Electricity and Control June 2025

Transformers, substations + the grid

previously worked only on production and supply, and with the new integrated transformer-inverter station it is now providing installation and commissioning services as well. These new capabilities are supported by colleagues in ACTOM’s HV Equipment Division in a training programme enabling transfer of skills and shared lessons across the company’s di”erent divisions. Looking at the potential market, Mbenge says ACTOM initially will focus nationally and in the SADC region – he points to renewable energy projects happening in Botswana, Namibia and eSwatini. He adds that the combined transformer-inverter station is also suitable for mining and other industrial sites where companies have installed their own solar or wind energy plants. The agricultural sector is another potential market and Mbenge notes that the integrated unit would serve especially well to support microgrids, extending electricity access to unserved areas that are inaccessible to the national grid. Key benefits and the value of localisation Among the main benefits of the integrated MV transformer-inverter station are that it is supplied as a containerised unit, making it easier to transport and quicker to install on site than would be the case with separate sourcing, supply, installation and commissioning of the various components. “It is, in e”ect, a plug-and-play solution,” says Mbenge. “There is no need for more cabling or connections on site, no big site teams working on an installation, the whole process is simplified.” Mbenge adds that the 4.4 MW integrated stations are supplied in a standard 20-foot container, and the 8.8 MW module in a standard 40-foot container. He also emphasises the benefits of localisation: supporting the development of local skills, local jobs, and local manufacturing, reducing logistics complexities and costs, and contributing to growing the South African economy. Asked about delivery lead times – he says, “about 20 weeks (5 months) from drawing approval by the customer”. This compares well against the standard lead time for imports which would be around 32 weeks (8 months). “Local support and maintenance o”er further benefits for the customer – in response time, language, availability of spares. In power generation, every hour counts. Quick access and local understanding enable faster turnaround times.” Mbenge adds that monitoring and control are built into the unit, and the so•ware included in the LV combiner box, which manages protection and control, is designed to communicate with the control centre for the site. This supports remote monitoring and quick responses on any anomalies that arise. The first units were produced at the ACTOM Power Transformers facility in Knights, east of Johannesburg, and going forward, ACTOM will be responsible for all production, quality control and maintenance support for the integrated MV transformer and inverter station.

He says the company is also working with academia, electrical engineering experts at the University of the North West and the University of the Witwatersrand, in investigating and understanding the specifics and variabilities of renewable energy, in order to optimise further new developments in the equipment it supplies in this sector. Markets The Power Transformers Division at ACTOM is already engaging with the market to extend the uptake of the integrated MV transformer and inverter station, reaching independent power producers, mainly via their EPC consultants and engineering consultants, Mbenge says. The containerised station is especially engineered for renewable energy projects and will serve BESS (battery energy storage) projects equally well – to support the supply of dispatchable energy to the grid. Mbenge adds that ACTOM is already working in this field, having supplied mainly electrical balance of plant on some of the first BESS projects. It is also working with Eskom’s NTCSA in supplying auxiliary transformers as part of the implementation of the Transmission Development Plan. He notes that the Transformers Division at ACTOM has

For more information visit: www.actom.co.za

JUNE 2025 Electricity + Control

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