Comprehensive Quality Control Throughout the Entire Manufacturing Process
Transformers are at the core of power transmission and distribution. Their quality directly influences the safety, stability, and efficiency of the power supply system. As a technology-driven enterprise in transformer manufacturing industry, we always put great emphasis on full-process testing and authoritative certification.
From incoming raw material inspection to finished product delivery.
From microscopic analysis of oil quality to performance verification of assembled units.
Covers raw materials, components, assembled units, and finished products.
Equipped with advanced international testing equipment.
Supported by a professional technical team.
Every product is able to meet the highest international and industry standards.
Raw Material & Component Testing – Quality Control at the Source
Insulation Materials
– We use advanced metallographic microscopes for microstructure analysis of key materials.
– Core parameters such as iron loss and dielectric dissipation factor exceed national standards.
– All purchased components must pass fundamental and extreme-environment tests.
Conductor Materials
– Full inspection for copper (T2/TU1) and aluminum (1060/6063).
– Pass spectrographic analysis, tensile testing and resistivity testing.
– The purity, conductivity, and processing quality can be fully assured.
Core Materials
OMEK strictly rejects substandard raw materials and only selects the best-quality core materials, including high-oriented silicon steel, amorphous alloys, and nanocrystalline alloys.
– OMEK only choose high-quality substrates with a silicon content of 3%–4.5%.
– We prefer ultra-thin sheets of 0.18 mm–0.3 mm, ensuring extremely low hysteresis and eddy current losses.
– We carefully inspect each sheet to achieve thickness uniformity and surface insulation coating performance.
– We verify inter-layer insulation resistance to prevent eddy-current circulation.
– We choose high-quality billets with precise Fe-B-Si composition for their ultra-high magnetic permeability and ultra-low loss characteristics.
– We carefully test key parameters such as saturation flux density and Curie temperature in order to achieve stable performance under different operating conditions.
– Our factories are equipped with cutting-edge instruments, including laser magnetic-property scanners and eddy-current loss analyzers.
– Our digital inspection system uploads test data of each batch to the cloud in real time, ensuring full traceability and verifiability.
– Every core’s performance can be reliably tracked and reviewed.
Insulating Oil Laboratory
Our factories are equipped with a full set of advanced instruments, including:
– Fully automated oil chromatograph
– Silent oil-free air compressors
– Micro-moisture analyzers
– Pour-point and cold-filter-point testers for petroleum products
– Performs dissolved gas analysis (DGA)
– Measures breakdown voltage
– Tests dielectric dissipation factor
– Covers multiple other critical parameters for insulating oil quality
– New oil must pass comprehensive inspections before use
– In-service oil is monitored through dual-layer checks, which are batch-based testing and quarterly testing
– Secures the long-term stability and reliability of insulating oil performance over the transformer’s lifetime
In-Process Testing of Semi-Finished Products
Coil Manufacturing Inspection
Automated Manufacturing System
– We employ advanced CNC winding machines and wire-laying machines to establish an automated production system.
– Program-controlled winding ensures standardization and high precision, effectively minimizing errors from manual operation.
Expert Supervision
– We have a technical team with over 10 years of experience in transformer coil manufacturing provides on-site supervision throughout the entire process.
– Key process controls include:
– Adjusting the tension of copper wire during payout
– Controlling interlayer spacing when wrapping insulation paper
– Managing pressure during coil pre-forming
Testing at Semi-Finished Stage
– Turn-to-turn insulation testing
– DC resistance measurement
– Full dimensional inspection
These tests help us with the electrical performance and physical structure of the coil meet the required standards
Core Manufacturing
– In OMEK, we implement strict quality control throughout the whole core manufacturing process, including cutting, stacking, curing, and assembly, achieving micron-level precision in the magnetic circuit
– Recheck the raw materials before cutting.
– Use CNC cutting machines to deliver tight dimensional tolerances.
– Remove any core sheets with excessive burrs.
– Calibrate levelness during stacking.
– Employ cross-lamination to control misalignment.
– Monitor stacking density in real time to ensure uniform magnetic circuits.
