Oil Transformer Iron Core

The oil-immersed transformer core (oil-immersed transformer core) is the core component of an oil-immersed transformer, composed of silicon steel sheets with high magnetic permeability stacked together, and is used to form the magnetic circuit system of the transformer. Its function is to efficiently conduct magnetic flux, reduce eddy current losses and hysteresis losses, and ensure the stable operation of the transformer. Oil-transformer cores typically use cold-rolled oriented silicon steel sheets (such as 30Q130, 27ZH100, etc.), and their magnetic properties are optimized through processes like annealing, lamination, and clamping.

Customize from Our Standard Product Line

If you spot a near-match in our catalog, we can quickly modify our standard transformers for your application. Adjustments cover capacity, voltage class, cooling type and installation structure.

Build per Your Technical Documents

Send us your specifications or drawings. Our engineering team reviews the design, validates all key parameters with you, and manufactures strictly in accordance with international standards.

Full Custom Design from Concept to Completion

Without formal detailed specs? Share your ideas and functional requirements. We partner with you to develop fully customized transformer solutions, from electrical design and structural layout through to insulation system.

Overview
Product Overview
Why Choose Bardeen's Oil Transformer Iron Core
Application
Technical Specifications
FAQ
Transportation Services & Process

Overview

Bardeen presents the oil transformer iron core designed to meet demanding power distribution and transmission needs with proven performance, durability, and efficiency. The oil transformer iron core is engineered for modern grids and infrastructure projects, blending traditional magnetic core principles with advanced manufacturing and materials technology. As part of bardeen’s IEC 220kV transformer product line and transformer solutions, the oil transformer iron core supports grid stability upgrades, renewable energy storage integration, and reliable operation across commercial and industrial applications.

Product Overview

Product Overview and Key Features

The oil transformer iron core utilizes high‑grade electrical steel laminations assembled into a tightly stacked, low‑loss core structure. Precision‑pressed laminations reduce eddy current losses, and advanced annealing processes minimize magnetic hysteresis.

Core performance characteristics:
‑ Low loss and high efficiency: Adopt high‑grade silicon steel sheets (B30P105, B27R085), high permeability and reduced no‑load loss, complying with GB/T 25289 and IEC 60404. Stepped stacking or inclined joint processes optimize magnetic flux distribution.

‑ Low‑noise design: Insulating coating on silicon steel sheets suppresses magnetostriction‑caused vibration, noise ≤50dB. Multi‑stage binding or epoxy resin curing prevents core loosening.

Core performance characteristics continue:
‑ High mechanical strength: Steel strap or fiberglass strap binding avoids core deformation under short‑circuit current impact. Oil‑immersed cooling, long‑term temperature rise ≤65K.

‑ Corrosion resistance and insulation: Phosphating / oxidation surface treatment for transformer‑oil corrosion resistance. Single‑point core grounding eliminates multi‑point‑grounding eddy‑current loss.

Manufacturing Excellence and IEC Compliance
Bardeen’s manufacturing adheres to international standards. Precision stacking, controlled clamping forces and flatness tolerances lower magnetostriction noise and vibration. Full loss, permeability and dimension inspection before delivery.

Technical Advantages and Innovations
‑ Low‑Loss Lamination Materials: High‑grade uniform‑thickness electrical steels for low no‑load loss and improved energy efficiency.
‑ Tight Stacking and Interlaminar Insulation: Optimized stacking and high‑performance coatings suppress eddy currents with reliable dielectric separation.
‑ Core Clamping and Stress Control: Optimized clamping pressure distribution reduces local stress and thermal‑cycling failure risks.
‑ Oil‑Optimized Core Geometry: Structure promotes natural / forced oil circulation, enhances heat transfer and continuous loading capability.

Why Choose Bardeen's Oil Transformer Iron Core

Selecting bardeen’s oil transformer iron core means choosing a product backed by a company experienced in transformer engineering and high‑voltage production. Bardeen’s IEC 220kV transformer experience, commitment to material quality, and focus on energy efficiency translate into iron cores that support lower operational costs and enhanced reliability. The oil transformer iron core is engineered to meet the needs of transmission networks, distribution systems, and renewable integration projects, supporting critical grid stability upgrades and renewable energy storage initiatives with proven magnetic and thermal performance.

Application

Application Scenarios

Transmission and distribution substations requiring high efficiency and low‑noise performance.

Grid stability upgrade projects with dynamic‑loading predictable‑performance requirements.

Renewable energy & energy storage facilities facing frequent cycling and variable generation conditions.

