Induction withstand voltage is different from power frequency withstand voltage. Power frequency withstand voltage is the application of processing frequency high voltage on the primary side, while induction withstand voltage is the application of a frequency doubling voltage that is a certain multiple higher than the rated voltage on the low-voltage side of a transformer or transformer. The required test voltage is obtained on the high-voltage winding by the electromagnetic induction of the transformer itself to test the longitudinal insulation performance of the transformer, especially for transformers with graded insulation of the neutral point, Due to the inability to use external high voltage for power frequency AC withstand voltage testing, both the main insulation and longitudinal insulation are evaluated through induction withstand voltage testing. The measurement of induction withstand voltage should be carried out using an electronic multi frequency generator that meets national standards or a simplified version of a triple frequency power generator.
The difference between induced voltage withstand and power frequency voltage withstand
The power frequency AC withstand voltage test only checks the electrical strength of the main insulation of the winding, that is, the insulation between the high voltage, medium voltage, and low voltage windings and the grounding parts of the oil tank, iron core, shell, etc., while the induced withstand voltage test is the insulation performance test that checks the longitudinal insulation between turns, layers, and breaks. They are complementary but cannot replace each other.