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A Realization Method of Low Frequency Heating for Large Power Transformer

A power transformer and low-frequency heating technology, which is applied in the direction of ohmic resistance heating, electric heating devices, electrical components, etc., can solve the problems of difficulty in field use, large heating device, and difficult field application, etc., and achieve simple main circuit, light weight, and device volume small effect

Active Publication Date: 2015-11-11
STATE GRID CORP OF CHINA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current "short-circuit method" mainly uses power frequency. The power supply must not only provide active power for winding heating, but also provide reactive power consumed by the transformer. The required power supply capacity is large and it is difficult to use on site; The device is huge, inconvenient to move, and difficult to apply on site

Method used

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  • A Realization Method of Low Frequency Heating for Large Power Transformer
  • A Realization Method of Low Frequency Heating for Large Power Transformer
  • A Realization Method of Low Frequency Heating for Large Power Transformer

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Embodiment Construction

[0036] Below in conjunction with embodiment and accompanying drawing, the present invention is further described: as figure 1 As shown in , the low-frequency heating device of the large-scale power transformer includes a phase-shifting transformer 2 and an AC-AC frequency conversion device 3, the input end of the phase-shifting transformer 2 is connected to the three-phase AC power supply 1, and the output end of the phase-shifting transformer 2 is connected to The input end of the AC-AC frequency conversion device 3, the output end of the AC-AC frequency conversion device 3 is connected to one side port of the heated transformer 4, and the other side port of the heated transformer 4 is short-circuited; The AC frequency conversion device 3 includes two three-phase rectifier bridges connected in antiparallel, and the two three-phase rectifier bridges connected in antiparallel respectively output positive waves and negative waves to the heated transformer. On the basis of the ab...

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Abstract

The invention discloses a large power transformer low-frequency heating device and an achieving method. The device comprises a phase-shifting transformer, an AC-AC frequency conversion device and a heated transformer, wherein the phase-shifting transformer, the AC-AC frequency conversion device and the heated transformer are sequentially connected. The port of the other side of the heated transformer is in a short circuit. The AC-AC frequency conversion device comprises two three-phase rectifier bridges which are connected in parallel in opposite directions. The power and the transformation ratio of phase-shifting transformation and the output voltage, power and frequency of the frequency conversion device are calculated according to the parameters of the heated transformer, and the heating effect of the transformer is controlled by adjusting the frequency value. The two rectifier bridges are directly connected in parallel in opposite directions, frequency conversion is achieved by utilizing a thyristor in a natural current conversion mode, working is stable and reliable, a DC link is removed, a main circuit is simple, and the frequency conversion efficiency is high. A frequency conversion power supply with the two rectifier bridges directly connected in parallel in opposite directions is utilized, the large power transformer low-frequency heating device has the more obvious advantage in on-spot short circuit heating of a large power transformer.

Description

technical field [0001] The invention relates to a test method for a large-scale power transformer, in particular to a method for realizing low-frequency heating of a large-scale power transformer. The large transformer mentioned in the present invention refers to a power transformer with a voltage level of 500kV and above, including a converter transformer. Background technique [0002] Large-scale power transformers are bulky and heavy, and the transportation of finished products is very difficult. Therefore, the construction mode of dismantling, transportation and on-site assembly tends to be adopted in power engineering. During the on-site assembly of the transformer, the insulating parts may be exposed to moisture in the air. Therefore, after the installation is completed and before being put into operation, the transformer needs to be heated to discharge the internal moisture, improve the dry strength of the insulating parts, and then improve the electrical strength. ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H05B3/00
Inventor 汪发明汪涛金涛谢齐家高得力贺家慧刘建军
Owner STATE GRID CORP OF CHINA
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