Oil-Immersed Power Transformer – Reliable, Efficient Power Conversion Core for Global Power Systems

The oil-immersed power transformer is a fundamental and widely used power conversion device in global power transmission and distribution systems, manufactured in strict accordance with IEC 60076 and GB 1094 international and national standards. Taking high-quality mineral insulating oil as the core insulation and cooling medium, it relies on the principle of electromagnetic induction to realize voltage conversion, energy transmission and distribution, and is an indispensable core equipment for connecting power generation, transmission, distribution and electricity consumption. Widely applied in power grids, industrial parks, large-scale mining areas, renewable energy bases, municipal infrastructure and high-rise buildings worldwide, it is favored by power companies, engineering contractors and industrial enterprises in Africa, Southeast Asia, Central Asia and Latin America for its mature technology, stable performance, strong overload capacity and long service life.

1. Core Technical Parameters & Customization Capabilities

Our oil-immersed power transformer covers a full range of capacity and voltage configurations, with flexible customization options to meet the diverse power supply needs of different regions, scenarios and load types, ensuring perfect matching with the user’s power system.

Full-Range Technical Specifications

Rated capacity: Ranges from 30 kVA to 50,000 kVA, covering small-scale terminal power distribution, medium-sized industrial load supply and large-scale power grid transmission scenarios. High-voltage side rated voltage: 6 kV, 10 kV, 35 kV, 110 kV (optional 220 kV for ultra-high voltage scenarios), fully compatible with the high-voltage power grid standards of most countries and regions.

Low-voltage side rated voltage: 0.4 kV, 10 kV, 35 kV, which can be flexibly configured according to the user’s low-voltage power distribution requirements. Rated frequency: 50Hz/60Hz, adapting to the power grid frequency requirements of different regions, with strong cross-border compatibility. Common connection groups: Dyn11, Yyn0, Yd11, which can effectively suppress third harmonic interference, improve power quality, and meet the power supply needs of different types of electrical equipment.

Impedance voltage: 4%–17%, which can be optimized according to the load type to effectively limit short-circuit current and protect the transformer and connected power distribution equipment from damage. Cooling methods: Natural oil circulation (ONAN) as standard, suitable for medium and small capacity and light load scenarios; forced oil circulation (OFAF) optional for large capacity and high-load continuous operation scenarios, ensuring efficient heat dissipation and stable operation.

Insulation grade: Mainly F grade (155℃), with optional H grade (180℃) for high-temperature working environments, effectively extending the service life of the transformer under harsh conditions. The overall efficiency of the transformer reaches over 98.5%, and the no-load loss and load loss are optimized according to energy efficiency standards, meeting the global green energy-saving and environmental protection requirements.

Comprehensive Customization Services

To adapt to the diverse needs of global users, we provide one-stop customization services. According to the local power grid standards and site conditions, we can customize the voltage level, capacity, connection group and impedance voltage of the transformer. For outdoor installation in high-temperature, high-humidity, coastal salt-spray or high-altitude areas, we offer enhanced anti-corrosion, dust-proof and insulation treatment, including epoxy zinc-rich primer + topcoat anti-corrosion coating and reinforced insulation structure.

For scenarios requiring frequent voltage adjustment (such as areas with unstable grid voltage), an on-load tap changer (OLTC) can be configured to adjust the output voltage without power failure, ensuring continuous power supply. For environmentally sensitive areas such as urban centers and ecological reserves, FR3 natural ester eco-friendly insulating oil is optional, which is biodegradable, non-toxic and fire-resistant, further improving environmental protection performance. Additionally, we can customize the transformer’s installation method (floor-mounted, pole-mounted), protection level (IP20/IP23) and dimensions to fit the user’s on-site installation space.

2. Advanced Structure & Core Competitive Advantages

The oil-immersed power transformer adopts a scientific structural design and high-quality raw materials, integrating high efficiency, reliability, safety and environmental protection, with outstanding performance in all aspects, making it stand out among similar products.

High-Efficiency Energy-Saving Design

The transformer core is made of high-permeability cold-rolled silicon steel sheets with an optimized step-lap or roll-core structure, with shear burrs controlled below 0.02mm. The core manufacturing process adopts a no-paint design, which minimizes no-load loss and no-load current, reducing energy consumption during light load or no-load operation. The winding adopts high-quality oxygen-free copper wire (or optional high-conductivity aluminum wire for cost control), with a tight and concentric winding structure and advanced vacuum impregnation process.

