SGB Three-Dimensional Wound Core Transformer

Product Structural Characteristics

1. Core

The key component of the three-dimensional wound core transformer is the three-dimensional wound core, which is assembled by three identical single frames arranged in an equilateral triangular three-dimensional structure. Each single frame is formed by continuous winding of several trapezoidal strips in sequence; the cross-section of a single frame is nearly semicircular after winding, and the cross-section becomes a quasi-polygon very close to a perfect circle after assembly. The entire magnetic circuit features tight winding with no air gaps, and the high magnetic conductivity direction of the silicon steel strip is completely consistent with the magnetic circuit direction, resulting in low magnetic resistance and identical length of the three-phase magnetic circuit. These structural advantages achieve three-phase balance, reduce the third harmonic of the transformer, save raw materials, improve performance, lower losses, reduce no-load current and decrease operational noise.

2. Coils

The low-voltage winding is wound in a double-layer cylindrical type or foil type with balanced three-dimensional triangular low-voltage outlet terminals. The high-voltage winding adopts a continuous structure; the high-voltage coil has a large contact area with air, ensuring excellent heat dissipation and ventilation performance.

3. Base

Channel steel bases or mobile trolleys are equipped for the transformer according to user requirements.

4. Terminals

Low-voltage terminals adopt nickel-tin plated copper bars with wiring holes, which are welded to the coil ends and fixed on the clamps with insulators for convenient wiring. High-voltage terminals are connected via pre-embedded copper nuts.

5. Protection Class

IP00: No protective enclosure is equipped, suitable for box-type substations, power distribution cabinets, etc.

IP20: Equipped with a metal mesh protective enclosure that prevents the entry of 12mm foreign objects, suitable for indoor installation.

IP23: Equipped with a louvered protective enclosure that is resistant to rain, snow, insects, etc. Note: The transformer capacity shall be derated by 5% when using this type of enclosure.

6. Transformer Cooling Method

Transformers with a capacity of 125kVA and below generally adopt air natural cooling (AN) and can continuously output 100% of the rated capacity under this mode.

Transformers with a capacity of 160kVA and above adopt air forced cooling (AF). The cooling fans may remain off at a certain load capacity, and shall be activated when the load exceeds 70% of the rated capacity.

7. Temperature Control

The transformer is equipped with an automatic temperature control and protection system. According to user requirements, the system can realize functions including temperature display, cyclic detection, fan start/stop, over-temperature alarm, tripping, and computer communication interface.