Laminated Silicon Steel Core: Temperature Range -40°C to +120°C

Component Specifications

Definition

A laminated silicon steel core is a critical component in medium voltage current transformers, constructed from thin, insulated silicon steel sheets stacked together. This design reduces eddy current losses by limiting the path for circulating currents within the core material. The core serves to concentrate and guide magnetic flux generated by the primary current, enabling accurate secondary current induction for measurement and protection purposes. It is engineered to operate within specific voltage and frequency ranges, ensuring reliable performance in electrical distribution systems.

Working Principle

The core operates on electromagnetic induction principles. When alternating current flows through the primary winding, it creates a varying magnetic field. The laminated silicon steel core, with its high magnetic permeability and low hysteresis loss, concentrates this magnetic flux and channels it through the secondary winding. The laminations, insulated from each other, break up large eddy current paths, reducing energy losses as heat. This allows for efficient transformation of current from the primary to the secondary circuit while maintaining phase and magnitude accuracy for measurement.

Materials

Cold-rolled grain-oriented (CRGO) or non-oriented silicon steel sheets, typically containing 3-4.5% silicon, with thicknesses ranging from 0.23mm to 0.35mm. Each lamination is coated with an insulating layer (e.g., inorganic phosphate or oxide coating) to prevent interlamination short circuits. Core assembly may use adhesives or mechanical clamping, with materials resistant to thermal and environmental degradation.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Core Loss	≤ 1.5 W/kg at 1.7 T, 50 Hz
Permeability	≥ 1500 H/m at 1.0 T
Voltage Class	Up to 36 kV
Stacking Factor	0.95 - 0.97
Temperature Range	-40°C to +120°C
Operating Frequency	50 Hz or 60 Hz
Lamination Thickness	0.27 mm or 0.30 mm
Insulation Resistance	≥ 100 MΩ at 500 V DC

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 9001, IEC 60044-1, IEEE C57.13, DIN EN 61869-1

Parent Products

This component is used in the following industrial products

Medium Voltage Current Transformer Core Assembly

Precision wound magnetic core assembly for current measurement in electrical distribution systems

View Product Details

Engineering Analysis

Risks & Mitigation

Core saturation at high currents
Insulation breakdown due to moisture or contamination
Mechanical damage from vibration or shock
Thermal degradation from excessive losses
Interlamination short circuits reducing efficiency

FMEA Triads

Trigger: Overcurrent conditions exceeding design limits
Failure: Core saturation leading to inaccurate current transformation and potential damage
Mitigation: Design with adequate saturation margin, use protective relays, and specify correct current ratings

Trigger: Poor insulation or contamination between laminations
Failure: Increased eddy current losses, overheating, and reduced efficiency
Mitigation: Apply high-quality insulating coatings, ensure clean assembly environment, and perform insulation resistance tests

Trigger: Mechanical stress from clamping or vibration
Failure: Core deformation, increased magnetostriction noise, and degraded magnetic properties
Mitigation: Use controlled clamping force, incorporate vibration dampers, and follow precise stacking procedures

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Dimensional tolerance ±0.1 mm for lamination thickness, magnetic properties within ±5% of specified values, and assembly alignment within 0.5 mm

Test Method

Testing per IEC 60044-1 and IEEE C57.13, including turns ratio test, excitation characteristic test, insulation resistance test, and core loss measurement using Epstein frame or single sheet tester

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

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CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Laminated Silicon Steel Core

Manufacturer profiles associated with Laminated Silicon Steel Core.

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Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

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Frequently Asked Questions

Why is silicon steel used for transformer cores?

Silicon steel is used because it has high magnetic permeability and low hysteresis loss. The addition of silicon (3-4.5%) increases electrical resistivity, which reduces eddy current losses when the material is laminated, making it efficient for alternating current applications.

What are the benefits of laminating the core?

Laminating the core reduces eddy current losses by breaking up large conductive paths. Each thin sheet is insulated, limiting circulating currents that would otherwise cause heating and energy loss, improving efficiency and thermal performance in transformers.

How does core design affect current transformer accuracy?

Core design impacts accuracy by influencing magnetic flux behavior. Proper lamination, material grade, and assembly minimize losses and saturation, ensuring linear response across the current range. This maintains precise current transformation ratios and phase angles for reliable measurement and protection.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Laminated Silicon Steel Core