Impact of Encapsulating a Transformer with a Thermally Conductive Potting Compound

Magnetic components are the actual bottleneck for improving the power density in power conversion...

and above a given level of power, they can be considered as heat sources, and they need to be handled.

Encapsulating magnetic components with thermally conductive potting compounds is an outstanding solution to manage energy transfer. Low viscosity potting compounds enhance heat transfers by lling all gaps of the selected component. Not only do potting transformers benet from thermal dissipation; mechanical and environmental protection is also achieved by avoiding the intrusion of dust or unexpected particles and by protecting the equipment against shocks and vibrations.

In this document, a comparison between a transformer with and without potting is carried out.

Comparative Analysis

A transformer was driven to an operating point out of its nominal range so as to increase its temperature signicantly. Then, the transformer was encapsulated with low viscosity epoxy resin and tested under the same operating conditions. The pictures show the transformer before and after the potting and the temperature evolution measured during the tests.

Conclusions

The use of thermally conductive potting compounds enhances heat dissipation. Such improvement should be considered at the magnetic design stage so the use of the smallest components, which wasn’t previously considered, becomes possible.