Allowable Insulation Distance Of Dry Resin Type Transformer
The price of insulation is a significant part of the price of a transformer. In 110 and 220 kV high-voltage transformers, the price of insulation can reach 18-25% of the price of the entire transformer. When the insulation gap, material and size of the insulation structure are not properly selected, if these gaps are set too small, it may cause damage to the transformer. price. In order to correctly select the structure, material, size and manufacturing technique of the insulation, and to correctly determine the length of the effective insulation gap, it is necessary to know the effects that the insulation of the transformer is subjected to during operation.
Influence of electricity: The power transformer is usually connected to electricity when it is used, so its insulation is under the influence of the rated working voltage for a long time, and it should withstand this voltage indefinitely without any damage. In a transformer-operated power system, an instantaneous overvoltage may be caused due to normal switching operations or unexpected accidents. In a few rare cases, the overvoltage reaches nearly four times the phase voltage. The times of these voltages are measured in hundredths of a second, and generally it does not exceed 0.1 seconds. resin type transformer
The overvoltage of the rated working voltage and the nature of the switching operation mainly affects the main insulation of the coil, that is, the insulation of the coil to the grounding part and to other coils.
The main insulation of dry-type transformers often adopts the same insulating structural parts as oil-immersed transformers: insulating paper tubes, angle rings, component separators, etc. When designing the insulation of dry resin type transformer, in addition to ensuring the insulation strength, special attention should be paid to ensuring that there are enough air cooling ducts between the coils. And it is necessary to pay attention to the placement of insulating parts to ensure that the air can contact the coil most smoothly.
