MechChem Africa July-August 2025

Purpose-engineered modular substations David Claassen of Trafo Power Solutions highlights the advantages of engineered modular substation solutions that are factory-built to include integrated dry-type transformers.

W ell known for its role in bringing dry-type transformer technolo gy to South Africa, Trafo Power Solutions’ success is now based on the company’s in-house design and engineer ing capability. “We supply complete, customised solutions that include dry-type transformers as one of many components,” says David Claassen, MD of Trafo Power Solutions. Modular substations, also known as E-houses, have become increasingly popular in recent years, originally as a solution for remote mining locations in Africa. Now, they are fast becoming a preferred alternative to brick-built substations. “From a cost perspective, modular substa tions are significantly cheaper, primarily because they are manufactured off-site and housed in a transportable steel structure. On-site con struction involves labour issues and health and safety requirements, which can cause delays and uncertainty. When manufacturing a modular substation, these issues fall under normal fac tory operations, allowing for quicker, higher quality, and more cost-effective builds,” he says. Other benefits include the installation, commissioning, and testing, all of which can be conducted under tightly controlled factory conditions. The most important aspect of any solution provided by Trafo Power Solutions, Claassen notes, is thoroughly understanding the client’s application. Modular substations are critical to the reliable operation of production equipment. Not only must the solution meet all operational requirements, but it must also be protected from dust, moisture, temperature, and other site-specific environmental hazards. Trafo Power Solutions manages the entire electrical design of its modular substations, which can include any of the equipment typically found in conventional substations, including the dry-type transformer, low- and medium-voltage switchgear, motor controllers, and automation equipment. “We're not typical product suppliers; we are solution providers. We ask the correct and ap propriate questions before we start designing because we aim to provide the best possible solution. We need to understand harmonics, load requirements, transport restrictions, site conditions, and all aspects of the operating environment,” says Claassen. Another major advantage for Trafo Power Solutions clients is that the company has experience with all tier one electrical product

suppliers. Preferences are based solely on client requirements, reliability, and fitness for purpose in the given environmental conditions. The dry-type transformer advantage Dry-type transformers are now widely accept ed, and their inherently safer nature enables Trafo Power Solutions to fully integrate them into its mobile substations. “It is possible to use an oil-filled transformer in a modular substation, but compared to dry-type transformers, these require a host of additional safety systems and protections. Structurally, a sealed base is required to contain

any oil leaks, and fire detection and suppression systems must be included, all of which add cost,” Claassen says. The core premise of a modular substation is the ability to transport the system to the site for ‘plug-and-play’ installation. Modular substa tions using dry-type transformers are lighter and more robust. On rough roads, despite suspension and packaging measures, peripheral equipment such as thermometers and relays on oil-filled transformers is likely to sustain damage, while oil leaks may develop, which will require additional onsite intervention. Dry-type transformers are simpler, lighter,

A dry-type transformer supplied by Trafo Power Solutions is installed within a modular substation, delivering safe and reliable power distribution for this application.

18 ¦ MechChem Africa • July-August 2025