– Precisely control adhesive application and temperature curves.
– Test bond strength and magnetic properties to guarantee material performance.
– Measure the dimensions using 3D scanning before assembly.
– Control bolt torque with torque wrenches.
– Check the finished cores through excitation and noise testing.
– We give each semi-finished core a unique ID, thus we can conveniently trace the quality data.
– Strict full-process control brings precision and performance to semi-finished cores, laying a solid foundation for the efficient and stable operation of transformers.
Oil Tank & Structural Components
- Purchase of Oil Tanks
- In-House Processing
- Assembly and Final Verification
– We only cooperate with suppliers with pressure vessel production qualifications and ISO9001 certification.
– Incoming oil tanks undergo comprehensive inspection, including penetrant testing (PT), 24-hour pressure leak testing and dimensional tolerance and surface treatment checks
– Non-conforming tanks will be returned immediately.
– We use proprietary surface reinforcement technology. Secondary rust removal and electrostatic powder coating make the oil tanks better.
– Coating adhesion and zinc layer thickness are above industry standards, significantly improving corrosion resistance.
– Critical parts such as flanges and interfaces are precision-machined to maintain flatness errors below industry limits.
– Advanced positioning technology ensures precise alignment between the oil tank and the transformer body.
– Fastener torque deviation is controlled within 5%.
– After assembly, comprehensive sealing and mechanical strength tests are conducted.
– Thus, our oil tank not only has excellent structural stability but also withstands the demanding conditions of long-term transformer operation.
Complete Unit Assembly Quality Control
Transformer Body Assembly
Micron-Level Precision Assembly
– OMEK achieves micron-level precision in integrating the core, windings, and insulation components. Quality control has been extremely rigorous throughout the entire assembly process. This makes sure that all core components can integrate seamlessly.
Pre-Assembly Check
We accurately measure and test core and insulation components, and any non-conforming parts will be immediately removed.
Precision Assembly Process
Advanced CNC, robotic, and laser systems guarantee precise assembly and perfect alignment of all core and insulation components.
Post-Assembly Verification
We employs precise tools to check mechanical alignment, dimensional accuracy, winding ratios, electrical resistance, and insulation performance, so as to make all components meet standards.
Outcome
– Through rigorous full-process quality control, the transformer body assembly is always perfect. This provides a solid foundation for reliable and stable transformer operation.
Casting and Molding Process
– OMEK establishes a rigorous quality control system for the casting and molding process using professional full-process equipment, providing a solid foundation for the transformer’s insulation structure.
– Fully automated batching
– High-speed vacuum mixing
– Inspecting cavity sealing with a 2D vision system
– Preheating molds
– Vacuum casting tanks and precision metering pumps.
– Ultrasonic monitoring
– Intelligent temperature control system
– Temperature sensors
– 3D laser scanners, dielectric strength testers, and universal testing machines
– From material preparation to final inspection, professional equipment ensures the transformer’s insulation structure achieves both high dielectric performance and long-term stability.
Vacuum Oil Filling
– Using dual-stage rotary vane vacuum system
– This achieves a high vacuum state inside the tank, completely removing air and moisture from within the transformer.
– Using high-precision metering oil pumps to control the injection speed and volume.
– Using online vacuum monitors to safeguard the vacuum environment.
– Standing degassing.
– Micro-water analyzers and partial discharge detectors measure moisture content and partial discharge levels in the oil.
– When data meets standards, the transformer will proceed to the hot-oil circulation process.
– The oil will be heated to 60–80°C using a temperature control system and circulated through filters.
– This further removes impurities and gases from the insulating oil.
– From oil selection to vacuum filling, real-time monitoring, and post-treatment, each step is precisely controlled with advanced equipment.
– This ensures the vacuum oil filling process provides a solid foundation for the reliable performance of oil-immersed transformers.
Final Factory Testing & Verification
All transformers are subject to routine tests, type tests, and special tests according to GB/T 1094, IEC 60076, and customer requirements.
This makes sure that every OMEK transformer is ready to meet the market and long-term operational demands, delivering reliable, high-quality power solutions worldwide.
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