The insulation structure is optimized, and semi-oil path and prefabricated insulation materials are adopted, which effectively reduces load loss and improves the overall energy efficiency of the transformer. The low-loss design not only significantly reduces the user’s electricity consumption and operational costs, but also reduces carbon emissions, in line with the global green energy development trend and national “double carbon” strategy requirements. Even under 20% overload conditions, the transformer can operate stably for a long time, with an average temperature rise reduced by 10K compared with ordinary models, effectively extending the service life (up to more than 30 years under normal operation).

Reliable Oil-Immersed Insulation & Cooling System

The transformer uses high-quality mineral insulating oil with excellent insulation performance and heat dissipation effect, which can effectively insulate the winding and core, and quickly dissipate the heat generated during operation, ensuring the transformer operates within the safe temperature range. The oil tank adopts a fully sealed corrugated structure (for medium and small capacity) or a conservator structure (for large capacity), which can effectively isolate the transformer oil from the air, prevent oil oxidation and deterioration, and avoid the intrusion of dust and moisture.

All sealing parts are made of high-quality aging-resistant acrylate materials, with one-time molding technology without interfaces, ensuring the tightness of the transformer and reducing the risk of oil leakage and maintenance frequency. The cooling system adopts a reasonable oil circuit design, which realizes efficient circulation of insulating oil, and the heat dissipation effect is 30% better than ordinary transformers, ensuring stable operation even under long-term full load or high-temperature environments.

Strong Short-Circuit Resistance & Comprehensive Safety Protection

The winding and core are reinforced with special structural designs, with strong mechanical strength, which can withstand the impact of short-circuit current and avoid winding deformation or damage. The transformer is equipped with a complete set of protection devices, including gas relay, pressure relief valve, temperature controller, oil level indicator and lightning protection device, which can monitor the operating status of the transformer in real time.

In case of abnormal conditions such as overheating, oil leakage, gas accumulation, overvoltage or lightning strikes, it can issue an audible and visual alarm in time, and can be connected to the power distribution system to realize automatic power cut-off, effectively protecting the transformer and the safety of the power grid. The transformer’s shell is made of high-quality steel plate, with a firm structure and good impact resistance, suitable for outdoor installation in various complex environments such as industrial parks and mining areas.

Low Noise & Strong Environmental Adaptability

Through optimized structural design—such as adding noise reduction pads at the bottom of the oil tank, optimizing the core and winding structure, and adopting a full-filled insulation process—the noise level of the transformer is controlled within ≤55dB (measured at 1m distance), meeting the noise control requirements of residential areas, commercial centers and other sensitive environments.

The transformer has strong environmental adaptability, and can operate reliably in the temperature range of -30℃ to +50℃, adapting to harsh climate conditions such as high altitude, high temperature, high humidity and cold regions. The surface of the oil tank is treated with multi-layer anti-corrosion coating, which can effectively resist the erosion of rain, dust, salt spray and corrosive gases, making it suitable for long-term outdoor installation in various regions such as coastal areas, industrial parks, rural areas and mining areas.

3. Main Application Scenarios

The oil-immersed power transformer, with its full-range capacity, flexible configuration and stable performance, is widely applicable to various power transmission and distribution scenarios, and is the core equipment for ensuring stable and efficient power supply worldwide.

• Power Grid Construction & Transformation: As a key equipment in substations of different voltage levels (10kV, 35kV, 110kV), it is used for voltage conversion between high-voltage transmission lines and low-voltage distribution networks, balancing grid load and ensuring stable power supply for urban and rural areas. It is suitable for urban ring network power supply nodes, suburban power grid expansion and rural power grid upgrading projects.

• Renewable Energy Bases: Used in wind farms, solar power plants and other renewable energy projects, it collects the electric energy generated by wind turbines or photovoltaic modules, boosts the voltage to the required level (such as 35kV, 110kV), and then transmits it to the main power grid. The low-loss design is in line with the green development concept of renewable energy, and can further improve the energy utilization efficiency of the project.

• Large Industrial & Mining Enterprises: As the core of the total降压 station in large industrial parks, steel plants, aluminum smelters, chemical plants, data centers and mining areas, it converts high-voltage electricity into low-voltage electricity to meet the large power demand of industrial production, mining equipment and auxiliary facilities. It can withstand the impact of industrial load fluctuations and ensure continuous and stable production.

• Municipal Infrastructure & Public Facilities: Used in large-scale public facilities such as airports, high-speed rail stations, hospitals, shopping malls and sports centers, as well as municipal infrastructure projects such as urban subway, road lighting, water supply and drainage systems, providing reliable power support for public life and municipal operations. The low-noise and eco-friendly design is suitable for installation in urban centers.

• Cross-Border Power Transmission Projects: Adapt to the power grid standards of different countries and regions, and is used in cross-border power transmission and distribution projects between neighboring countries, with strong adaptability to different grid voltages and frequencies, ensuring the safe and efficient transmission of cross-border electric energy.