② Techical Data Of Three-phase Three Winding Power Transformer On-load Changer

High-Efficiency Power Transformer Solutions

A power transformer is a critical component in electrical systems, designed to efficiently transfer alternating current (AC) electricity between circuits at varying voltage levels. Ideal for stepping up or down voltages, these transformers ensure reliable power distribution in energy grids, industrial facilities, and commercial applications. Engineered for durability and performance, our power transformers meet international standards (IEC, IEEE) while prioritizing safety, efficiency, and sustainability.

​​Core Features & Benefits​​

​​High Efficiency & Energy Savings​​

Utilizing advanced core materials (e.g., amorphous alloy) and optimized winding designs, our transformers minimize energy losses (up to 30% lower than conventional models). This reduces operational costs and supports green energy initiatives.

​​Robust Reliability​​

Built with high-grade insulation systems and robust cooling mechanisms (ONAN, ONAF, OFAF), the transformers withstand harsh environmental conditions, voltage fluctuations, and long-term load demands. Thermal management systems enhance longevity.

​​Customizable Designs​​

Available in single-phase or three-phase configurations, with voltage ratings from 33kV to 765kV and power capacities up to 1,000 MVA. Custom solutions accommodate specific applications, such as renewable energy integration, urban substations, or mining operations.

​​Smart Monitoring & Safety​​

Equipped with IoT-enabled sensors (optional) for real-time monitoring of temperature, voltage, and load conditions. Advanced protection features (e.g., Buchholz relays, Buchholz alarms) prevent faults and ensure safe operation.

​​Eco-Friendly Compliance​​

Low noise levels (<75 dB) and non-toxic materials align with environmental regulations. Recyclable components minimize ecological impact.

​​Applications​​

​​Energy Transmission​​: Step-up/down transformers for grid interconnections and substation networks.

​​Industrial Use​​: Heavy machinery, manufacturing plants, and chemical industries requiring stable voltage supply.

​​Renewable Energy​​: Integration with wind/solar farms for efficient power evacuation.

​​Commercial & Urban​​: HVAC systems, data centers, and smart city infrastructure.

​​Technical Specifications​​

​​Voltage Range​​: 33kV to 765kV (medium/high voltage).

​​Frequency​​: 50Hz/60Hz.

​​Cooling Types​​: Air-cooled (ONAN), oil-forced air-cooled (OFAF).

​​Efficiency Class​​: IEC 61378 compliant (≥99% efficiency at full load).

​​Quality Assurance
​​

Each unit undergoes rigorous testing, including:

Insulation resistance and impulse voltage tests.

Load loss and no-load loss measurements.

Short-circuit withstand verification.

Certified by ISO 9001, ISO 14001, and KEMA for global compliance.

​​Why Choose Us?​​

​​20+ Years of Expertise​​: Proven track record in designing transformers for diverse industries.

​​Global Presence​​: Localized support with 24/7 technical assistance.

​​Competitive Pricing​​: Scalable solutions tailored to budget and performance needs.

​​Custom Solutions Available​​

From modular transformers for remote locations to eco-friendly designs for urban projects, we deliver end-to-end engineering, installation, and maintenance services.

1. Core Materials and Winding Design​

​Core Materials​

​Amorphous Alloy Cores:

Ultra-low iron loss (70–80% lower than traditional silicon steel), reducing energy waste and operational costs.

Near-zero magnetostriction minimizes noise and vibration, critical for urban and industrial installations.

​Cold-Rolled Grain-Oriented (CRGO) Silicon Steel:

Laser-cut or step-lapped laminations reduce eddy current losses, achieving efficiency levels up to 99% (IEC 60076 standards).

High magnetic flux density (e.g., 1.9–2.0 T) supports high-voltage applications (up to 400 kV).

​Winding Design​

​Foil Windings with Oil-Flow Cooling:

Copper or aluminum foil windings reduce leakage flux and short-circuit forces. Internal oil channels enhance heat dissipation.

Interleaved layers minimize inter-turn voltage stress, improving short-circuit resilience (up to 50 kA asymmetrical faults).

