Dry-type transformers go mainstream
December 2019
Electrical Power & Protection
The uptake of dry-type transformers in South Africa is now well beyond ‘niche’ applications, with local specialist Trafo Power Solutions installing a range of sizes across various sectors. “In recent months, we have been involved in projects with small 50 kVA low voltage lighting transformers, right up to 4,5 MVA medium voltage customised units,” says David Claassen, managing director of Trafo Power Solutions. “These have been installed in healthcare facilities, commercial buildings, educational institutions, mines and data centres, as well as at solar energy plants.”
Among its recent contracts, the company has supplied a number of lighting transformers. It has also provided outdoor instrument transformers to facilitate measurement of voltage on overhead lines. These cast-resin voltage transformers (VTs) typically have 33 kV, 22 kV and 11 kV primaries with 110 V secondaries with between 50 VA and 500 VA burden.
In the mining sector, a recent contract was the installation of 200 kVA dry-type transformers. This is often a corrosive environment in terms of water and dust, so a high ingress protection (IP) rating was applied. Claassen adds that a range of materials and paint can also be specified by the customer to further withstand corrosion.
Data centres are a fast growing aspect of the country’s digital economy, and Trafo Power Solutions is supporting this segment with its cast-resin transformers. It recently delivered and cold-commissioned two 2 MVA units for a data centre in Cape Town.
“These facilities obviously require the highest levels of reliability and protection from their electrical and electronic networks,” says Claasen. “The windings and core of our units were designed for a K factor of 13, given the high non-linear load. An electrostatic shield was also installed, along with surge protection of the highest order.”
He notes that there was substantial time pressure to complete the contract, but flexibility and responsiveness at Trafo Power Solutions ensured on-time delivery.
At three small-scale solar plants, Trafo Power Solutions is providing three 800 kVA transformers which will step up power from 400 V to 22 kV. These applications involve a solar inverter for the 100% non-linear load, as well as an electrostatic shield between the primary and secondary windings.
Claassen emphasises that the business prides itself on the level of application engineering for each customer’s specific requirements. “We understand what we are supplying and the risks faced by the customer and we design the solution accordingly,” he concludes. “Industry is certainly showing their faith that dry-type transformers can be applied in a growing range of applications.”
Further reading:
Africa’s net-zero ambition must become operational
Schneider Electric South Africa
Electrical Power & Protection
Schneider Electric’s Rohit Chashta argues that the biggest gap in Africa’s green transition is not ambition but execution, and outlines how advisory services, bankable project roadmaps, digital visibility and SF6-free switchgear can turn sustainability commitments into measurable progress.
Read more...
High-efficiency half-brick DC-DC converters
Vepac Electronics
Electrical Power & Protection
The Supreme series half-brick DC-DC converters from Vepac Electronics use synchronous rectification for high conversion efficiency, in a six-sided metal case built to withstand harsh industrial and transportation environments.
Read more...
Zinc-based batteries power a more sustainable energy future
Electrical Power & Protection
Zinc-based batteries are gaining ground as a safe, recyclable and cost-effective energy storage option, from consumer electronics to grid-scale systems. The International Zinc Association’s Simon Norton explains why zinc is well placed to support the clean energy transition.
Read more...
Energas introduces lower-cost German gas genset for South African market
Electrical Power & Protection
Energas Technologies will supply R Schmitt Enertec’s new Energy Line genset to the South African market, offering German-engineered gas-to-power generation of 400 to 500 kW at a lower entry cost through focused standardisation and a simpler standalone architecture.
Read more...
ACTOM plays key role in large transmission substation project in Swellendam
ACTOM Electrical Machines
Electrical Power & Protection
ACTOM has been appointed to engineer, procure, construct and commission the 1000 MVA main transmission substation for the Overberg Wind Farm in Swellendam, one of the largest substations of its kind in South Africa.
Read more...
Reliable power conversion from high-voltage DC buses
Conical Technologies
Electrical Power & Protection
The MEAN WELL DDRH-240 from Conical Technologies is a high-reliability DIN-rail DC-DC converter with a wide 250 to 1500 V DC input range, deriving stable low-voltage power directly from high-voltage DC buses in renewable energy, storage, charging, railway and industrial installations.
Read more...
AES maintains a strong value and safety stance on boiler retrofits
Electrical Power & Protection
AES Commercial Director Dennis Williams explains when a boiler retrofit makes more sense than replacement, outlines the range of efficiency and emissions upgrades available, and draws the line at safety: a boiler not legally signed off is shut down, no exceptions.
Read more...
The grid needs to become more intelligent
Schneider Electric South Africa
Electrical Power & Protection
South Africa’s power grid is becoming bidirectional and far more dynamic as distributed energy resources proliferate. Schneider Electric’s Nishandra Bajinath explains why digitalisation, DERMS and aggregation are essential to keep this increasingly complex grid stable and efficient.
Read more...
ACTOM’s integrated electrical solutions reduce project risk and accelerate delivery
Electrical Power & Protection
ACTOM has secured multiple orders across four divisions for the Naos-1 hybrid solar and battery project in the Free State, demonstrating its integrated model for supplying the full electrical chain from high-voltage equipment to distribution transformers.
Read more...
Smarter energy management starts with intelligent electrification
ABB South Africa ABB Electrification Products
Electrical Power & Protection
ABB Electrification specialists Adeline Maleka and Nokulunga Dube explain how the convergence of electrification, digitalisation and automation is helping South African industries gain real-time visibility, reduce energy waste and build operational resilience.
Read more...