Delta connection structure for secondary side of high-current pulse short-circuit dry type transformer

Abstract

The invention discloses a delta connection structure for a secondary side of a high-current pulse short-circuit dry type transformer. According to the structure, respective delta connection on the upper end part and the lower end part of an axial double split transformer is cancelled; the same terminals of an upper winding and a lower winding of the secondary side of each phase are directly connected in parallel; delta connection of the secondary side of the transformer is realized at a middle point of a parallel connection bar; and a wire lead-out end of the secondary side of the transformer is led out from the middle point of a delta connection bar. According to the structure, the same phase invert parallel connection characteristic is fully utilized, and the impedance of the parallel bar is effectively reduced; the wire is led out of the middle part of the delta connection bar, and the phenomenon of unbalanced impedance caused by different lengths of an angle joint bar is obviously improved; and meanwhile, the impedance of the delta connection copper bar and a load connection bar is effectively reduced. The structure has a great application value in the application field of the dry type transformer with large capacity, low-voltage and high-current secondary side and low short-circuit impedance; and the connection structure is not shown in the application of other transformer products yet.

Description

technical field [0001] The invention relates to the technical field of power transmission and transformation applications in electric power systems, in particular to a secondary triangle connection structure for high-current pulse short-circuit dry-type transformers. Background technique [0002] The transformers used in the dynamic stability test of electrical equipment all have common characteristics: the secondary side voltage regulator is not high, the secondary side output current is huge, the short-circuit impedance is small, the overload multiple is high, the resistance to electrodynamic shock is strong, and the pulse (intermittent) work system. Dry-type transformers have the advantages of high structural mechanical strength, strong resistance to electrodynamic shocks, cleaning and easy maintenance, etc., and are well applied in short-circuit impact tests at voltage levels of 35kV and below. [0003] Dry-type transformers are difficult to break through the limitatio...

AI Technical Summary

Problems solved by technology

If the connection method of the secondary side copper bars is improperly selected, the overall short-circuit impedance of the transformer will be significantly increased, and the phases will be seriously unbalanced

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