Industrial plants needing durable long‑service‑life power distribution components.

Commercial campuses for stable and reliable power system operation.

Technical Specifications

Product Type	Oil Transformer Iron Core
Applicable Voltage Grade	Up to 220kV IEC‑compliant transformer systems
Silicon Steel Options	B30P105, B27R085 high‑grade grain‑oriented electrical steel
Noise Performance	Controllable below 50dB
Allowed Temperature Rise	≤65K (oil‑immersed operating condition)
Grounding Design	Single‑point grounding for core assembly
Applicable Standards	GB/T 25289, IEC 60404

FAQ

Frequently Asked Questions

Q1: Are your transformer accessories (tanks, cores, radiators) suitable for non‑standard transformer models? Do you support customisation based on drawings?A1: Absolutely. We are not only a manufacturer but also a provider of customised solutions. Whether you provide hand‑drawn sketches, used part samples, or PDF drawings, our technical team can produce precise CAD production drawings for you. For cores, we can tailor the stacking scheme of grain‑oriented silicon steel sheets according to your loss requirements; for tanks, we can adjust wall thickness and reinforcement structures based on insulation class.

Q2: How do you ensure that the cores or clamping frames you produce match the performance of my original transformer design?A2: We implement full‑process quality traceability. For cores, we strictly test flux density and specific loss to ensure they meet or even exceed national standards. For clamping frames (clamps), we pay special attention to punching position accuracy and galvanising/anti‑corrosion treatment, and provide CMM (coordinate measuring machine) inspection reports for critical dimensions, ensuring seamless installation upon receipt.

Q3: What materials are used for the transformer tanks and radiators? How do you prevent rusting?A3: We conventionally use high‑quality cold‑rolled steel plates (Q235B or Q345R). For rust prevention, we perform strict shot‑blasting to remove mill scale, followed by epoxy coal tar paint or polyurethane topcoat, with a dry film thickness strictly controlled above 120μm. For radiators (fin‑type radiators), we place special emphasis on internal pickling and phosphating treatment to ensure that the transformer oil is not contaminated during circulation.

Q4: Are the silicon steel sheets for the cores imported or domestic? Are the clamping frames strong enough?A4: We offer two options – Baowu Steel and Nippon Steel – to suit different budget requirements. For clamping frames (clamps), we use high‑strength steel formed in one stamping process, followed by vibration ageing treatment to relieve internal stress. This ensures that the clamps do not deform during a transformer short circuit, firmly securing the core.

Q5: What is the minimum order quantity (MOQ) for individual accessories? Can you supply just 1 set for emergency replacement?A5: We adhere to flexible supply. Although bulk orders enjoy better unit prices, we understand the urgency of the maintenance market and support single‑set orders. Whether you need 1 radiator or 1 core set, our production line responds quickly, and small‑batch orders receive the same process standards as large orders.

Q6: What is the warranty period for the accessories? What if I find slight dimensional deviations after receiving the goods?A6: We provide a 12‑month quality guarantee (from the shipping date). If any installation issue is caused by our manufacturing errors, we commit to unconditional replacement or return, and we will bear the two‑way freight. Meanwhile, we recommend that before mass production, we can make a first‑article sample for your approval before proceeding with full‑scale production.

Q7: How do you prevent impact damage to cores and radiators during long‑distance sea or land transport?A7: We use export‑grade, fumigation‑free wooden crate packaging. For cores, we employ vacuum‑sealed moisture‑proof aluminium foil bags with desiccants to prevent rust from moisture during transit. For radiators and tanks, we fill them with 0.02MPa dry air and seal the openings, and secure them with external steel frames to ensure no movement inside the container.

Transportation Services & Process

1. Heavy‑Lift & OOG Expertise

Specialized handling for Over‑Out‑of‑Gauge (OOG) cargo. We manage the entire process for heavy transformers, from custom crating and vacuum packaging to flat‑rack, break‑bulk, or Ro‑Ro shipping.

2. Customs & Compliance Management

Expert handling of complex export/import documentation, HS codes, and destination country regulations. We ensure smooth customs clearance to avoid costly delays.

3. Real‑Time Visibility & Risk Control

24/7 GPS tracking and milestone updates. Comprehensive cargo insurance covering all risks from origin warehouse to destination site.

4. Emergency Response

Prioritized air freight and expedited sea options for critical breakdowns. We minimize downtime by getting your replacement transformer or parts there faster.

Process

Assessment & Planning

We analyze the dimensions, weight, and route to design the optimal transport plan.

Professional Packaging

Seaworthy packing