WO2016095127A1

WO2016095127A1 - Insulation dielectric response test system

Info

Publication number: WO2016095127A1
Application number: PCT/CN2014/094103
Authority: WO
Inventors: 吕彦冬; 杨丽君; 廖瑞金; 高竣; 刘捷丰; 刘骁
Original assignee: 阿尔斯通技术有限公司; 吕彦冬
Priority date: 2014-12-17
Filing date: 2014-12-17
Publication date: 2016-06-23

Abstract

An insulation dielectric response test system comprises: a housing (101); a support (102), disposed in the housing (101) and fixed on the bottom of the housing (101); a first electrode (103), disposed in the housing (101); a second electrode (104), disposed on the support (102) and located below the first electrode (103); and a tested sample (105), disposed between the first electrode (103) and the second electrode (104); multiple positioning rods (106) having graduations, vertically disposed at the edge of the support (102) and used for fixing the tested sample (105), wherein each positioning rod (106) is in threaded connection to at least one pair of nuts (107), and the tested sample (105) is clamped between one pair of nuts (107); and a vacuum-pumping device (200), wherein the vacuum-pumping device (200) further comprises a cavity (201) adapted to accommodating the housing (101) and a first valve (202) disposed on the cavity (201) and adapted to being externally connected to a vacuum pump. The insulation dielectric response test system has reliable performance and can precisely control the dimensional scales of an oil channel and insulation paper, so as to simulate oil and paper barrier structures of all kinds of oil-immersed power transformers. In addition, the insulation dielectric response test system can also solve the problem of poor repeatability of oil paper insulation dielectric response tests.

Description

Insulation dielectric response test system

Technical field

The invention relates to the field of insulation aging and life prediction of electrical equipment, in particular to an insulation dielectric response test system.

Background technique

In recent years, dielectric response technology has been widely studied due to its simple operation and rich carrying insulation information, especially its strong anti-interference ability. It has received extensive attention in the field of transformer oil-paper insulation diagnosis. In order to better apply the dielectric response technology in the laboratory to study the diagnosis method of transformer oil-paper insulation, it is necessary to simulate the oil-paper insulation structure of the transformer equivalently in the laboratory to obtain accurate dielectric response information of the oil-paper insulation, and the existing test Electrodes, at least the following problems and shortcomings during the test:

(1) The position of the test sample between the electrodes cannot be fixed, which may cause the upper and lower electrodes to directly contact the short circuit, and the repeatability may also be affected;

(2) Bubbles will appear between the oil and paper during the test, resulting in poor repeatability of the dielectric response curve;

(3) It is impossible to accurately control the size ratio of the oil passage and the insulating paper, thereby simulating a plurality of transformer main insulation structures.

Summary of the invention

The inventors of the present invention have devised a novel insulating medium in view of various problems existing in the prior art oil-paper insulating dielectric response test, such as poor repeatability, difficulty in controlling the size ratio of the oil passage and the insulating paper, and the like. The electrical response test system, which can better simulate the oil and paper barrier structure of the oil-immersed power transformer, improves the repeatability of the test and easily controls the size ratio of the oil passage and the insulating paper.

Specifically, the present invention provides an insulating dielectric response test system comprising:

case;

a holder disposed in the housing and fixed to a bottom of the housing;

a first electrode disposed in the housing;

a second electrode disposed on the support and located below the first electrode;

The sample to be tested is disposed between the first electrode and the second electrode;

a plurality of scaled positioning rods are vertically disposed at the edge of the support for fixing the sample to be tested, and each of the positioning screws is threaded with at least one pair of nuts, wherein the sample to be tested is clamped Between a pair of nuts; and

The vacuuming device, wherein the vacuuming device further comprises: a cavity adapted to receive the housing and a first valve disposed on the cavity and adapted to externally connect a vacuum pump.

Preferably, in the above insulation dielectric response test system, the positioning rod and the support are made of polytetrafluoroethylene.

Preferably, in the above dielectric dielectric response test system, the vacuuming device further comprises a second valve adapted to be coupled to a vacuum pressure gauge.

Preferably, in the above insulation dielectric response test system, the top of the housing has an opening, wherein one end of the rod is connected to the first electrode, and the other end of the rod extends through the opening. Outside the housing and adapted to connect a weight outside the housing.

Preferably, in the above insulation dielectric response test system, the weight is a copper cake having a screw hole at the center, and the other end of the pole has a thread matching the screw hole.

Preferably, in the above insulation dielectric response test system, the pole is a conductive rod whose one end is in electrical contact with the first electrode.

