Trafo Power Solutions is extending the benefits of dry-type transformers by offering customised dry-type mini substations as a complete and customisable electrical distribution solution for users in mining.
“Using the well-proven dry-type transformer technology from global leader Hammond Power Solutions (HPS), we are now able to design and deliver mini substations that are specific to customer requirements,” says David Claassen, Managing Director.
Mini substations are traditionally built with oil-cooled transformers, explains Claassen, but the incorporation of dry-type technology makes the new offering safer due to less fire risk. In addition, dry-type units require less maintenance and present no possibility of environmental contamination through oil-spills. The units include a medium voltage switchgear for the incoming power source, a primary step-down transformer and a low voltage distribution board all contained within an enclosure.
“Customers have flexibility when it comes to the design and manufacture of the enclosure, as we can use various thicknesses of mild steel to suit the harshness of the conditions, and provide options for mobility such as a wheeled base or a skid-mounted base,” he says. “We also give the customer the freedom to choose their preferred brands on the medium voltage and low voltage switchgear.”
The capacity range offered is from 315 kVA up to 1,000 kVA, with a variety of voltages from 3.3 kV up to 11 kV on the medium voltage side and from 400 V to 1,000 V on the low voltage side.
“The transformer itself is specifically designed for Trafo Power Solutions by HPS in Italy according to our specifications, conforming to the IEC 60076-11 standard for dry-type units,” says Claassens. “Headquartered in Canada, HPS has over a century of experience in transformer design and manufacture, so have fine-tuned the application of transformers in mini substations for a range of environmental conditions. Trafo Power Solutions conducts the in-house design of the fit-for-purpose enclosure.”
He notes that an issue previously restricting the use of dry-type transformers in mini substations has been the provision for adequate cooling in an enclosure that is usually located outdoors.
“The enclosure must be well sealed to prevent the ingress of dust and moisture, but must still allow sufficient air flow to cool the transformer,” he says. “This challenge has been solved by the application of a specialised dual fan system, which pulls in fresh, cool air while simultaneously extracting the hot air.”