Winding structure of high-power oil-immersed high-voltage variable frequency transformer

Abstract

The invention relates to a winding structure of a high-power oil-immersed type high voltage variable frequency transformer. The winding structure comprises three line side windings and six valve side windings, wherein the capacity and the voltage of the three line side windings are equal, the three line side windings are arranged in a split manner axially, the capacity and the output voltage of the six valve side windings are equal, every two valve side windings from a group, the three groups of the valve side windings are arranged in a split manner axially, each group of the valve side windings corresponds to one line side winding, and the valve side windings and the corresponding line side winding are arranged in a split manner radially. The winding structure of the high-power oil-immersed type high voltage variable frequency transformer has the advantages that the problem that ampere-turns in a transformer winding unit are unbalanced due to a failure bypass in a power unit is solved, loss of axial electrodynamic force and additional eddy current caused by the imbalanced ampere-turns is avoided, and the three-phase output power of the transformer is saved; at the same time, the height of center of gravity of the transformer is reduced, a frequency speed governing device can operate in a wider speed adjustable range safely and reliably for a long time, the operation energy consumption is reduced, and the winding structure is convenient to transport, mount and maintain.

Description

technical field [0001] The invention relates to a winding structure of a high-power oil-immersed high-voltage variable-frequency transformer. Background technique [0002] Chinese Patent Document No. CN203423055U discloses an oil-immersed rectifier transformer for high-voltage high-voltage frequency conversion, which consists of two 18-pulse rectifier transformer bodies, that is, the grid side of each body is divided into three windings with equal capacity, and the shaft On the valve side, there are 6 valve side windings with equal capacity and axial arrangement, and one network side winding corresponds to two valve side windings with the same phase shift angle, forming a winding group. [0003] The technical solution of this patent document is characterized by: when the frequency conversion device is in normal operation, the winding layout has different grid side and valve side windings with good impedance matching, easy to meet the system's requirements for short-circuit i...

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Problems solved by technology

[0004] The disadvantages of the technical solution of this patent document are: 1) when a certain power unit exits operation through bypass due to a fault, the secondary winding of the transformer supplying power for the power unit will be in an open circuit state

At this time, in the group where the secondary winding is located, one grid-side winding will operate for the other group of valve-side windings. In this operating state, due to the serious ampere-turn imbalance between the grid and valve-side windings , will produce a large radial magnetic flux leakage component, which will interact with the current in the winding, and will generate a large axial force on the network and valve side windings. Under the joint action of the short-circuit force generated by commutation with the rectifier element It is easy to damage the winding insulation and affect the long-term safe operation of the product; 2) The corresponding part of the grid-side winding corresponding to the valve-side winding running in an open circuit will generate a large eddy current loss, causing local overheating and accelerating the aging of the winding insulation, which also affects the long-term performance of the product. Safe operation; 3) When the winding on the valve side adopts the axial arrangement, the installation size in the height direction of the whole machine is relatively large, and the center of gravity is high, which is inconvenient for transportation and on-site installation and maintenance

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