On-load tapping switch of tandem type composite change-over switch transformer

Abstract

The invention relates to the field of transformers and discloses an on-load tapping switch of a tandem type composite change-over switch transformer. The on-load tapping switch comprises odd taps, even taps, an outgoing terminal, a first composite switch, a second composite switch, a first tapping selector and a second tapping selector, wherein a plurality of fixed contacts of the first tapping selector are respectively connected with the odd taps; a moving contact of the first tapping selector is connected with one end of the first composite switch; a plurality of fixed contacts of the second tapping selector are respectively connected with the even taps; a moving contact of the second tapping selector is connected with one end of the second composite switch; and the other end of the first composite switch and the other end of the second composite switch are connected with the outgoing terminal. In the on-load tapping switch, the composite switches are used and the trigger time sequence of the composite switches is controlled, so that the non-arc switching of the on-load tapping switch can be realized; and the on-load tapping switch is simple in structure and reliable in work.

Description

technical field [0001] The invention relates to the field of transformers, in particular to an on-load tap changer for a series compound changeover switch transformer. Background technique [0002] In the prior art, due to changes in the primary side voltage (grid voltage) and load size and nature of the operating transmission and distribution transformer, the secondary side voltage may have a large change. In order to maintain the load voltage within the specified range (±5% UN) and ensure the normal needs of electrical equipment, the voltage of the transmission and distribution transformer must be adjusted. [0003] The basic principle of transformer on-load voltage regulation is to draw several taps from the coil on one side of the transformer (usually the high-voltage side), and switch from one tap to Another tap is used to change the effective number of turns to adjust the voltage. The on-load tap changer is composed of two parts, one part is the transformer body, whi...

AI Technical Summary

Problems solved by technology

Although compared with the electromechanical hybrid switch, the drag mechanism is removed, but the electrical life of the vacuum switch is still limited, which limits the application of the vacuum tap changer

[0007] Some schemes propose to use electronic switches such as IGBT or thyristors instead of transition resistors on the basis of vacuum switches to realize arc-free switching of switch taps. The steady-state load current is borne by the vacuum switch branch, while the off-state tap branch is borne by the vacuum switch. The switch bears the off-state voltage. The problem with this type of scheme is that it is difficult to ensure arc-free transition when switching from the vacuum switch branch to the electronic switch branch.

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