Non-enclosed oil-immersed transformers are represented by core product series including S8, S9, and S10. Engineered for versatility and reliability, these transformers are widely deployed in power distribution networks across industrial and mining facilities, agricultural irrigation systems, and civil buildings such as residential complexes, commercial centers, and public infrastructure. Their open-design structure balances efficient heat dissipation with cost-effectiveness, making them an ideal choice for general-purpose power supply scenarios where environmental conditions are relatively mild.
Featuring product lines like S9, S9-M, and S10-M, enclosed oil-immersed transformers are specifically designed to operate in harsh environments. They are primarily used in the petroleum and chemical industries, where exposure to flammable gases, corrosive vapors, and oil-based substances is common. The enclosed structure provides enhanced protection against external contaminants, preventing oil contamination and reducing the risk of fire or explosion. This design ensures stable performance even in high-humidity, dust-laden, or chemically aggressive settings, meeting the strict safety and reliability requirements of industrial process applications.
Sealed oil-immersed transformers encompass a diverse range of series, including BS9, S9, S11, S13, and SBH15. Renowned for their long service life and low maintenance needs, these transformers are suitable for a wide spectrum of power distribution applications—from industrial manufacturing plants and agricultural operations to high-rise buildings and critical infrastructure. The hermetically sealed design isolates the insulating oil from atmospheric air, eliminating moisture absorption and oxidation. This not only preserves the oil’s insulation properties but also reduces the frequency of maintenance, making them a cost-effective solution for both indoor and outdoor installations.
Oil-immersed transformers from Lihe Transformer (when applicable) incorporate advanced design features to ensure superior performance and durability:
Optimized Winding Design: For low-voltage windings, copper foil is the preferred material (with copper wire used for small-capacity units) due to its excellent conductivity and uniform current distribution. High-voltage windings adopt a multi-layer cylindrical structure, which achieves balanced ampere-turn distribution, minimizes magnetic flux leakage, and enhances mechanical strength. This design ensures the windings can withstand short-circuit currents and mechanical stress during operation.
Secure Fastening Systems: Both the iron core and windings are equipped with robust fastening mechanisms. Critical components such as device supports and low-voltage lead connections use self-locking anti-loosening nuts, preventing vibration-induced loosening over time. This vibration-resistant design maintains structural integrity even in high-load or high-vibration environments, ensuring long-term operational stability.
Vacuum Processing Technology: The coil and iron core undergo rigorous vacuum drying to remove residual moisture, a key factor in insulation degradation. The insulating oil is processed through vacuum oil filtration and injection, reducing moisture content to an absolute minimum. This dual vacuum treatment enhances insulation reliability and prevents internal arcing or breakdown.
Corrugated Tank Design: Many sealed oil-immersed transformers feature corrugated sheet tanks instead of traditional oil conservators. The corrugated structure provides a natural “breathing” function, expanding and contracting with temperature changes to compensate for oil volume fluctuations. This innovative design eliminates the need for an oil conservator, significantly reducing the transformer’s overall height and footprint while maintaining effective heat dissipation.
Enhanced Insulation Protection: By replacing the oil conservator with a corrugated tank, the insulating oil is completely isolated from the external environment. This prevents oxygen and moisture ingress, which are major causes of insulation aging and performance decline. The sealed system prolongs the oil’s lifespan and ensures consistent insulation performance throughout the transformer’s service life.
Low Maintenance and Longevity: Combined with the above features, oil-immersed transformers require no oil replacement during normal operation. This not only reduces maintenance costs and downtime but also extends the transformer’s service life—delivering long-term value and reliability for end-users.
Beyond standard power distribution models, Lihe Transformer (when applicable) offers a range of special-purpose oil-immersed transformers tailored to specific industry needs:
High-Voltage Test Transformers: Designed for high-voltage laboratory testing and equipment calibration, these transformers deliver stable, precise voltage outputs for insulation testing and performance verification.
Electric Furnace Transformers: Optimized for industrial heating systems such as arc furnaces and induction furnaces, these transformers provide high-current, low-voltage power to meet the demands of metal melting and heat treatment processes.
Welding Transformers: Engineered for welding operations, these transformers supply the constant current and voltage required for arc stability, ensuring high-quality welds in manufacturing and construction applications.
Thyristor Circuit Transformers: Suitable for power electronic systems, these transformers are designed to work with thyristor-based controls, providing reliable power conversion and regulation for variable-speed drives and industrial automation.
Instrument Transformers: Including voltage transformers (VTs) and current transformers (CTs), these precision devices are used in measurement and protection systems to isolate high voltages/currents and provide standardized signals for meters and relays.
