer of capacitor paper with a width of 125mm is wound, and then the fifth layer of coil is wound from right to left; and this process is repeated until the 24th layer is wound.

[0036] The 24th layer is wound, that is, after the 7920th turn is wound, a layer of capacitor paper with a width of 125mm is wound, and then the 25th layer of coil is wound from right to left. After winding to 7920.83 turns, it taps to the right (20mm long), then turns back and continues to wind. After the 25th layer of coil is wound 110 turns, a layer of capacitor paper with a width of 125mm is wound; after continuing to wind 110 turns, another layer of capacitor paper with a width of 125mm is wound; continue to wind, tap to the left at the 8249.83th turn position (20mm long), turn back and continue to wind; after the 25th layer of coil reaches 330 turns, a layer of width is wound. The 26th coil is wound from left to right with capacitor paper having a width of 125mm; after the 8250.83rd turn position is tapped to the left (20mm long), the coil is folded back and continued to be wound; after the 26th coil is wound with 110 turns, a layer of capacitor paper having a width of 125mm is wound; after another 110 turns, another layer of capacitor paper having a width of 125mm is wound; the coil is continued to be wound, and after the 8579.83rd turn position is tapped to the right (20mm long), the coil is folded back and continued to be wound; after the 26th coil reaches 330 turns, a layer of capacitor paper having a width of 125mm is wound, and the 27th coil is started to be wound from right to left. At this time, the taps at the 7920.83rd turn and the 8579.83rd turn position form a pair of high-voltage middle layer interlayer taps 3 of the primary coil 13, and the taps at the 8249.83rd turn and the 8250.83rd turn position form a pair of high-voltage middle turn interturn taps 4 of the primary coil 13.

[0037] After the 27th layer of coil is wound with 110 turns, a layer of capacitor paper with a width of 125mm is wound; after continuing to wind 110 turns, another layer of capacitor paper with a width of 125mm is wound; after the 27th layer of coil reaches 330 turns, a layer of capacitor paper with a width of 125mm is wound, and then the 28th layer of coil is wound from left to right; after the 4th layer of coil is wound with 110 turns, a layer of capacitor paper with a width of 125mm is wound; after continuing to wind 110 turns, another layer of capacitor paper with a width of 125mm is wound; after the 28th layer of coil reaches 330 turns, a layer of capacitor paper with a width of 125mm is wound, and then the 29th layer of coil is wound from right to left; and this process is repeated until the 48th layer is wound.

[0038] The 48th layer is wound, that is, after the 15840th turn is wound, a layer of capacitor paper with a width of 125mm is wound, and then the 49th layer of coil is wound from right to left. After winding to 15840.17 turns, it is tapped to the right (20mm long), and then it is folded back to continue winding. After 110 turns of the 49th layer of coil, a layer of capacitor paper with a width of 125mm is wound; after continuing to wind 110 turns, another layer of capacitor paper with a width of 125mm is wound; continue to wind, tap the left at the 16169.17th turn position (20mm long), fold back and continue to wind; after the 49th layer of coil reaches 330 turns, a layer of capacitor paper with a width of 125mm is wound Paper, start to wind the 50th layer of coil from left to right; after tapping left at the 16170.17 turn position (20mm long), fold back and continue winding; after 110 turns of the 50th layer of coil, wrap a layer of capacitor paper with a width of 125mm; after continuing to wind 110 turns, wrap another layer of capacitor paper with a width of 125mm; continue winding, after tapping right at the 16499.17 turn position (20mm long), fold back and continue winding; after the 50th layer of coil reaches 330 turns, that is, the total number of turns reaches 1650 turns, wind multiple layers of capacitor paper as the external insulation layer 7 of the primary coil 13, and make lead ends as the high-voltage lead-out wires of the primary coil 13. At this time, the taps at the positions of the 15840.17th turn and the 16499.17th turn form a pair of primary coil 13 high voltage head end interlayer taps 5, and the taps at the positions of the 16169.17th turn and the 16170.17th turn form a pair of primary coil 13 high voltage head end interturn taps 6. At this point, the test model is completed.

[0039] Through the above technical scheme, the present invention provides a generator outlet dry-type voltage transformer test model and a manufacturing method thereof. The generator outlet dry-type voltage transformer test model is used as a sample to detect the overall parameter change law of the high-voltage head end, high-voltage middle part and high-voltage tail end of the faulty dry-type voltage transformer, providing theoretical support for the research on fault diagnosis and insulation detection methods. During the test, the taps in the same group are short-circuited to simulate a short-circuit fault, and faults in six positions can be simulated; measurement signals are drawn from the two taps in the same group, and the distribution of the external applied voltage in the primary coil 13 can be measured, providing theoretical support for the research on insulation detection methods.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A generator outlet dry-type voltage transformer test model, characterized in that: It includes an iron core, a secondary coil insulation frame, a secondary coil, a secondary coil shielding layer, a primary coil insulation frame, a primary coil and an outer insulation layer, wherein the secondary coil insulation frame, the secondary coil, the secondary coil shielding layer, the primary coil insulation frame, the primary coil and the outer insulation layer are sequentially wrapped from the inside to the outside with the iron core as the central axis, and the primary coil includes several layers of coils, and the head end of each layer of coils is connected to the tail end of the next layer of coils of the layer; The primary coil further includes a high-voltage tail-end interlayer tap, a high-voltage tail-end turn-to-turn tap, a high-voltage middle-layer tap, a high-voltage middle-turn-to-turn tap, a high-voltage head-end interlayer tap, and a high-voltage head-end turn-to-turn tap, wherein the high-voltage tail-end interlayer tap and the high-voltage tail-end turn-to-turn tap are respectively located at two ends of the bottom layer of the primary coil, the high-voltage middle-layer tap and the high-voltage middle-turn-to-turn tap are respectively located at two ends of the middle layer of the primary coil, and the high-voltage head-end interlayer tap and the high-voltage head-end turn-to-turn tap are respectively located at two ends of the upper layer of the primary coil, wherein the ends are side walls on the primary coil parallel to the winding direction of the copper wire; The secondary coil insulation frame is made of highland barley paper, electrical tape and capacitor paper wound layer by layer on the iron core from the inside to the outside, and the secondary coil insulation frame is a cylindrical frame; The secondary coil is composed of several layers of enameled wires wound on the insulating frame of the secondary coil, and each layer of enameled wire is wound with a layer of capacitor paper; The secondary coil shielding layer is capacitor paper, paperboard, electrical tape, conductive self-adhesive tape and semi-conductive crepe paper wound around the secondary coil layer by layer from the inside to the outside; The primary coil insulation frame is capacitor paper and paperboard wound layer by layer on the secondary coil shielding layer from the inside to the outside; The primary coil is composed of several layers of enameled wires wound on the primary coil insulation frame, and each layer of enameled wire is wound with a layer of capacitor paper; The primary coil has n layers of enameled wire, n is an even number, the first layer of enameled wire and the second layer of enameled wire are the bottom layer of the primary coil, and the Layer of enameled wire and the The first layer of enameled wire is the middle layer of the primary coil, and the n-1th layer of enameled wire and the nth layer of enameled wire are the upper layers of the primary coil.

