High current shorting device and arc furnace transformer test assembly

Abstract

The present invention provides a high current short-circuit device, comprising: a frame; a three-phase connecting copper bar fixed on one side of the frame, wherein the three-phase connecting copper bars are insulated from each other by a first insulating plate; and a short-circuit assembly arranged on the other side of the frame, the short-circuit assembly comprising a short-circuit tripod and three-phase contacts respectively arranged at the vertices of the short-circuit tripod, the three-phase contacts respectively being conductively connected to each of the three-phase connecting copper bars via a connecting pipe, wherein at least two of the three-phase contacts are disconnectable contacts, wherein the disconnectable contacts comprise a first contact piece and a second contact piece, the first contact piece being fixed on the short-circuit tripod, and the second contact piece being in contact with or disconnected from the first contact piece under the drive of a hand wheel arranged on the frame. In addition, the present invention also provides an arc furnace transformer test assembly.

Description

Technical Field

[0001] The invention relates to the field of transformer testing, and in particular to a high-current short-circuit device and an arc furnace transformer testing assembly using the high-current short-circuit device. Background Art

[0002] For arc furnace transformers, the voltage on the low voltage side is generally low. However, when the transformer capacity is large, the low voltage current can reach tens of thousands to hundreds of thousands of amperes. During the temperature rise, load loss and other tests of the arc furnace transformer, all the outgoing bushings on the low voltage side need to be short-circuited. In addition, after the temperature rise test is completed, the three-phase short circuit needs to be quickly separated in order to measure the three-phase thermal resistance after the test. Therefore, it is necessary to develop a special short-circuit device on the low voltage side that can meet the requirements of large current flow and quickly separate the three-phase short circuit after the test is completed, so as to meet the above test requirements. Summary of the invention

[0003] In view of the above problems in the prior art, the present invention designs a large current short-circuit device and an arc furnace transformer test assembly thereof. The large current short-circuit device can be used for temperature rise test, load loss test and short circuit impedance test of arc furnace transformer, and can also be used for electric furnace transformer and rectifier transformer with tubular bushing and flat bushing on the low voltage side, so it has stronger versatility. After the temperature rise test, the large current short-circuit device can quickly separate the three-phase short circuit, so that the thermal resistance measurement is more accurate. In addition, during the test process, the device can pass coolant to avoid overheating of the device during the temperature rise test.

[0004] According to one aspect of the present invention, there is provided a high current short-circuiting device, comprising:

[0005] frame;

[0006] A three-phase connecting copper bar is fixed to one side of the frame, wherein the three-phase connecting copper bars are insulated from each other by a first insulating plate; and

[0007] A short-circuit assembly is arranged on the other side of the frame, and the short-circuit assembly includes a short-circuit tripod and three-phase contacts respectively arranged at each vertex of the short-circuit tripod, and the three-phase contacts are respectively conductively connected to each of the three-phase connecting copper bars via a connecting pipe.

[0008] Wherein, at least two of the three-phase contactors are disconnectable contactors,

[0009] The disconnectable contact head comprises a first contact piece and a second contact piece, wherein the first contact piece is fixed on the short-circuit tripod, and the second contact piece contacts or disconnects with the first contact piece under the drive of a hand wheel arranged on the frame.

[0010] According to one embodiment, in the above-mentioned high-current short-circuit device, the three-phase connecting copper busbar is a hollow copper plate, the connecting pipe is a hollow copper pipe, and the short-circuit tripod is made of a non-magnetic rectangular steel pipe.

[0011] According to one embodiment, in the above-mentioned high-current short-circuiting device, at least one coolant connector is provided on one or more of the three-phase connecting copper busbar, the connecting pipe and the short-circuiting tripod to allow the introduction and / or extraction of coolant.

[0012] According to one embodiment, in the above-mentioned high-current short-circuit device, the three-phase connecting copper bar and the frame are insulated from each other by a second insulating plate.

[0013] According to one embodiment, in the above-mentioned high-current short-circuit device, the short-circuit tripod and the frame are insulated from each other by a third insulating plate.

[0014] According to one embodiment, in the above-mentioned large current short-circuit device, the first, second and third insulating plates are all phenolic resin plates.

[0015] According to one embodiment, in the above-mentioned high-current short-circuit device, steering rollers are provided at four corners of the bottom of the frame.

