On-load tap-changer for high-voltage power transmission transformer and control method of on-load tap-changer

Abstract

The invention provides an on-load tap-changer for a high-voltage power transmission transformer and a control method of the on-load tap-changer. The on-load tap-changer comprises a tap selector and apower electronic change-over switch; the power electronic change-over switch comprises a mechanical switch assembly, a power electronic switch assembly and an insulating sleeve; the mechanical switchassembly is connected with a winding tap of the high-voltage power transmission transformer through a tapping selector, the tapping selector and the mechanical switch assembly are both located in thehigh-voltage power transmission transformer, the power electronic switch assembly (4) is located outside the high-voltage power transmission transformer, the mechanical switch assembly can achieve non-arc switching-on and switching-off, and safety is high. The power electronic switch assembly does not need to bear voltage stress for a long time in the steady-state operation process, can bear lightning impulse and is not prone to breakdown and failure. By adopting the full-control power device, the time delay of a thyristor caused by current zero-crossing turn-off can be shortened, the switching speed is improved, the heating of a current-limiting resistor is reduced, and the service life of the on-load tap-changer is prolonged.

Description

technical field [0001] The invention relates to the technical field of transformers, in particular to an on-load tap changer for high-voltage transmission transformers and a control method thereof. Background technique [0002] The on load tap changer (OLTC) is the core component of the power transformer to complete the voltage regulation. The power transformer on-load voltage regulation technology is an important means of stabilizing the voltage. Switch the power transformer from one tap to another, and achieve the purpose of voltage regulation by adjusting the effective number of turns of the transformer winding. At present, more than 90% of domestic power transformers from 10 to 500kV are equipped with on-load tap-changers, and the on-load tap-changers used are all mechanical on-load tap-changers. Due to the large number of moving parts in the mechanical on-load tap-changer, the switching time is long. Once the timing error of adjacent mechanical switching exceeds the pr...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the disadvantages of poor security in the above-mentioned prior art, the present invention provides an on-load tap changer for high-voltage transmission transformers, including a tap selector (1) and a power electronic changeover switch (2); the power electronic The diverter switch (2) includes a mechanical switch assembly (3), a power electronic switch assembly (4) and an insulating bushing;

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