ACTOM Distribution Transformers holds the exclusive 100% Negative Sequence Current Earth Return Transformer (NECRT) contract with Eskom, making it a critical supplier for South Africa's renewable energy infrastructure. The company's role is essential because a solar or wind farm requires an NECRT to energise and synchronise with the national grid. Without this transformer, renewable energy projects cannot generate power. This exclusivity positions ACTOM Distribution Transformers as a key enabler for new solar and wind farms connecting to Eskom's network across the country. The functionality of these NECRTs directly impacts the operational readiness and power generation capabilities of renewable energy installations. As the sole 100% NECRT contract holder for Eskom, ACTOM Distribution Transformers plays an unparalleled role in facilitating the integration of renewable energy sources into the national power grid.
Critical Grid Integration Technology
Negative Sequence Current Earth Return Transformers (NECRTs) are indispensable components within renewable energy collector substations, where they establish the critical earth reference for delta-configured power transformers. Lee Mbenge, Divisional CEO of ACTOM Distribution Transformers, stated that "NECRTs are indispensable in renewable energy collector substations, where they create the essential earth reference for delta‑configured power transformers." Mbenge added that "Without an NECRT, a solar or wind farm cannot energise, cannot synchronise with the grid and cannot generate power. This makes the NECRT a relatively small but absolutely critical component in the commissioning sequence of any renewable project."
The NECRT facilitates controlled neutral-earthing through its zig-zag (Interconnected Star) winding and integrated resistor assembly. This specific design allows for precise control over the earthing process, which is key for grid stability and safety. Beyond its primary earthing function, the NECRT also supplies auxiliary power necessary for the operation of substation equipment, ensuring that essential systems within the substation remain operational. A significant challenge in renewable energy integration is that plants generating power from inverter-based systems introduce elevated harmonic content, which exposes transformers to increased electrical stress. ACTOM's NECRTs are engineered to withstand these demanding conditions, ensuring long-term reliability and adherence to strict grid-code compliance. This resilience is vital for maintaining the integrity and efficiency of the renewable energy infrastructure.
Proven Reliability and Regional Reach
ACTOM's Negative Sequence Current Earth Return Transformers (NECRTs) are designed to endure demanding operational conditions, ensuring both long-term reliability and adherence to grid-code specifications. The company has reported zero failures across all its energised NECRT installations, showing their operational dependability. This track record of zero failures on all energised NECRT installations notes the strong engineering and manufacturing quality that ACTOM Distribution Transformers brings to the market. One recent application of this technology is the 273-megawatt (MW) Grootfontein solar photovoltaic (PV) project in the Western Cape, which has been completed and is now contributing to the national grid. The successful deployment at Grootfontein demonstrates the practical application and effectiveness of ACTOM's NECRTs in large-scale renewable energy projects.
Beyond its domestic deployments, ACTOM's NECRTs have been widely installed across South Africa. The technology's reach extends throughout the region, with units deployed in Eswatini, Botswana, Namibia, Zambia, Zimbabwe, Mozambique, the Democratic Republic of Congo (DRC), and Sierra Leone. This broad deployment notes the company's role in supporting renewable energy infrastructure across multiple African nations, providing essential components for various power generation initiatives. The consistent performance of these units across diverse geographical and operational environments further solidifies ACTOM's reputation as a reliable supplier in the renewable energy sector.
Ensuring Project Success and Quality
ACTOM supplied transformers to the Daamlaagte and Ilikwa PV solar projects, contributing to their operational readiness. The Negative Sequence Current Earth Return Transformer (NECRT) represents a small line item in project budgets, but its significance is substantial. The NECRT is a relatively small investment in the overall project cost, yet its absence or malfunction can bring an entire renewable energy project to a standstill. Delays in its delivery or issues with its reliability can halt an entire project's progress, leading to significant financial losses and missed commissioning deadlines. To prevent such delays and ensure operational integrity, Factory Acceptance Tests (FATs) are conducted. These tests are essential for verifying that each transformer meets the client’s technical specifications, performance requirements, and safety standards before it leaves the factory. This rigorous testing process confirms the unit's readiness for deployment and its capacity to integrate smoothly into renewable energy infrastructure. The careful verification procedures show the importance of each component, however small, in the successful commissioning of large-scale solar and wind farms, guaranteeing that every NECRT delivered by ACTOM is fit for purpose and ready to perform its critical function.
