Dephasing self-coupling zigzag transformer

Abstract

The invention discloses a dephasing self-coupling zigzag transformer. The dephasing self-coupling zigzag transformer is connected with a transformer load and an arc-suppression-coil load. The dephasing self-coupling zigzag transformer comprises a three-phase high-voltage winding. Each phase of coil of the high-voltage winding comprises an upper coil and a lower coil. The upper coil and the lower coil have same number of turns. The upper coil sleeves an upper iron core of a three-phase iron core. The lower coil sleeves a lower iron core of the three-phase iron core. The upper coil is a main winding with a voltage-adjusting tap. The lower coil is a dephasing winding with a dephasing effect. The dephasing winding and the voltage-adjusting winding have a 60-degree phase relation on each phase.When zero sequence currents with a certain magnitude pass through the transformer, currents of the two single windings on a same steel iron core column are different in direction but same in magnitude, so that magnetic potentials generated by the zero sequence currents are opposite to be offset, and the zero-sequence impedance is low.

Description

technical field [0001] The invention relates to the field of transformers, in particular to a phase-shifting auto-coupling meander transformer. Background technique [0002] At present, with the diversification process of the rectification system, the rectification transformer, as the power supply part of the rectification system, also presents diversified characteristics. Since the rectifier winding current is non-sinusoidal and contains many high-order harmonics, in order to reduce the harmonic pollution to the grid and improve the power factor, the pulse number of the rectifier must be increased, which can be solved by phase shifting. The purpose of phase shifting is to make a phase shift between the voltages of the same-named terminal lines of the secondary winding of the rectifier transformer. [0003] The phase-shifting method is to use two windings connected by quantity and angle on the secondary side, which can double the pulse number of the rectifier electric furna...

AI Technical Summary

Problems solved by technology

[0006] During the operation of the phase-shifting auto-coupling transformer in the prior art, a certain magnitude of zero-sequence current will pass through, which will cause the following effects:

[0007] First, the impact on distribution transformers

[0008] (1) The unbalanced three-phase load will increase the loss of the transformer;

[0009] (2) Unbalanced three-phase load may cause serious consequences of burning the transformer;

[0010] (3) The unbalanced operation of the three-phase load will cause the zero-sequence current of the transformer to be too large, and the temperature rise of local metal parts will increase;

[0011] Second, the impact on high-voltage lines

[0012] (1) Increase the loss of high-voltage lines;

[0013] (2) Increase the number of high-voltage line trips and reduce the service life of switchgear;

[0014] 3. Impact on power distribution panel and low-voltage lines

[0015] (1) Unbalanced three-phase load will increase line loss;

[0016] (2) The unbalanced three-phase load may cause serious consequences of burning the line and burning the switchgear;

[0017] 4. Negative impact on power supply enterprises and users

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