Transformer supplier Trafo Power Solutions is offering dry-type mini substations as a complete and customisable electrical distribution solution for several applications.

“Mini substations generally include oil transformers, but Trafo Power Solutions is now able to design and deliver dry-type mini substations using the well-proven and reliable transformer technology of dry-type transformer manufacturer Hammond Power Solutions,” says Trafo Power Solutions MD David Claassen.

He adds that the company is using the latest cast-resin dry-type transformer technology. The benefit of using these transformers is that the windings are completely sealed, so that they are able to withstand up to 95% humidity and a high level of pollution.

Claassen mentions that there has been a significant increase in the uptake of the company’s customisable transformers in Africa for a variety of applications, and this makes it probable that the mini substations will be equally well accepted.

Dry-type mini substations are safer, owing to less fire risk and require less maintenance than mini substations built using oil-cooled transformers. Further, the substations are an environment-friendly option because they are completely green – no fossil fuels are used and there is no possibility of environmental contamination through oil spills.

Trafo Power Solutions specifically designs and customises its mini substations and transformers according to client specifications and applications.

Claassen says the company had to design a “special” ventilation system for its mini substations, as the enclosure must be well sealed to prevent dust and moisture entry, but also allow sufficient air flow to cool the transformer. While maintaining IP54 rating, the fan system is able to adequately cool the transformer, he adds.

Claassen states that mining is currently the main application for dry-type mini substations; however, there is growth potential in utility and infrastructure applications over the next five to ten years.

The company is working on mini substation projects in Africa that will be executed in the second and third quarters of this year.

Dry-Type Transformer Installations in Africa

The company is installing the transformers in the construction, as well as water- and wastewater treatment industries in South Africa.

“Trafo Power Solutions is working on projects in Mozambique and Sierra Leone, to name a few countries, but has also been active in East, Central and West Africa,” notes Claassen.

The company is also supplying two 3 000 kVA transformers to the Bisie tin mine, in the Democratic Republic of Congo. The transformers, manufactured by Hammond Power Solutions, arrived in South Africa at the end of last month.

“The solution being supplied to the mine is particularly customised, because the transformers will be built into modified shipping containers, which is being done in-house,” Claassen enthuses, adding that each container is modified in such a way that it becomes a substation.

He explains that the road to get to the mine is “extremely challenging” and the substations are being designed in such a way to withstand the intense vibrations and forces which will be experienced during transportation to site. The transformers themselves have also been specifically designed to withstand these conditions providing an extra measure of assurance.

The complete solution for the mine is built and tested in South Africa and will be installed between August and September this year.