On-load tap-changer

Abstract

The invention relates to an on-load tap changer for uninterrupted switching between winding taps of an adjustable transformer. Here, the general inventive concept consists in tapping the first winding of the first main current branch via a series circuit comprising a first mechanical changeover switch and a first switching mechanism, ie a vacuum switch tube or alternatively a semiconductor component Connected to the load lead, the second winding of the second main current branch is tapped in a similarly symmetrical manner via a second mechanical switch and a second switching mechanism, namely a second vacuum switch or alternatively A series circuit of grounded second semiconductor components is likewise connected to the load lead, a first auxiliary current branch with a loop-forming resistance branches off between the first winding tap and the first mechanical switch, By means of this resistance, an electrical connection to a second mechanical diverter switch of the second main current branch can be established, and between the second winding tap and the second mechanical diverter switch a branch with another A second auxiliary current branch forming a resistance of the loop, by means of which the further resistance can establish an electrical connection to the first mechanical switch of the first main current branch.

Description

technical field [0001] The invention relates to an on-load tap changer for uninterrupted switching between winding taps of a tapped transformer. Background technique [0002] For many years, tap-changers have been used in large numbers all over the world for the uninterrupted switching between different winding taps of tapped transformers. Such a tap changer usually comprises a selector for powerlessly selecting the corresponding winding tap of the tap changer to which it should be switched and an on-load switch for actually switching from the past winding tap to the new preselected winding tap. toggle switch. For this purpose, diverter switches usually have switching contacts and resistive contacts. The switch contacts are used here for the direct connection of the respective winding tap to the load lead, while the resistor contacts are used for short-term switching, ie bridging by means of one or more switching resistors. However, recent developments have deviated from ...

AI Technical Summary

Problems solved by technology

An asymmetrical circuit is generally easier to operate electrically, but has the disadvantage that its mechanical switching requires very costly structural solutions

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