[0016] According to one embodiment, in the above-mentioned high current short-circuit device, a track is arranged on the frame, and the second contact piece is arranged on the track.

[0017] Wherein, when the hand wheel is rotated, the second contact piece moves along the track.

[0018] According to another aspect of the present invention, an arc furnace transformer test assembly is provided, comprising an arc furnace transformer and a high current short-circuiting device as discussed above, wherein the low voltage side bushing of the arc furnace transformer is suitable for being connected to the three-phase connecting copper bars respectively.

[0019] According to one embodiment, in the above-mentioned arc furnace transformer test assembly, the low voltage current on the low voltage side of the arc furnace transformer is between 10,000 amperes and 200,000 amperes.

[0020] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present invention and together with the specification serve to explain the principles of the present invention. In the accompanying drawings:

[0022] Figure 1A schematic diagram of an embodiment of a high current short-circuiting device according to the present invention is shown.

[0023] Description of reference numerals:

[0024] 10 racks

[0025] 20 Three-phase copper busbar

[0026] 30 Shorting components

[0027] 31 Short-circuit tripod

[0028] 32 three-phase contactor

[0029] 33 Connecting pipe

[0030] 321 First contact piece

[0031] 322 Second contact piece

[0032] 41 first insulating plate

[0033] 42 Second insulation board

[0034] 43 Third connecting plate

[0035] 50 tracks

[0036] 60 Handwheel

[0037] 70 Coolant connector

[0038] 80 Steering roller DETAILED DESCRIPTION

[0039] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used in all drawings to represent the same or similar parts. In addition, although the terms used in the present invention are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present invention may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description herein. In addition, it is required to understand the present invention not only by the actual terms used, but also by the meaning implied by each term.

[0040] refer to Figure 1 The basic principles and preferred embodiments of the present invention are discussed in more detail. Figure 1 In the illustrated embodiment, the high-current short-circuit device according to the present invention mainly includes a frame 10 , a three-phase connecting copper bus 20 and a short-circuit assembly 30 .

[0041] The three-phase copper connection bar 20 is fixed to one side of the rack 10. The three-phase copper connection bar 20 is insulated from each other by a first insulating plate 41. In addition, the three-phase copper connection bar 20 and the rack 10 can be insulated from each other by a second insulating plate 42.

[0042] The short-circuit assembly 30 is disposed on the other side of the frame 10, opposite to the above-mentioned three-phase connection copper bar 20. The short-circuit assembly 30 includes a short-circuit tripod 31 and three-phase contacts 32 respectively disposed at each vertex of the short-circuit tripod 31. The three-phase contacts 32 are respectively conductively connected to each of the three-phase connection copper bars 20 via a connecting pipe 33. In addition, the short-circuit tripod 31 and the frame 10 are insulated from each other by a third insulating plate 43.

[0043] Specifically, at least two of the three-phase contacts 32 are disconnectable contacts. Figure 1 In the illustrated embodiment, the two contact heads 32 located at the bottom of the short-circuit tripod 31 are the above-mentioned disconnectable contact heads. The disconnectable contact head includes a first contact piece 321 and a second contact piece 322. The first contact piece 321 is fixed to the short-circuit tripod 31, and the second contact piece 322 is driven by a hand wheel 60 provided on the frame 10 to contact or disconnect with the first contact piece 321.

[0044] According to a preferred embodiment, Figure 1 As shown, a track 50 is further provided on the frame 10, and the second contact piece 322 is provided on the track 50. When the hand wheel 60 is turned, the second contact piece 322 moves along the track 50 to achieve contact and / or disconnection with the first contact piece 321.

[0045] On the other hand, the three-phase copper busbar 20 can be made of a hollow copper plate, the connecting pipe 33 can be made of a hollow copper pipe, and the shorting tripod 31 can be made of a non-magnetic rectangular steel pipe. In this way, these components all have a hollow structure, and at least one coolant connector 70 can be provided on one or more of the three-phase copper busbar 20, the connecting pipe 33 and the shorting tripod 31. Figure 1 During the test, coolant may be passed through the above components to remove the heat generated by the test device during the temperature rise test.

[0046] The first insulating plate 41 , the second insulating plate 42 , and the third insulating plate 43 may all be made of phenolic resin plates.

