As core equipment in power systems, oil-immersed transformers are crucial for grid security. However, long-term operation can lead to problems such as insulation aging, partial discharge, and oil leakage, necessitating systematic solutions to ensure reliability.
Insulation Aging and Temperature Control Issues
Degradation of insulation performance in oil-immersed transformers is often caused by high temperatures. Solutions include optimizing cooling system design, such as using forced oil air cooling (OFAF) or water cooling, to ensure the top oil temperature does not exceed 85°C. Regularly monitor winding hotspot temperatures and combine fiber optic temperature measurement technology for precise control. Furthermore, strengthen insulation oil management and regularly perform chromatographic analysis to detect dissolved gases (such as hydrogen and acetylene) to promptly detect potential faults.
Oil Leakage Control
Aging seals or weld defects can easily lead to oil leakage, threatening equipment insulation and polluting the environment. Solutions require a step-by-step approach: first, locate the leak using ultrasonic or infrared testing; then, install sealant gaskets or replace flange joints with metal expansion seals; and for weld leaks, use polymer composite materials for on-site repair or re-welding. Preventive measures include pressure seal testing every three years to ensure the tank's pressure-bearing capacity meets standards.
Partial Discharge and Insulation Maintenance
Moisture in cardboard insulation or metal suspension discharge can accelerate equipment degradation. It is recommended to install an online partial discharge monitoring system to analyze discharge pulse signals in real time. During maintenance, vacuum drying should be used to treat damp insulation components, and partial discharge levels should be controlled to ≤100pC. Deteriorated cardboard should be replaced regularly to ensure interlayer insulation thickness meets standards.
Combining these technical measures with preventive maintenance can significantly extend the life of oil-immersed transformers, reduce the risk of unplanned outages, and ensure efficient operation of the power system.