What is the purpose of transformer turns ratio test?

The transformer turns ratio test is used to determine the number of turns in one winding of a transformer in relation to the number of turns in the other windings of the same phase of the transformer. The transformer polarity test determines the vectoral relationships of the various transformer windings.

Why do we need to test turn ratio of transformer?

For example, in a power system, two transformers are usually operated in parallel, and the two transformers are required to have the same phase, and the phase difference between the two transformers cannot exceed 0.5%, otherwise, a large circulation will occur between the two transformers, and the loss of the transformer will increase, which will easily lead to faults, such as winding short circuit or open circuit, winding breakdown or burning, and winding deformation. These faults will affect the reliability of the transformer windings. Deterioration of transformer ratio parameters can reflect some transformer faults. Transformer transformer ratio test can detect winding interturn turn-to-turn short circuit, winding open circuit, winding breakdown and burn and other faults, and the method is simple, so the transformer will appear before operation or appear The transformer ratio needs to be checked after the fault to determine if the transformer can work normally.