Oil-immersed transformers Project Background
Nigeria is the first largest economy in Africa, with a large population and strong demand for industrial and residential electricity, but the grid infrastructure is weak, most transformers have been in operation for more than 20 years, and there are problems such as aging equipment, insufficient capacity, excessive losses, frequent failures, etc. Lagos, as the largest city and economic center of Nigeria, the problems of insufficient power supply and poor voltage quality are particularly prominent, and large-scale blackouts often occur, Voltage fluctuations, etc., seriously affecting the lives of residents and industrial production.
At the beginning of 2025, the National Electric Power Company of Nigeria (NEPA) launched the Lagos State Distribution Network Upgrade Project, which plans to replace 200 old transformers, improve the capacity and reliability of the distribution network, and improve the local power environment. This project is a key livelihood project of the Nigerian government, which requires high quality of equipment, delivery period and after-sales service.
With its rich experience in African market (it has completed many power grid renovation projects in 12 countries in Africa), product quality in line with IEC standards and perfect after-sales service system, Jinma Electric successfully won one of the tender segments and is responsible for the supply of 20 sets of 11kV oil-immersed distribution transformers to cover the residential and industrial/commercial distribution in 3 areas of Lagos State.
Program design and adaptability
For the Nigerian power grid voltage fluctuation, load peaks and valleys, local construction conditions are limited, low level of operation and maintenance and other characteristics, Jinma Electric technical team for the project tailor-made design of the S11-M-RL type three-dimensional rolled iron core oil-immersed transformer, the product has both energy-saving, stable, easy to maintain, anti-stealing and other advantages, fully adapted to the Nigerian power grid reconstruction needs, the specific core strengths are as follows:
1. three-dimensional rolled iron core technology: compared with the traditional laminated iron core, three-dimensional rolled iron core adopts continuous rolling process, no seams in the iron core, uniform magnetic circuit, no-load loss is reduced by 20%, no-load current is reduced by 40%, the energy-saving effect is remarkable, and it can save a lot of electricity expenses for Lagos state every year, which is in line with the energy-saving policy of Nigeria’s energy saving department; at the same time, the structure of three-dimensional rolled iron core is compact, and the volume is 15% smaller than that of traditional transformer, which is easy to be transported and installed, and it is suitable for Nigeria’s local power grid renovation needs. Meanwhile, the compact structure of three-dimensional rolled iron core is 15% smaller than traditional transformer, which is easy to be transported and installed, and is suitable for the narrow installation site in Nigeria.
2. Wide voltage adaptation range: rated voltage 11kV, voltage adjustment range up to ±5%, can effectively deal with the problem of large voltage fluctuation in Nigeria’s power grid, to ensure that the equipment operates stably within the voltage fluctuation range, and to avoid equipment damage or power supply interruption due to too high or too low voltage.
3. Anti-theft design: Combined with the more common problem of local power theft in Nigeria, it adopts a fully enclosed anti-theft fuel tank, and installs a special seal on the fuel tank to prevent illegal power theft, and at the same time, the fuel tank is made of thickened steel plate to prevent man-made damages, and to reduce the loss of equipment and safety hazards.
4. Easy maintenance design: the equipment adopts maintenance-free structure, long service life of transformer oil, no need for frequent replacement, and is equipped with clear oil level meter, pressure release valve and other components, which is convenient for local operation and maintenance personnel to carry out daily inspection and simple maintenance, and is suitable for the lower level of local operation and maintenance in Nigeria.
Certification and Documentation
Nigeria has strict compliance requirements for imported power equipment. All imported equipment must comply with IEC international standards and provide SON certification (Standards Organization of Nigeria certification), otherwise it cannot clear customs and pass the acceptance of grid access. In order to ensure the smooth progress of the project, Jinma Electric has prepared a full set of compliance documents in advance, as follows:
1. product certification: S11-M-RL transformer passed IEC 60076 international standard certification, SON certification (Nigerian Standards Organization certification), and the certification documents are complete to ensure that the equipment meets the local standards in Nigeria;
2. trade documents: in advance for the certificate of origin, phytosanitary certificates, packing lists, commercial invoices and other complete sets of trade documents to ensure smooth customs clearance of goods;
3. technical documents: provide detailed English technical manuals, installation drawings, factory test reports, third-party test reports, etc., which are convenient for customers to carry out installation, commissioning and operation and maintenance, and at the same time meet the acceptance requirements of the Nigerian Electric Power Authority (NEPA).
The advance preparation of these documents ensures that the customs clearance is completed within 24 hours after the arrival of the goods, avoiding demurrage charges and laying a foundation for the on-time delivery of the project.
Project Execution
In March 2025, 20 sets of transformers successfully completed production and testing, and were shipped from Guangzhou port, using a direct sea route to Lagos port, with full logistics tracking to ensure safe arrival of the goods. Considering the limited local construction conditions and unskilled operation and maintenance personnel in Nigeria, Jinma Electric made full preparations before shipment:
1. equipment marking: spraying clear Chinese and English marking for each piece of equipment, including product model, capacity, voltage level, operation precautions, etc., which is convenient for local operation and maintenance personnel to recognize and operate;
2. Training support: produce a detailed on-site installation guide video (English version), covering equipment installation steps, wiring methods, daily inspection points, fault troubleshooting methods, etc., and send it to the customer in advance, so that the customer can learn in advance;
3. After-sales guarantee: arrange professional technical team to provide remote technical support, customers can contact Jinma Electric technical team at any time when they encounter any problems during installation and commissioning to ensure that the problems are responded and solved within 24 hours.
After the equipment arrived at the port of Lagos, the technical team of Jinma Electric remotely guided the customer to carry out installation and commissioning, and completed the installation, wiring and commissioning of all the equipment in only 10 days, and the equipment was successfully put into operation.
Project Effectiveness and Customer Feedback
After the equipment was put into operation, after two months of stable operation, all the performance indicators have reached the design standard, the project results are remarkable:
1. Improvement of power supply stability: the frequency of power outage in three regions of Lagos State has decreased by 80%, and the voltage stability has increased to 99%, which completely solved the problems of voltage fluctuation and frequent power outage, and improved the environment of residents’ life and industrial production of electricity;
2. obvious energy-saving effect: compared with the old transformers, the 20 transformers can save about 150,000 US dollars in electricity expenses every year, which reduces the operating costs for NNPC;
3. Convenient operation and maintenance: the equipment runs stably, and the maintenance-free design reduces the workload of operation and maintenance, and the local operation and maintenance personnel can independently complete the daily inspection and simple maintenance through the installation guidance video and remote technical support.
Feedback from the local power distribution company: “Jinma Electric’s transformers operate with low noise and good heat dissipation, effectively solving the problem of frequent overheating and tripping of the transformer, and the equipment is easy to operate and maintain, which is very suitable for our local operation and maintenance level. Jinma Electric’s service is also very professional, remote technical support response in a timely manner, is our trustworthy partner.”