Preferably, in the above-described insulating dielectric response test system, the housing has a sealing hole that is fitted to the same sealing plug.

Preferably, in the above insulation dielectric response test system, the strut is provided with a pair of nuts, one of the pair of nuts is located outside the casing, and the other of the pair of nuts is located in the casing The body is provided with a corresponding threaded structure to allow the spacing between the first electrode and the sample to be tested to be adjusted by the cooperation of the pair of nuts and the threaded structure.

Preferably, in the above insulation dielectric response test system, the protective electrode is further disposed on the support, wherein the protection electrode surrounds the second electrode and exposes an upper surface of the second electrode.

Preferably, in the above insulation dielectric response test system, the cavity is made of stainless steel.

In summary, the present invention provides a reliable dielectric dielectric response test system. The system accurately controls the size ratio of the oil passage and the insulating paper to simulate the oil of various oil-immersed power transformers. Paper barrier structure. In addition, the insulating dielectric response test system of the present invention can also solve the problem of poor repeatability of the oil-paper insulation dielectric response test.

The foregoing description of the preferred embodiments of the present invention

DRAWINGS

The accompanying drawings are included to provide a further understanding of the embodiments of the invention In the figure:

Figure 1 schematically illustrates an embodiment of an aspect of an insulating dielectric response test system in accordance with the present invention.

Fig. 2 schematically shows an embodiment of another aspect of an insulating dielectric response test system in accordance with the present invention.

detailed description

Embodiments of the present invention will now be described in detail with reference to the drawings. Reference will now be made in detail to the preferred embodiments embodiments of the invention Wherever possible, the same reference numerals reference Further, although the terms used in the present invention are selected from well-known public terms, some of the terms mentioned in the specification of the present invention may be selected by the applicant according to his or her judgment, and the detailed meaning thereof is herein. The description of the relevant part of the description. Furthermore, it is intended that the present invention be understood not only by the actual terms used, but also by the meaning of each term.

Figure 1 schematically illustrates an aspect in accordance with the present invention. In particular, the preferred embodiment of the invention is shown in FIG. 1 and is not intended to limit the invention.

Referring to the embodiment shown in FIG. 1, the insulating dielectric response test system of the present invention includes at least a housing 101, a holder 102, a first electrode 103, a second electrode 104, and a sample 105 to be tested.

The material of the casing 101 may be made of plexiglass to facilitate observation of the relevant scales, readings, and positions of the components inside the casing 101 from the outside.

The holder 102, the first electrode 103, the second electrode 104, and the sample to be tested 105 are all placed in the housing 101. The holder 102 is fixed to the bottom of the housing 101. The bottom or side of the holder 102 can be apertured for easy exit from the second electrode 104.

The first electrode 103 serves as a high voltage electrode. The second electrode 104 serves as a test electrode which is placed on the holder 102 and below the first electrode 103. The material of the second electrode 104 may be brass, which is connected to the terminal 115 via an opening at the bottom or side of the holder 102, and then may be further connected to the measuring line of the test instrument.

In another aspect, the insulating dielectric response test system of the present invention can further include a guard electrode 113 disposed on the support 102. The guard electrode 113 surrounds the second electrode 104 and exposes only the upper surface of the second electrode 104. The guard electrode 113 can prevent leakage current from flowing through the surface of the test sample 105.

A sample 105 to be tested, such as a single-layer insulating paperboard, is disposed between the first electrode 103 and the second electrode 104.

Preferably, in the preferred embodiment described above, the insulating dielectric response test system may further include a plurality of positioning rods 106, such as four positioning rods 106. As shown in FIG. 1, these positioning rods 106 are vertically disposed at the edge of the holder 102 for fixing the sample 105 to be tested. For example, the positioning rod 106 can pass through the four corners of the sample 105 being tested, thereby fixing the sample 105 to be tested and limiting its position in the horizontal direction.

More preferably, the positioning rod 106 can adopt a positioning screw marked with a scale, and each positioning screw is screwed with at least one pair of nuts 107. For example, the four corners of the sample 105 to be tested may be sandwiched between four pairs of nuts 107 distributed over the four positioning screws 106 at the four corners of the support 102, respectively. Alternatively, the positioning screw 106 may be passed through the four corners of the sample 105 to be tested while the four corners of the sample 105 to be tested are respectively clamped to the four positioning screws distributed at the four corners of the support 102. Between the four pairs of nuts 107 on 106. Since the positioning screw 106 is marked with a scale, the height of the vertical direction of the sample to be tested 105 can be adjusted conveniently and accurately. Thus, the oil gap of the desired thickness can be retained between the test sample 105 and the second electrode 104 by adjusting the position of the nut 107 on the positioning screw 106. Of course, the present invention is not particularly limited in the number of positioning screws and their setting positions, and those skilled in the art can also appropriately adjust within the scope of the present invention to achieve the same or similar effects.

