Neutral formed transformer with boosting function

Abstract

The invention discloses a neutral formed transformer with a boosting function for solving the technical problem that the existing neutral formed transformer is changeless in ratio of transformation. The neutral formed transformer comprises a first winding, a second winding, a third winding, a fourth winding, a fifth winding, a sixth winding, a seventh winding, an eighth winding, a ninth winding and a three-phase core. All the windings are strictly identical in winding direction, the first winding, the fourth winding and the seventh winding are wound on a first core limb, the second winding, the fifth winding and the eighth winding are wound on a second core limb, and the third, sixth and ninth windings are wound on a third core limb. Since the method that the two windings with the turns ratio designed optionally replace one winding in the background art is adopted, primary-secondary side transformation ratio of the transformer is no longer 1:1 only, the transformation ratio can be designed optionally within a certain range, and flexibility in application is improved; meanwhile, part of load current flows through the inside of the transformer rather than zero-sequence current simply, and utilization rate of the core of the transformer is increased.

Description

Technical field [0001] The invention relates to a midpoint forming transformer, in particular to a midpoint forming transformer with a boost function. Background technique [0002] Reference Figure 4 . The document "Analysis of midpoint forming transformer, Journal of Nanjing University of Aeronautics and Astronautics, 1993, 25(03): pp.341-350" discloses a transformer used to form a three-phase three-wire system into a three-phase four-wire system- The point forms a transformer (NFT). The midpoint forming transformer includes a three-phase iron core and six windings with the same number of turns from No. 1 to No. 6. The midpoint forms the windings of the transformer with a zigzag connection. The purpose is that when the zero-sequence current passes through these windings, the zero-sequence magnetic flux generated by the windings on the same iron core column mostly cancel each other, so the zero-sequence impedance is greatly reduced, thereby reducing The zero sequence potential...

AI Technical Summary

Problems solved by technology

[0004] 1. The transformation ratio of the primary and secondary sides of the transformer formed by the midpoint can only be 1:1, so the transformer cannot change the amplitude of the input and output voltages.

[0005] 2. The midpoint forms the internal winding of the transformer and only flows through the zero-sequence current, which has no effect when the three-phase load is balanced, resulting in a low utilization rate of the transformer core

[0006] Due to the several shortcomings of the transformer formed by the midpoint, the scope of use of the transformer is limited, and the application in recent years is relatively rare.

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