Dry-type transformers are widely used in various fields such as power distribution systems, industrial automation, and renewable energy. There are two common methods of manufacturing dry-type transformers: epoxy casting and vacuum impregnation.
The main difference between epoxy casting and vacuum impregnation is the method of insulation. The epoxy pouring method is to pour liquid epoxy resin into the gap between the coil and the iron core, and then solidify the resin by heating. This process is often called "epoxy potting." Vacuum impregnation, on the other hand, is the process of filling an insulating space with an insulating liquid (usually a high-quality epoxy) under vacuum pressure.
One of the advantages of epoxy casting is that it allows for a high level of encapsulation and isolation due to the viscosity and adhesive properties of epoxy. However, the resin itself may shrink over time, causing potential short circuits or failure of the system. Additionally, products made by epoxy casting may not have as high a mechanical strength as those made by vacuum impregnation.
Vacuum impregnation has good insulation properties and mechanical strength and is able to perfectly fill every void or gap in the transformer. The process of vacuum impregnation includes a thorough vacuuming, filling process and curing, resulting in a more complete insulation of the transformer.
In summary, both epoxy resin casting and vacuum impregnation methods are effective methods for manufacturing dry-type transformers. While the epoxy casting method offers better encapsulation and isolation properties, vacuum impregnation provides the highest level of insulation and mechanical strength. Ultimately, the choice between the two methods depends on the specific application and requirements of the transformer.
