S20 oil immersed transformer

　　The S20 oilimmersed transformer is a highefficiency distribution transformer designed for mediumvoltage applications, primarily in power grids, industrial facilities, and commercial buildings. Here’s a detailed breakdown of its key features, specifications, and applications:

　　1. Efficiency and Energy Savings

　　Class Leading Efficiency: The S20 achieves 10% lower noload loss compared to the S13 series and 40% less than S11, meeting China’s GB 200522020 Tier 2 energy efficiency standard . This reduces standby power consumption, making it ideal for grids with fluctuating loads.

　　Core Material: Utilizes 0.18–0.3 mm highgrade grainoriented silicon steel sheets with a 45° stepped lamination design to minimize hysteresis and eddy current losses . Some variants may incorporate amorphous steel cores for even lower noload losses (up to 75% reduction), though this is less common .

　　Load Loss Reduction: Onload losses are 20% lower than S13 and 40% less than S11 due to optimized copper winding designs and vacuumimpregnated insulation .

　　2. Technical Specifications

　　Voltage Ratings: Typically 10/0.4 kV for distribution applications, though models up to 35 kV are available .

　　Power Ratings: Ranges from 125 kVA to 3150 kVA, with some manufacturers offering larger capacities (e.g., 20,000 kVA) for industrial use .

　　Cooling Method: ONAN (Oil Natural Air Natural), where oil circulates naturally and heat dissipates through radiators, ensuring quiet operation and minimal maintenance .

　　Connection Group: Dyn11 as standard, which mitigates harmonic distortion, improves power quality, and enhances shortcircuit withstand capability .

　　3. Design and Construction

　　Core and Windings:

　　Core: Stacked silicon steel sheets with tight tolerances to reduce noise and magnetic flux leakage .

　　Windings: Highpurity oxygenfree copper conductors (enamelled wire for HV, copper foil for LV) enhance thermal conductivity and shortcircuit resistance .

　　Insulation: Vacuum oilimpregnation removes air bubbles, ensuring stable dielectric strength and longevity .

　　Tank Design: Corrugated steel tanks with hermetic seals expand/contract with temperature changes, eliminating the need for a conservator and reducing oil oxidation .

　　4. Environmental and Operational Benefits

　　Noise Reduction: Average noise levels are 20% lower than S13 due to optimized core lamination and winding tensioning, making it suitable for urban and residential areas .

　　Durability: Corrosionresistant tanks and highquality materials ensure a 20+ year lifespan under normal operating conditions (ambient ≤ 40°C, load factor ≤ 80%) .

　　Overload Capability: Can handle shortterm overloads (up to 150% of rated capacity) without compromising insulation integrity, thanks to efficient heat dissipation .

　　5. Applications

　　Power Distribution: Ideal for rural and urban grids, substations, and industrial parks requiring reliable voltage transformation.

　　HarmonicProne Environments: Dyn11 connection and low impedance make it suitable for installations with nonlinear loads (e.g., data centers, factories with variablespeed drives) .

　　Renewable Integration: Supports distributed energy resources (solar, wind) by minimizing losses in decentralized grids.

　　6. Certifications and Compliance

　　Standards: Meets GB 200522020 (China) and aligns with IEC 60076 for voltage, frequency, and insulation requirements .

　　Safety: Designed to withstand lightning impulses and shortcircuit currents per GB/T 1094 and IEC 600765 .

　　7. Cost and ROI

　　Initial Investment: Priced 10–15% higher than S13 but offers faster payback through energy savings. For a 1000 kVA transformer, the annual energy cost reduction can exceed $2,000 compared to S11 .

　　Maintenance: Lowcost routine checks (oil sampling, insulation testing) and fewer component replacements compared to drytype transformers .

　　8. Comparison with Competitors

　　S13 vs. S20: S20 offers better efficiency but at a higher upfront cost. Suitable for projects prioritizing longterm energy savings.

　　DryType Transformers: S20 is more costeffective for outdoor/harsh environments and has lower noise, while dry types excel in indoor, firesensitive settings .

　　9. Manufacturing and Quality Control

　　Materials: Strict sourcing of silicon steel and copper ensures consistency in performance.

　　Testing: Factory tests include partial discharge, temperature rise, and shortcircuit withstand to validate compliance with international standards .

　　In summary, the S20 oilimmersed transformer balances high efficiency, reliability, and costeffectiveness, making it a preferred choice for modern power distribution systems where energy savings and durability are paramount. For specific project requirements, consulting manufacturers for detailed technical datasheets and customization options is recommended.