+86 18068001229
01
Durable Oil-Immersed Three-Phase Grid Systems
Core Features & Benefits
Efficient Cooling & Durability
Immersed in high-quality insulating oil, the transformer dissipates heat effectively (ONAN/ONAF cooling), maintaining optimal performance even under heavy loads. The oil also acts as an insulator, enhancing electrical safety and reducing wear.
High Reliability & Low Maintenance
Robust construction with copper windings and advanced paper-oil insulation systems ensures resistance to thermal stress, moisture, and short circuits. Minimal maintenance requirements make it ideal for remote or hard-to-access locations.
Compact & Modular Design
Available in voltage ratings from 11kV to 33kV and capacities up to 5 MVA, with single or three-phase configurations. Compact sizing simplifies installation in urban substations, industrial parks, or rural networks.
Smart Monitoring (Optional)
IoT-enabled sensors (optional) provide real-time data on oil temperature, load levels, and fault detection, enabling predictive maintenance and reducing downtime.
Eco-Friendly & Cost-Effective
Low noise operation (<70 dB) and recyclable materials align with environmental regulations. High energy efficiency (IEC 61378 compliant) minimizes power losses and operational costs.
Applications
Residential Networks: Stepping down medium voltage (11kV/33kV) to 230/400V for households.
Industrial & Commercial: Stable power supply for manufacturing plants, data centers, and shopping malls.
Renewable Integration: Connecting solar/wind farms to low-voltage grids.
Rural Electrification: Durable design for remote or harsh environments.
Technical Specifications
Voltage Range: 11kV to 33kV (medium voltage).
Capacity: 500 kVA to 5,000 kVA.
Frequency: 50Hz/60Hz.
Cooling: ONAN (Oil Natural Air Natural) or ONAF (Oil Natural Air Forced).
Efficiency: ≥98% at full load (IEC 61378 certified).
Quality Assurance
Rigorous testing ensures compliance with global standards:
Dielectric strength tests for insulation integrity.
Load loss and temperature rise measurements.
Short-circuit withstand verification.
Certified by ISO 9001 (quality), ISO 14001 (environment), and KEMA for safety and reliability.
Why Choose Us?
30+ Years of Expertise: Proven designs for diverse climatic and operational conditions.
Global Support Network: Localized service teams and 24/7 technical assistance.
Competitive Pricing: Scalable solutions tailored to budget and performance needs.
Custom Solutions
Specialized Designs: For extreme temperatures, corrosive environments, or seismic zones.
Energy Efficiency Upgrades: Retrofit kits for legacy systems.
Product advantages
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.
High permeability and near-zero magnetostriction minimize noise and vibration, ideal for residential and industrial zones.
Cold-Rolled Grain-Oriented (CRGO) Silicon Steel:
Laser-cut or step-lapped laminations reduce eddy current losses, achieving efficiency levels up to 98.5%.
Optimized grain orientation enhances magnetic flux density for high-voltage applications (e.g., 11kV–33kV).
Winding Design
Foil Windings with Oil-Flow Cooling:
Copper or aluminum foil windings reduce leakage flux and short-circuit forces. Oil circulation through winding ducts enhances heat dissipation.
Interleaved conductor layers minimize inter-turn voltage stress and improve short-circuit resilience.
Layered Litz Wire Windings:
Multi-strand Litz wire mitigates skin and proximity effects, reducing AC resistance and losses in high-frequency scenarios.
Compact Three-Limb Core Configuration:
Symmetrical design balances magnetic flux, minimizing zero-sequence losses and improving thermal uniformity.
2. Insulation Systems
Oil-Paper Composite Insulation:
High-quality cellulose paper impregnated with insulating oil (e.g., naphthenic or paraffinic mineral oil) provides dielectric strength up to 300 kV BIL.
Combines thermal stability (withstands temperatures up to 140°C) and fire resistance.
Epoxy Resin Coating (Dry-Type Hybrid):
Partial discharge-resistant epoxy resin for coil encapsulation, enhancing moisture and pollution resistance.
Nano-Enhanced Insulation:
Silica-filled epoxy composites improve partial discharge lifetime by 30–50%, ideal for coastal or industrial environments.
3. Thermal Management
Oil-Natural Air-Cooling (ONAN):
Passive cooling via radiators and natural oil convection, suitable for continuous operation at rated loads.
Forced Air Cooling (OFAF):
Temperature-controlled fans enhance heat dissipation, enabling 120% overload capacity for short durations.
Oil-Pump-Assisted Cooling (OFWF):
Oil circulation pumps and forced-air fans optimize heat transfer for high-density urban substations.
Smart Thermal Monitoring:
Embedded temperature sensors and IoT-enabled systems trigger alarms, load shedding, or cooling activation 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 decades.
Anti-Corrosion Treatment:
Cathodic protection systems and corrosion-resistant coatings extend lifespan in acidic or humid climates.
Safety Features
Pressure Relief Valves:
Automatically vent gases during internal faults (e.g., short circuits), preventing tank rupture.
Oil Preservation System:
Conservator tanks or sealed conservators minimize oxygen contact, reducing oxidation and sludge formation.
Surge Protection:
Integrated zinc oxide arresters (MOA) and surge capacitors suppress lightning-induced transients.
5. Advanced Functionalities
Condition Monitoring Systems (CMS):
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 and lower flammability, aligning with IEC 62721 standards.
Key Applications and Future Trends
Industrial and Urban Distribution:
High-capacity units (500kVA–5MVA) power factories, commercial complexes, and smart cities.
Renewable Energy Integration:
Ideal for wind/solar farm substations and microgrids, supporting bidirectional power flow.
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 defects.
Summary
Three-Phase Oil-Immersed Distribution 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 power grids, while innovations like bio-based oils and smart
Inquire Now!
For inquiries about our products or pricelist, please leave your email to us and we will be in touch within 24 hours.