10 kV 400 kVA Iron Core for Dry-Type Transformers

Transformer Iron Core Overview

Designed for distribution transformers, this 400 kVA 10 kV laminated core is made from cold-rolled grain-oriented (CRGO) steel coils for superior magnetic performance. It is available in IEC or ANSI configurations and provides a cost-effective, rugged solution for medium-voltage applications, with superior thermal performance, minimal losses, and extended service life under demanding load conditions. The core is ideal for utility networks, industrial plants, and commercial facilities that require stable and continuous power supply.

Features

Rated voltage: 10 kV, expandable to 35 kV. Power capacity: up to 400 kVA. Material: high-quality cold-rolled grain-oriented silicon steel. Manufacturing method: stacked silicon steel sheets. Assembly: stabilized by core clips, lifting ears, and pull rods. Finish: red paint for oil-immersed transformers and blue paint for dry-type transformers. Installation: ideal for indoor use, with an optional enclosure for outdoor applications. Standards: designed and tested according to IEC, ANSI, or customized standards.

Key Performance Indicators

Iron loss (core loss): the energy lost in the core through hysteresis and eddy currents during operation. Lower iron loss means higher transformer efficiency and is the core standard for judging silicon steel sheet quality. Magnetic permeability: the ability of the core to conduct magnetic flux. Higher permeability reduces the exciting current and improves core utilization. Saturation magnetic flux density: the maximum flux density the core can withstand. Exceeding this value causes a sharp increase in exciting current and, in severe cases, can damage the transformer.

Customization and Documentation

Custom configurations are available on request. Detailed CAD drawings and dimensional diagrams are provided upon inquiry, and the engineering team offers tailored designs for specific project requirements, including core dimensions, stacking factor, and joint configuration.

Applications

The core is widely used in public buildings, commercial complexes, renewable energy systems, and industrial facilities, providing a versatile power solution for indoor dry-type transformer installations.

Frequently Asked Questions

Q: Why is CRGO steel used for transformer cores?

A: Cold-rolled grain-oriented steel has a controlled crystal orientation that aligns magnetic domains in the rolling direction, giving low core loss and high permeability along the magnetic path of the transformer.

Q: What is iron loss and why does it matter?

A> Iron loss is the sum of hysteresis and eddy current losses in the core. Lower iron loss reduces no-load power consumption, lowers operating temperature, and improves transformer efficiency.

Q: What is the difference between core loss and copper loss?

A: Core loss occurs in the magnetic material whenever the transformer is energized, while copper (load) loss occurs in the windings and depends on the load current. Both contribute to total loss.

Q: Why are dry-type transformer cores painted blue?

A: The finish color is a factory convention: blue paint is used for dry-type transformer cores and red paint for oil-immersed transformer cores, mainly for identification and corrosion protection.

Q: Can the core be customized for other ratings?

A: Yes. Core geometry, grade of silicon steel, stacking factor, and joint design are tailored to the transformer rating and loss targets.

Q: What tests verify core quality?

A: Core quality is verified by Epstein frame measurement of specific total loss, magnetic induction at 800 A/m, stacking factor, and dimensional inspection of the assembled core.

For core drawings and a quotation for your 10 kV dry-type transformer project, contact our engineering team with your rating and loss requirements.