​Layered Litz Wire Windings:

Multi-strand Litz wire mitigates skin and proximity effects, reducing AC resistance in high-frequency scenarios (e.g., HVDC converters).

​Helical or Disc Windings:

Optimized for high-voltage applications, with graded insulation to withstand lightning impulse voltages (≥1.2/50 μs).

​2. Insulation Systems​

​Oil-Paper Composite Insulation:

Cellulose paper impregnated with mineral oil or ester fluids provides dielectric strength up to 400 kV BIL.

Withstands thermal cycling (−40°C to +140°C) and maintains integrity under partial discharge conditions.

​Epoxy Resin Casting (Dry-Type)​:

Vacuum-pressure impregnation (VPI) with Class H epoxy resins ensures fire resistance (IEC 60335) and moisture tolerance.

​Nano-Enhanced Insulation:

Silica-filled epoxy composites improve partial discharge resistance by 40%, extending lifespan in humid or polluted environments.

​3. Thermal Management​

​Oil-Natural Air-Cooling (ONAN)​:

Passive cooling via radiators and natural oil convection for continuous operation at rated loads (e.g., 100 MVA units).

​Forced Air Cooling (OFAF)​:

Temperature-controlled fans enhance heat dissipation, enabling 120–150% overload capacity for emergency scenarios.

​Oil-Pump-Assisted Cooling (OFWF)​:

Oil circulation pumps and forced-air fans optimize heat transfer for ultra-high-capacity transformers (≥500 MVA).

​Smart Thermal Monitoring:

Fiber-optic sensors and IoT systems track hotspots, triggering alarms or cooling adjustments to prevent insulation degradation.

​4. Structural Design and Protection​

​Robust Tank and Enclosure​

​Corrosion-Resistant Tanks:

Hot-dip galvanized steel or aluminum enclosures with polyurethane/powder coatings resist UV degradation, salt spray, and chemical exposure.

​Hermetic Sealing:

Welded or bolted tanks with EPDM gaskets prevent oil leakage and moisture ingress, ensuring maintenance-free operation for 30+ years.

​Anti-Corrosion Treatment:

Cathodic protection systems and stainless-steel hardware extend lifespan in acidic or coastal environments.

​Safety Features​

​Pressure Relief Valves:

Automatically vent gases during internal faults (e.g., short circuits), preventing catastrophic tank rupture.

​Conservator Tank Systems:

Sealed conservators minimize oxygen contact, reducing oxidation and sludge formation.

​Surge Protection:

Integrated zinc oxide arresters (MOA) and surge capacitors suppress lightning-induced transients (≥2.5 kA lightning impulses).

​5. Advanced Functionalities​

​Condition Monitoring Systems (CMS)​:

Embedded sensors track oil temperature, dissolved gas analysis (DGA), load levels, and partial discharge, enabling predictive maintenance via SCADA.

​On-Load Tap Changers (OLTC)​:

AI-driven tap adjustment optimizes voltage regulation under fluctuating grid loads, reducing energy losses by up to 5%.

​Eco-Friendly Innovations:

Bio-based insulating oils (e.g., ester fluids) with high biodegradability (OECD 301B compliant) and lower flammability.

​Key Applications and Future Trends​

​Grid Transmission:

High-voltage units (220 kV–765 kV) enable long-distance bulk power transfer with minimal losses (<0.5%).

​Renewable Energy Integration:

Support HVDC links for offshore wind farms and grid-scale solar plants.

​Future Advancements:

​Solid-State Transformers (SSTs)​: Enable DC-DC conversion and grid flexibility for decentralized energy systems.

​Self-Healing Insulation: Nanocomposite materials autonomously repair minor dielectric breakdowns.

Summary​

Power Transformers excel through ​low-loss amorphous cores, advanced thermal management, and multi-layered safety systems. Their combination of efficiency, scalability, and resilience makes them indispensable for modern grids, while innovations like ​solid-state technology​ and ​bio-based oils​ drive sustainability and grid intelligence.