With mining companies increasingly opting for on-site renewable-energy installations to ensure reliable power, and improve their environmental, social and governance (ESG) credentials, electrical equipment supplier Trafo Power Solutions’ dry-type transformers contribute to the ESG aspect by eliminating fossil fuel elements and fire risks.

Dry-type transformers not only cater well to the clean environments demanded by data centres but are also becoming more prevalent at remote mine sites, owing to their containerised design, and Ingress Protection-rated dust and water-resistant housings.

“The data centre business is a growing market, with similar load profiles and high levels of harmonics to mining. The data centre’s clean environment and reliability focus align well with the use of dry-type transformers, and this is where Trafo Power Solutions’ expertise comes into play, ensuring the most appropriate solution for an application,” confirms MD David Claassen.

He explains that the increasing use of variable-speed drives and inverters in mining leads to higher harmonic levels and, accordingly, Trafo Power Solutions designs transformers to compensate for additional heat generated by harmonics.

The company also designs cooling systems accordingly and ensures the insulation system can withstand peak voltages and earth currents caused by harmonics.

Trafo Power Solutions holds intellectual property rights on certain cooling technologies that are essential for transformers to withstand outdoor conditions. The cooling technology solutions it offers include naturally ventilated, forced-air and water-cooling solutions to dissipate heat while maintaining moisture and dust resistance.

Dry-type transformers are increasingly being integrated with battery energy storage systems, owing to their compatibility with inverters, notes Claassen, explaining that, since the transformers can be installed in containers or modules, they are a good fit for renewable-energy applications, including at mine sites.

Trafo Power Solutions avoids selling products without thorough engineering and testing to ensure that the designs are fit for purpose and reliable. As such, it conducts factory acceptance testing on every transformer manufactured, which clients can witness remotely or in person.

The company also performs site acceptance testing before energisation to ensure that transformers are installed correctly.

Claassen stresses the importance of simulation tools – such as finite element analysis and thermodynamic modelling – in the design process of dry-type transformers and their enclosures, which help test designs before manufacturing to provide reassurance of the design’s accuracy.

The tools simulate forces, temperatures and strains on the transformer, which Trafo Power Solutions uses for every first-time design.

Claassen also emphasises the importance of partnerships with companies, such as medium- and low-voltage dry-type transformer manufacturer TMC Transformers, which are specialists in the manufacture of dry-type transformers for nonstandard applications.

Dry-type transformers are rigid and can be transported over long distances without much concern for damage. Owing to the fact that the windings and core of dry type transformers are visible, it is easy to assess if any movement of the active part has taken pace during transport, unlike oil-cooled transformers.

These transformers are easier and more affordable to maintain, compared with oil-cooled transformers, while offering the benefit of aligning with ESG principles, such as safety, as dry-type transformers conform to class F1 fire protection standards.

“With minimal levels of maintenance needed, dry-type transformers offer reliable performance over lengthy life spans, with fewer risks and hazards compared with oil cooled transformers,” Claassen states.

To guide customers on maintenance planning, Trafo Power Solutions provides a maintenance manual with every installation, detailing the required frequency of service interventions – typically once a year for clean indoor environments and every six months under dusty outdoor conditions.

Trafo Power Solutions provides the necessary systems and personnel to timeously and professionally de-energise transformers before they can be cleaned, and advise on technical or other interventions for optimal performance.