[0047] In addition, Figure 1 In the illustrated embodiment, steering rollers 80 are respectively provided at the four corners of the bottom of the frame 10 to facilitate the movement of the device.

[0048] By connecting the above-mentioned high-current short-circuit device to an arc furnace transformer (not shown), an arc furnace transformer test assembly is formed. The low-voltage current on the low-voltage side of the arc furnace transformer is between 10,000 amperes and 200,000 amperes. The low-voltage side bushing of the arc furnace transformer is respectively connected to the three-phase connecting copper bar 20 of the high-current short-circuit device. When conducting tests such as temperature rise and load loss of the arc furnace transformer, the first contact piece 321 and the second contact piece 322 of the disconnectable contact head are kept in contact. After completing the above test, there is no need to remove the connection between the arc furnace transformer and the three-phase connecting copper bar 20. The first contact piece 321 and the second contact piece 322 can be quickly disconnected within 1 minute by turning the hand wheel 60 to separate the three-phase short circuit and measure the low-voltage winding thermal resistance.

[0049] In summary, the high-current short-circuit device of the present invention has strong versatility and can quickly separate the three-phase short circuit, making the thermal resistance measurement more accurate. And the entire device can pass cooling water to avoid overheating of the device during the temperature rise test. This technical solution realizes the independent development of the test device for the electric furnace transformer. The products tested using this device have passed the final test, and its performance in the temperature rise test, load loss test and short-circuit impedance test meets the expected requirements.

[0050] It will be apparent to those skilled in the art that various modifications and variations may be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention covers modifications and variations of the present invention that fall within the scope of the appended claims and their equivalent technical solutions.

Claims

1. A high current short-circuit device, characterized in that: include: Frame (10); A three-phase connecting copper bar (20) is fixed to one side of the frame, wherein the three-phase connecting copper bars are insulated from each other by a first insulating plate (41); as well as A short-circuit assembly (30) is arranged on the other side of the frame, the short-circuit assembly comprises a short-circuit tripod (31) and three-phase contacts (32) respectively arranged at the vertices of the short-circuit tripod, the three-phase contacts respectively being electrically connected to each of the three-phase connecting copper bars via a connecting pipe, Wherein, at least two of the three-phase contactors are disconnectable contactors, The disconnectable contact head comprises a first contact piece (321) and a second contact piece (322), wherein the first contact piece is fixed on the short-circuit tripod, and the second contact piece contacts or disconnects with the first contact piece under the drive of a hand wheel (60) arranged on the frame.

2. The high current short-circuiting device according to claim 1, characterized in that: The three-phase connecting copper bar (20) is a hollow copper plate, the connecting pipe (33) is a hollow copper pipe, and the short-circuit tripod (31) is made of a non-magnetic rectangular steel pipe.

3. The high current short-circuit device according to claim 2, characterized in that: At least one coolant connector (70) is provided on one or more of the three-phase connecting copper busbar (20), the connecting pipe (33) and the short-circuiting tripod (31) to allow the introduction and / or extraction of coolant.

4. The high current short-circuit device according to claim 1, characterized in that: The three-phase connecting copper bar (20) and the frame (10) are insulated from each other by a second insulating plate (42).

5. The high current short-circuit device according to claim 4, characterized in that: The short-circuit tripod (31) and the frame (10) are insulated from each other via a third insulating plate (43).

6. The high current short-circuiting device according to claim 5, characterized in that: The first, second and third insulating plates are all phenolic resin plates.

7. The high current short-circuit device according to claim 1, characterized in that: Steering rollers (80) are arranged at the four corners of the bottom of the frame (10).

8. The high current short-circuit device according to claim 1, characterized in that: A track (50) is arranged on the frame (10), and the second contact piece (322) is arranged on the track. When the hand wheel (60) is rotated, the second contact piece moves along the track.

9. An arc furnace transformer test assembly, characterized in that: It comprises an arc furnace transformer and a high current short-circuiting device as claimed in any one of claims 1 to 8, wherein the low voltage side bushing of the arc furnace transformer is suitable for being connected to the three-phase connecting copper busbars (20) respectively.

10. The arc furnace transformer test assembly according to claim 9, characterized in that: The low voltage current on the low voltage side of the arc furnace transformer is between 10,000 amperes and 200,000 amperes.

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