The above-mentioned positioning rod 106 and the support 102 are preferably made of polytetrafluoroethylene in consideration of the fact that they are immersed in the oil at the time of use.

Further, in the insulating dielectric response test system of the present invention, the top of the casing 101 may have an opening 108 and a rod 109. One end of the strut 109 is in contact with the first electrode 103. The other end of the strut 109 extends outside the casing 101 via the opening 108 and is adapted to connect a weight 110 outside the casing 101. The weight 110 may be, for example, a copper cake having a screw hole at the center, and correspondingly, the top of the other end of the rod 109 has a thread matching the screw hole. Thus, the copper cake 110 can be mounted together with the struts 109. Thus, the weight 110 can be connected to the first electrode 103, increase the weight of the first electrode 103, and press the sample 105 to be tested, so that the first electrode 103 is in good contact with the sample 105 to be tested.

Preferably, the strut 109 is a conductive rod whose one end is in electrical contact with the first electrode 103. Thus, electrical connection can be made to the first electrode 103 via the struts 109. For example, the terminal of the first electrode 103 may be formed at a position marked by reference numeral 109 in Fig. 1 to be connected to a high voltage line of the measuring device.

Preferably, the strut 109 is provided with a pair of nuts 114, one of which is located outside the casing 101 and the other is located in the casing 101, and the strut 109 is provided with a corresponding thread structure, as shown in FIG. Show. Thus, the thickness of the oil gap between the first electrode 103 (high voltage electrode) and the measurement sample 105 can be changed by adjusting the pair of nuts 114.

In addition, the housing 101 can also have a sealing hole 111. The sealing holes 111 are fitted to the sealing plugs 112. The sealing plug 112 may be made of plexiglass, opened during vacuum pumping, and closed after pumping to prevent external moisture from entering the structure shown in FIG.

In Fig. 1, a pair of symmetrically arranged terminals 116 may also be provided for connecting the wiring of the second electrode 104 and the guard electrode 113 to the external wiring.

Turning now to Figure 2, Figure 2 schematically illustrates another aspect of an insulating dielectric response test system in accordance with the present invention. Also, the preferred embodiment of the present invention is shown in FIG. 2 and is not intended to limit the invention.

In this embodiment, the insulating dielectric response test system of the present invention may further include a vacuuming device 200. The vacuuming device 200 includes at least a cavity 201 and a first valve 202. Dielectric Before the response test, the structure shown in FIG. 1 may be placed in the cavity 201 of the vacuuming device 200 for pumping to remove air bubbles that may exist between the first and second electrodes and the test sample.

The cavity 201 is adapted to receive the housing 101 described above. This accommodation means that the cavity 201 can accommodate the entirety of the housing 101. For example, the cavity 201 may be provided with an opening at the upper or side wall to allow the housing 101 to be integrally placed or removed. In order to withstand a higher degree of vacuum, the cavity 201 is preferably made of stainless steel.

The first valve 202 is disposed on the cavity 201. For example, it may be disposed on the top of the cavity 201 as shown in FIG. 2, or may be disposed on the sidewall or other position of the cavity 201. The first valve 202 is adapted to be externally connected to a vacuum pump for performing a vacuuming operation in the cavity 201.

Preferably, in the embodiment shown in FIG. 2, the vacuuming device 200 may further include a second valve 203 adapted to be coupled to a vacuum gauge 204.

One embodiment of a specific test procedure for an insulating dielectric response test system of the present invention is discussed in detail below in conjunction with FIGS. 1 and 2. The invention is not limited to the embodiments discussed below.

For example, assuming that the measurement object is a single-layer insulating paperboard without an oil gap, it is only necessary to place the paperboard 105 on the second electrode 104, and fix the cardboard with four Teflon pillars 106 to prevent the cardboard 105 from drifting everywhere, resulting in The contact area of the cardboard 105 and the first and second electrodes is changed, and then the nut 114 is adjusted to press the first electrode 103 against the test paperboard 105, and in order to make the cardboard 105 and the upper and lower electrodes in close contact, the larger quality copper cake is required. 110 is pressed on the first electrode 103.

