Ghana Grid Company Limited has commissioned a new 120/145MVA Siemens Energy power transformer at its Afienya Substation in the Tema Region, a development aimed at improving electricity transmission capacity and enhancing supply reliability across surrounding communities.
The new transformer replaces the previous 66MVA unit, more than doubling the substation’s capacity and significantly improving its ability to meet rising electricity demand from Accra, Dawhenya, and nearby areas.
According to Ing. Dr. Benefit E.A.K. Patu, Supervisor for Electrical Maintenance at GRIDCo, the upgrade was necessitated by persistent overloading challenges caused by increasing demand on the network.
He explained that the earlier 50/66MVA transformer had reached its operational limit due to expanding distribution infrastructure operated by the Electricity Company of Ghana (Electricity Company of Ghana), making the upgrade essential for maintaining stable and reliable power supply.
The project enhances the capacity of the Afienya Substation and strengthens the National Interconnected Transmission System (NITS), ensuring improved stability for both current and future power demand.
The installation process involved several technical stages, including positioning the transformer on its foundation, assembling key components, and carrying out oil filtration to properly condition the transformer core and conservator.
Engineers also prepared the On-Load Tap Changer (OLTC) unit with oil to ensure efficient and stable operation.
During oil treatment, the technical team worked to reduce moisture levels in the transformer oil to acceptable parts-per-million (PPM) standards, with continuous monitoring recording single-digit results, indicating high-quality performance. These results were verified and approved by the technical services team.
The Protection and Control (P&C) team, led by Ing. Francis Koomson, conducted critical safety and testing procedures, including decommissioning old cables, installing new wiring, and performing trip tests to ensure proper system response under fault conditions.
He noted that the tests confirmed the transformer’s ability to isolate faults safely when required, enhancing overall system protection.
After full technical validation, the transformer was cleared for commissioning.
The project was executed by GRIDCo engineers led by Ing. Dr. Benefit E.A.K. Patu, with support from Ing. Francis Koomson and Mr. Albert Baiden-Amissah, Supervisor for Line Maintenance.
GRIDCo said the successful commissioning reflects its commitment to operational excellence, innovation, and reliable power transmission, adding that the upgrade strengthens its role as a backbone of the national grid system.