Transformer winding deformation tester adopts the internal fault frequency response analysis (FRA) method which is being developed and perfected by developed countries in the world according to the measurement of the characteristic parameters of the internal winding of the transformer, and can accurately judge the internal fault of the transformer. By detecting the amplitude-frequency response characteristics of each winding of the transformer and comparing the detection results at all levels, the possible deformation of the transformer windings can be judged according to the degree of change in the amplitude-frequency response characteristics.
1.Conventional method Due to its low sensitivity, it is difficult to diagnose transformer winding deformation.
2. Capacitance method For example, when measuring the dielectric loss of transformer windings and bushings with a bridge, the concentrated capacitance CL of the low-voltage winding to the ground, the capacitance CHL between the high and low voltage windings, and the capacitance ch of the high-voltage winding to the ground can be measured. and calculated.
3. Low-voltage impedance method By measuring the impedance or leakage reactance of the transformer winding at 50Hz, it can be judged whether the transformer winding has deformation endangering the operation, such as inter-turn short circuit, open circuit, coil displacement, etc.
4. Frequency response method Input the scanning voltage signal vs (sine wave voltage signals of different frequencies in turn) at one end of the winding, and at the same time record the equipment by digitally detecting the voltage signals VI(n) and VO(n) at different scanning frequencies at both ends of the winding , so as to obtain the transfer function H(n) of the transformer winding under test.