PTFE Insulation Technologies for Dry-Type Transformers

Dry-type transformers are widely used in urban commercial buildings, residential communities, industrial workshops, and indoor power distribution stations by virtue of their advantages of no oil pollution, low noise, and high safety. Different from oil-immersed transformers with oil medium heat dissipation and auxiliary insulation, dry-type transformers rely entirely on solid insulation materials and air convection for heat dissipation and insulation protection, which puts forward higher requirements on the temperature resistance, flame retardancy, dielectric stability, and heat dissipation performance of insulation materials. Traditional dry-type transformers mostly use epoxy resin pouring insulation, which has defects such as poor thermal conductivity, easy cracking after aging, and poor partial discharge resistance. Innovative PTFE insulation technologies are specially optimized for the working characteristics of dry-type transformers, solving multiple technical bottlenecks of traditional dry-type insulation systems PTFE SHEET.

PTFE insulation technology adapts to the air-cooled heat dissipation mode of dry-type transformers with excellent high-temperature resistance and heat dissipation compatibility. The operating temperature of dry-type transformers is significantly higher than that of oil-immersed transformers due to the lack of oil medium heat dissipation. Traditional epoxy resin insulation is prone to thermal aging, surface cracking, and insulation performance decline under long-term high-temperature air cooling conditions. PTFE insulation materials can work stably at 260°C for a long time, with excellent thermal stability, no thermal deformation and aging cracking. The smooth surface of PTFE insulation components is conducive to air convection and heat exchange, effectively improving the natural heat dissipation efficiency of dry-type transformers and reducing the long-term operating temperature of equipment.

In terms of partial discharge resistance, PTFE insulation technology has outstanding advantages suitable for dry-type transformers. Dry-type transformers are prone to air gap discharge and surface partial discharge due to solid insulation structure and air insulation gaps. Long-term partial discharge will gradually erode the insulation layer, leading to insulation aging and failure. PTFE materials have excellent arc resistance and partial discharge erosion resistance, which can resist long-term micro-discharge impact without surface carbonization and insulation attenuation. The uniform and dense molecular structure of PTFE avoids internal air gaps, effectively inhibiting the occurrence of partial discharge faults and improving the operational stability of dry-type transformers PTFE TUBE.

Flame retardancy and safety performance are core advantages of PTFE insulation technologies for dry-type transformers. As indoor power distribution equipment, dry-type transformers have extremely high safety requirements and need to avoid fire hazards caused by insulation failure. PTFE materials are intrinsically flame-retardant, with a limiting oxygen index as high as 95%, non-combustible, no open flame combustion, and no toxic and harmful gas release in high-temperature environments. Compared with epoxy resin materials that are easy to burn and decompose toxic gases at high temperatures, PTFE insulation greatly improves the fire safety level of dry-type transformers and meets the high safety standards of indoor power distribution equipment.

In addition, PTFE insulation technology solves the problem of difficult maintenance of traditional dry-type transformer insulation. Epoxy resin pouring insulation is an integral fixed structure, which is difficult to repair and replace once cracked and aged, and can only be replaced as a whole, resulting in high maintenance costs. PTFE insulation adopts modular assembly structure design, including detachable insulation sheets, flexible insulation sleeves, and standardized gaskets, which is convenient for daily inspection, local replacement and maintenance. This modular insulation design greatly reduces the later operation and maintenance cost of dry-type transformers and improves equipment maintainability.

With the continuous improvement of urban power grid safety standards and the popularization of indoor dry-type transformer equipment, high-performance insulation technology has become the key to the upgrading of dry-type transformers. PTFE insulation technologies, with their high temperature resistance, partial discharge resistance, flame retardant safety and convenient maintenance advantages, have become the mainstream innovative insulation scheme for new-generation dry-type transformers, promoting the safe and intelligent development of urban power distribution equipment.