2. A generator outlet dry-type voltage transformer test model according to claim 1, characterized in that: The iron core is a rectangular structure formed by connecting four cylindrical cores end to end, and a secondary coil insulation frame is wound around the center of one long side of the iron core.

3. A method for making a generator outlet dry-type voltage transformer test model according to any one of claims 1-2, characterized in that: The method comprises: selecting an iron core of the same material as that of the dry-type voltage transformer at the generator outlet to be studied, wherein the iron core is a rectangular structure formed by connecting four cylindrical core bodies end to end, winding highland barley paper, electrical tape and capacitor paper layer by layer from the inside to the outside at the center position of a long side of the iron core to form a secondary coil insulation skeleton, winding several layers of enameled wire on the secondary coil insulation skeleton, winding a layer of capacitor paper outside each layer of enameled wire to form a secondary coil, winding capacitor paper, cardboard, electrical tape, conductive self-adhesive tape and semi-conductive crepe paper layer by layer from the inside to the outside outside the secondary coil to form a secondary coil shielding layer, winding capacitor paper and cardboard layer by layer from the inside to the outside outside the secondary coil shielding layer to form a primary coil insulation skeleton, winding several layers of enameled wire layer by layer on the primary coil insulation skeleton, winding a layer of capacitor paper outside each layer of enameled wire to form a primary coil, and winding several layers of capacitor paper outside the primary coil to form an outer insulating layer.

4. The method for making a generator outlet dry-type voltage transformer test model according to claim 3 is characterized in that: The primary coil has n layers of enameled wire, where n is a positive even number. The first layer of enameled wire and the second layer of enameled wire are the bottom layers of the primary coil. Layer of enameled wire and the The first layer of enameled wire is the middle layer of the primary coil, the n-1th layer of enameled wire and the nth layer of enameled wire are the upper layer of the primary coil, and the bottom layer, the middle layer and the upper layer of the primary coil are tapped. The tapping processing method is as follows: the primary coil is wound from the rightmost end of the first layer of enameled wire. During the winding process, after the n-1th layer of enameled wire is wound half a turn, the enameled wire of a preset length is pulled out to the right from the rightmost end, and it is turned back and continued to be wound from right to left until it reaches the leftmost end of the n-1th layer of enameled wire, the enameled wire of a preset length is pulled out to the left from the leftmost end of the n-1th layer of enameled wire, and it is turned back and continued to be wound, and then the enameled wire of a preset length is pulled out from the leftmost end of the n-1th layer of enameled wire, and it is turned back and continued to be wound, and then the enameled wire of a preset length is pulled out from the leftmost end of the n-1th layer of enameled wire. Start winding, after winding half a turn at the leftmost end of the nth layer of enameled wire, pull out a preset length of enameled wire to the left, turn back and continue winding from left to right until reaching the rightmost end of the nth layer of enameled wire, and pull out a preset length of enameled wire to the right at the rightmost end of the nth layer of enameled wire; wherein, the preset length of enameled wire pulled out to the right at the rightmost end of the first layer of enameled wire and the preset length of enameled wire pulled out to the right at the rightmost end of the second layer of enameled wire form a high-voltage tail end interlayer tap, and the preset length of enameled wire pulled out to the left at the leftmost end of the first layer of enameled wire and the preset length of enameled wire pulled out to the left at the leftmost end of the second layer of enameled wire form a high-voltage tail end interturn tap; The preset length of enameled wire drawn to the right from the right end of the first layer of enameled wire is connected to the The enameled wire of the preset length drawn to the right from the rightmost end of the first layer of enameled wire forms a high voltage head-end interlayer tap. The preset length of enameled wire drawn to the left from the left end of the first layer of enameled wire The preset length of enameled wire pulled out from the leftmost end of the layer of enameled wire forms a high-voltage head-end interturn tap; the preset length of enameled wire pulled out from the rightmost end of the n-1th layer of enameled wire and the preset length of enameled wire pulled out from the rightmost end of the n-1th layer of enameled wire form a high-voltage head-end interlayer tap, and the preset length of enameled wire pulled out from the leftmost end of the n-1th layer of enameled wire and the preset length of enameled wire pulled out from the leftmost end of the n-1th layer of enameled wire form a high-voltage head-end interturn tap.

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