During the placement of the cardboard 105, some bubbles are inevitably generated between the cardboard 105 and the two electrodes, and the dielectric parameters of the bubbles and the oil-paper insulation are not equal, so the dielectric test results are greatly affected, and each The generation of the secondary bubbles is random, resulting in poor repeatability of the experimental results. Therefore, before the test is performed, the entire structure shown in the test chart 1 is placed in the vacuuming device 200 shown in Fig. 2 for the degassing operation.

After the structure of Fig. 1 is placed in the cavity 201, the sealing plug 112 must first be removed, and then the entire cavity 201 is sealed to begin vacuuming. First, the

valves

202 and 203 are opened, and the valve 202 is connected to a vacuum pump (not shown) through a pipe. The valve 203 is connected to a vacuum pressure gauge 204 (negative pressure gauge), and the air pressure is observed. When the reading is close to, for example, -0.01 MPa, The valve 202 is closed first, then the vacuum pump is turned off, and the entire test system is allowed to stand, for example, for about 1 hour, so that the bubbles completely disappear.

After removing the air bubbles, open the valve 202 to ventilate for a period of time, so that the internal and external air pressures are consistent, then gently tap The lid of the vacuuming device 200 (disposed on the top or side wall of the cavity 201) is opened to quickly seal the sealing plug 112 to prevent intrusion of external moisture, and then the leads of the first and second electrodes are connected to the test instrument.

When wiring, the high voltage measuring line of the instrument is first connected to the first electrode 103 (high voltage electrode) through the terminal 109, and the measuring line is connected to the second electrode 104 through the

terminals

115, 118 of the corresponding measuring electrode and the terminal 116 (measurement) The electrode is connected to the protective electrode through the terminal 117 of the protective electrode and the terminal 116. At the same time, it should be noted that it is recommended to directly connect the cable of the test instrument to the test electrode terminal. Otherwise, if the general wiring or other wiring is introduced in the middle, the test is susceptible to external electromagnetic interference.

When simulating transformer oil-paper insulation, it is necessary to test oil-paper insulation samples with oil gaps. Therefore, when placing the sample, according to the scale on the Teflon pillar 106, the relative position of the cardboard 105 is adjusted by the nut 107 on the pillar 106, and then the relative position of the first electrode 103 is controlled by the nut 114, and the outlet is adjusted. The ratio of the size of the oil passage to the cardboard is required, and then the steps discussed above are repeated.

It is apparent to those skilled in the art that various modifications and variations can be made in the above-described embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, it is intended that the present invention cover the modifications and modifications of the invention

Claims

An insulating dielectric response test system, comprising:

case;

a holder disposed in the housing and fixed to a bottom of the housing;

a first electrode disposed in the housing;

a second electrode disposed on the support and located below the first electrode;

a sample to be tested, disposed between the first electrode and the second electrode;

a plurality of scaled positioning rods are vertically disposed at an edge of the support for fixing the sample to be tested, and each of the positioning screws is threaded with at least one pair of nuts, wherein the measured The sample is sandwiched between a pair of nuts therein;

The vacuuming device, wherein the vacuuming device further comprises: a cavity adapted to receive the housing and a first valve disposed on the cavity and adapted to externally connect a vacuum pump.
The insulating dielectric response test system according to claim 1, wherein the positioning rod and the support are made of polytetrafluoroethylene.
The insulating dielectric response test system of claim 1 wherein said vacuuming means further comprises a second valve adapted to connect to a vacuum gauge.
The insulating dielectric response test system of claim 1 wherein said top of said housing has an opening, wherein one end of a rod is coupled to said first electrode and said struts are One end extends through the opening to the outside of the housing and is adapted to connect a weight outside the housing.
The insulating dielectric response test system according to claim 4, wherein said weight is a copper cake having a screw hole at the center, and said other end of said strut has a matching with said screw hole Thread.
The insulating dielectric response test system of claim 4, wherein the struts are conductive rods that are in electrical contact with the first electrode at one end.
The insulating dielectric response test system according to claim 4, wherein said strut is provided with a pair of nuts, one of said pair of nuts being located outside said casing, said pair of nuts The other of the two is located in the housing, and the strut is provided with a corresponding thread structure to allow the first electrode and the sample to be tested to be adjusted by the cooperation of the pair of nuts and the thread structure The spacing between them.
The insulating dielectric response test system of claim 1 wherein said housing has a sealing aperture that cooperates with the sealing plug.
The insulating dielectric response test system of claim 1 further comprising a guard electrode disposed on said mount, wherein said guard electrode surrounds said second electrode and exposes said second electrode Upper surface.
The insulating dielectric response test system of claim 1 wherein the cavity is made of stainless steel.