High voltage test transformers will also fail in ordinary use, but small faults such as short circuit can be avoided. Now, as we introduce in detail the frequent failures and solutions of high voltage test transformers.
1, line cake bending deformation up and down. This kind of damage is due to the wire between two axial pads under the action of axial electromagnetic force, due to excessive bending moment permanent deformation, usually the deformation between two cakes is symmetric.
2, axial instability. This damage is mainly caused by the axial electromagnetic force caused by radial magnetic leakage, which leads to the axial deformation of the transformer winding.
3, winding or wire cake collapse. This damage is due to the wire under the action of axial force, mutual extrusion or impact, resulting in tilt deformation. If the original wire is slightly inclined, the axial force will increase the inclination and collapse in serious cases. The larger the ratio of wire height to width, the more likely it is to cause collapse. In addition to the axial component, there is also a radial component in the end leakage field. The synthetic electromagnetic force generated by the magnetic leakage in two directions causes the inner winding wire to turn inward and the outer winding to turn outward.
4. The windings are raised to support the platen. This kind of damage is often because the axial force is too large or the strength and stiffness of the end support parts are not enough or the assembly is defective.
5, radial instability. This damage is mainly caused by the radial electromagnetic force caused by the axial magnetic leakage, resulting in the radial deformation of the transformer winding.
6. Insulation damage is caused by elongation of outer winding wire. The radial electromagnetic force attempts to enlarge the diameter of the outer winding and causes permanent deformation when the tensile stress acting on the wire is too large. This kind of deformation is usually accompanied by wire insulation damage resulting in short circuit between turns, serious will cause the coil embedded, disorderly and collapse, or even fracture.
7, winding end overturn deformation. In addition to the axial component, there is also a radial component in the end leakage field. The synthetic electromagnetic force generated by the magnetic leakage in the two directions causes the winding wire to turn inward and the outer winding to turn outward.
8. The inner winding wire is bent or warped. The radial electromagnetic force makes the diameter of the inner winding smaller, and the bending is the result of the permanent deformation caused by excessive bending moment of the wire between the two supports (inner stays). If the binding of the core is sufficiently tight and the radial bracing of the winding is effectively supported, and the radial electric force is evenly distributed along the circumferential direction, the deformation is symmetric and the whole winding is a multilateral star shape. However, due to the deformation of the iron core under compression, the strut is not the same, the force along the circumference of the winding is not uniform, in fact, local instability often occurs to form warping deformation.
Xinshengneng Xiaobian summary: high voltage test transformer as a core part of the power system, simple troubleshooting and maintenance is a necessary common sense, I hope xiaobian today to share helpful, have any questions welcome to inquire.
