Autotransformer and test connecting method thereof

Abstract

The invention relates to an autotransformer and a test connecting method thereof. The autotransformer is of a three-phase five-column type iron core structure, the autotransformer just contains a high-tension coil and a low-tension coil, the connecting type of the autotransformer is YNa0, an on-load voltage regulation manner is adopted at a high-tension side, and the coil arrangement manner comprises an iron core, a common coil, a voltage regulating coil and a series coil. The method comprises the following steps: additionally setting an intermediate transformer for testing in a star-angle type connecting type, and requiring the rated voltage of a star-like coil of the intermediate transformer for testing to be higher than or equal to that of the low-tension coil of the autotransformer; and enabling the low-tension coil of the autotransformer to be connected with the star-like coil of the star-angle type intermediate transformer for testing. Due to the fact that an angle joint coil is not arranged, the manufacturing cost of the transformer and the operating cost of a power grid are reduced, the installation occupied area of the transformer is reduced, and the operating trouble occurrence rate of the power grid is reduced.

Description

technical field [0001] The invention relates to a transformer manufacturing technology, in particular to an autotransformer and a test wiring method thereof. Background technique [0002] At present, the three-phase autotransformers in the transformer products of power equipment all include three coils, that is, the structure of YNa0d1 or YNa0d11. Among them, the coils on the primary side and the secondary side are used to transmit electric energy, and the balance coil (delta connection coil) plays the role of balancing the zero-sequence magnetic flux, avoiding the problem of third or higher harmonics, especially for large-capacity three-phase five-column The transformer of the type structure, the balanced coil (delta coil) avoids the problems of voltage imbalance between three phases and neutral point drift. Therefore, the existence of the delta coil has a great effect on the three-phase autotransformer. However, if the delta-connected coil does not bear any load in the p...

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Problems solved by technology

However, if the delta-connected coil does not bear any load in the power grid, the existence of the delta-connected coil will undoubtedly increase the manufacturing cost of the transformer, increase the operation and maintenance costs of the power grid equipment, and also increase the failure rate of the power grid. The design and manufacture of transformers and power stations are more complex

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