During the operation of high-voltage electrical equipment such as transformers, oil circuit breakers, oil-filled cables, power capacitors and oil bushings, the performance of insulating oil will gradually deteriorate due to the action of oxygen, high temperature, high humidity, sunlight, strong electric field and impurities. , so that it cannot fully exert its insulating effect, so the insulating oil must be tested regularly to identify whether its performance has deteriorated. The quality of insulating oil is closely related to breakdown voltage.
The breakdown voltage is a measure of the ability of the medium to withstand voltage without being damaged. It is one of the main indicators to test the performance of transformer oil. Dry and clean oil has a very high breakdown voltage value. The main factors affecting the breakdown voltage of transformer oil are moisture, impurities, temperature, etc. The relationship between temperature and breakdown voltage is more complicated. For dry, impurity-free oil, the breakdown voltage is maintained by the non-dissociation of the neutral particles of the oil. of.
But when the oil contains free water, dissolved water or solid pollutants, because these impurities have higher conductivity and dielectric constant than the oil itself, they will form a conductive bridge under the action of the electric field and reduce the breakdown voltage of the oil . The insulating oil dielectric strength tester can judge whether there is moisture, impurities and conductive particles in the oil, but it cannot judge whether there is acid or sludge in the oil.
Generally, the breakdown voltage of transformer oil can reach 70KV before being degassed by vacuum filtration and added to the transformer. Insulating oil is an important dielectric material in electrical and industrial production. It is widely used in transformers and other electrical and electrical equipment for cooling and insulation.