What is the transformer winding deformation test?
Transformer winding deformation testing is a detection method that examines changes in electrical parameters, such as inductance, capacitance, and impedance of the winding, to determine whether the winding has undergone axial/radial displacement, distortion, or bulging. These deformations are mostly caused by short-circuit impacts, transportation vibrations, and overheating aging, and they will directly affect the insulation performance and operational stability of the transformer.
Is the SFRA analysis method the primary method for conducting transformer winding deformation tests?
Transformer winding deformation testing is a detection method that examines changes in electrical parameters, such as inductance, capacitance, and impedance of the winding, to determine whether the winding has undergone axial/radial displacement, distortion, or bulging. The frequency response analysis method (FRA)
Principle: Inject a wide-band signal into the winding, collect the amplitude-frequency/phase-frequency response curves of the winding, and compare them with the original curve or the curve of the same type of transformer. Through similarity, the degree of deformation can be determined.
Advantages: High sensitivity, capable of detecting micrometer-level deformation, suitable for transformers of all voltage levels.
Judgment criteria: According to the DL/T 911-2016 standard, use correlation coefficients, frequency deviations, etc., to quantify the curve differences. These deformations are mostly caused by short-circuit impacts, transportation vibrations, and overheating aging, and will directly affect the insulation performance and operational stability of the transformer.