Step-up transformer with dual-body structure for ultra-high-voltage generator

Abstract

The invention relates to a step-up transformer with a dual-body structure for an ultra-high-voltage generator. The transformer comprises a main body and a voltage regulating body which are arranged in the same oil tank of the transformer, wherein the iron core of the voltage regulating body is of a double-core-column structure; a first exciting coil and a first voltage regulating coil are sheathed on one core column; a second exciting coil and a second voltage regulating coil are sheathed on the other core column; the first exciting coil and the second exciting coil are connected in parallel to form an exciting coil which is in parallel connection with a low-voltage coil in the main body and is led out. According to the invention, a branching section of a high-voltage coil is not used, a voltage-regulating coil is arranged separately and is arranged on the other body; based on low-voltage exciting, the transformer does not regulates voltage in rated branching operation and regulates voltage only in the limit branching operation, therefore the electric potential distribution of the coil is improved, and the short-circuit resistant capability of the transformer is improved.

Description

technical field [0001] The invention relates to the technical field of transformer manufacturing, in particular to a double-bodied UHV generator step-up transformer. Background technique [0002] At present, there is no 1000kV single-phase non-excitation large-capacity generator step-up transformer in operation in the world, but for 500kV and 750kV generator transformers, high-voltage coils with tap sections are usually used for voltage regulation. The UHV non-excitation generator step-up transformer also adopts this method for voltage regulation, which has the following disadvantages: [0003] (1) Due to the high voltage, the number of turns of the high-voltage coil is large, and the ampere-turns of the tapping section are very unbalanced, thereby reducing the short-circuit resistance of the transformer; [0004] (2) The generator transformer operates under the rated working conditions most of the time, and the transformer also has half voltage regulation when operating un...

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Problems solved by technology

[0003] (1) Due to the high voltage and the large number of turns of the high-voltage coil, the ampere-turns of the tapping section are very unbalanced, thereby reducing the short-circuit resistance of the transformer;

[0004] (2) The generator transformer operates under the rated working conditions most of the time, and the transformer also has half voltage regulation when operating under the rated tap, which increases the load loss during the rated tap;

[0005] (3) This structure is relatively complicated, which is not conducive to the safe and reliable operation of the transformer;

[0006] (4) The height of the coil is increased, thereby increasing the transportation height of the transformer and increasing the transportation cost

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