Core Type Dry Type Power Transformer

As the professional manufacturer, we would like to provide you JUCEG Core Type Dry Type Power Transformer. And we will offer you the best after-sale service and timely delivery.The heart-type iron core structure is adopted, where the iron core column and the yoke form a closed magnetic circuit, and the winding is sleeved around the iron core column. The iron core is usually made by stacking high magnetic conductivity high-quality grain-oriented cold-rolled silicon steel sheets to reduce no-load loss and no-load current. The surface of the iron core is coated with special resin to prevent moisture and rust and to reduce operating noise. The winding is treated with epoxy resin casting or impregnation insulation to form a high-strength fiberglass structure, which has excellent electrical performance and mechanical strength. Insulating tubes are placed between the high and low voltage windings to increase electrical insulation, and spacer blocks and support plates are used to constrain the coils to ensure the stability and reliability of the windings. Core Type Dry Type Power Transformer mainly relies on air convection or forced air cooling for heat dissipation. When using natural air cooling (AN), the transformer can operate continuously at the rated capacity for a long time. When using forced air cooling (AF), the heat dissipation efficiency is improved by increasing the number of fans, and the output capacity of the transformer can be increased by 50%, suitable for intermittent overload operation or emergency accident overload operation.

Types of Dry Type Transformers:

1.Cast Resin Dry Type Transformer (CRT):

Uses epoxy resin to encapsulate windings, protecting them from moisture, dust, corrosion, and other environmental factors.

Suitable for high humidity areas, indoor installations, and fire-risk areas due to its non-hygroscopic, non-inflammable, and maintenance-free nature.

Available in ratings from 25 kVA to 12,500 kVA, with an insulation class of F (90°C temperature rise).

2.Vacuum Pressure Impregnated Transformer (VPI):

Impregnates windings with class H polyester resin under vacuum and pressure, eliminating air gaps or voids in the insulation.

Enhances mechanical strength, dielectric strength, and thermal stability.

Suitable for outdoor installations, seismic events, and temperature fluctuations due to its robust construction, moisture-resistant enclosure, and low thermal expansion coefficient.

Technical Data

Advantages

Excellent electrical insulation performance: After being impregnated, Core Type Dry Type Power Transformer can fully penetrate the epoxy resin into the winding interior, filling the gaps between the insulating materials and enhancing the overall insulation performance. The impregnated winding insulation layer is uniform and dense, reducing the risk of local discharge and improving the reliability of the transformer.

Enhanced mechanical strength: After impregnation, the epoxy resin solidifies closely with the winding, forming an integral structure, which enhances the mechanical strength and vibration resistance of the winding. The impregnation process can fix the position of the insulating materials and prevent them from loosening or shifting due to vibration or temperature changes.

Moisture and mold resistance: The impregnation process forms a dense protective film on the winding surface, effectively preventing moisture from entering and preventing the insulating materials from getting damp and moldy. Through moisture and mold resistance treatment, the service life of the transformer's insulating materials is extended, and faults caused by insulation aging are reduced.

Heat dissipation performance improvement: The impregnation treatment of Core Type Dry Type Power Transformer can fill the gaps between the insulating materials, reduce the air layer, and improve the heat conduction efficiency, helping the winding dissipate heat. Combined with a reasonable ventilation design, the impregnated dry-type transformer can also achieve good heat dissipation performance.

Cost-effectiveness: Compared with casting type, the impregnation treatment may use less epoxy resin material in some cases, reducing material costs. The impregnation treatment is suitable for windings of different shapes and sizes, has high process flexibility, and can meet diverse needs.