As a widely used core equipment in power systems, oil-immersed transformers occupy an important position in the power transmission and distribution field due to their mature technology and stable performance. At the same time, affected by structural and material characteristics, they also have certain limitations. The following will detailedly analyze the core advantages and disadvantages of oil-immersed transformers.
In terms of advantages, first, it has excellent heat dissipation efficiency. Transformer oil has both insulation and heat dissipation functions. Through natural convection or forced circulation of oil, it can quickly dissipate the heat generated by the iron core and windings, adapting to large-capacity and high-load operating scenarios, and can meet the power transmission needs of 1000MVA and above large-scale units. Secondly, the insulation performance is reliable. The insulation strength of transformer oil is much higher than that of air, which can effectively isolate the current leakage between the windings, iron core and shell, improve the safety of equipment operation, and the service life can reach 20-30 years. In addition, the technology is mature and the maintenance cost is low. After long-term development, its design and manufacturing processes have been very improved, with strong accessory versatility. Daily maintenance mainly involves regular inspection of oil quality and oil replenishment, resulting in low operation and maintenance difficulty and controllable cost.
Its disadvantages cannot be ignored either. First, there is a potential fire hazard. Transformer oil is a flammable liquid. If the equipment's seal fails or a fault occurs, oil leakage is likely to cause a fire when encountering high temperature or electric sparks. Therefore, special fire prevention facilities need to be equipped, which increases the site construction cost. Second, it has a large volume. Limited by the heat dissipation structure and the storage demand of insulating oil, the volume of oil-immersed transformers is usually larger than that of dry-type transformers, which has high space requirements for the installation site and is not suitable for narrow spaces or internal scenarios of high-rise buildings. Third, the environmental adaptability is limited. In low-temperature environments, the viscosity of transformer oil will increase, affecting the heat dissipation effect; at the same time, if the oil ages or is contaminated, the insulation performance will be reduced, requiring regular oil quality treatment, which increases the operation and maintenance workload.
