Key Features of Oil-Immersed Distribution Transformers

Key Features of Oil-Immersed Distribution Transformers

Anoil-immersed distribution transformer is a type of electrical transformer that uses insulating oil as both a coolant and dielectric medium. These transformers are widely used in power distribution networks to step down voltage levels (typically from 11kV/33kV to 415V/240V) for industrial, 광고, 주거용 애플리케이션.

1. Cooling& Insulation

• Mineral oil or synthetic ester oil is used to dissipate heat and provide electrical insulation.

• The oil also prevents oxidation and moisture absorption, extending transformer life.

2. Construction

• 핵심: Made of laminated silicon steel to reduce eddy current losses.

• 권선: Copper or aluminum conductors (HV & LV windings).

• Tank: Sealed or conservator-type (with a breather to prevent moisture ingress).

• 부싱: Porcelain or polymer insulators for cable connections.

• Radiators/Fins: Enhance cooling by increasing surface area.

3. 유형

• Hermetically Sealed: Fully sealed to prevent oil oxidation (no conservator).

• Conservator-Type: Uses an oil expansion tank (관리자)       with a breather.

• 오난 (오일 천연 공기 천연): Passive cooling (natural oil & air circulation).

• 켜짐 꺼짐 (오일 천연 에어 강제): Fans are added for better cooling at higher loads.

4. 장점

• Efficient heat dissipation, allowing higher load capacity.

• 긴 서비스 수명 (20-30 years with proper maintenance).

• Reliable performance in varied environmental conditions.

• Lower initial cost compared to dry-type transformers.

5. 단점

• Fire risk due to flammable oil (requires fire safety measures).

• Regular maintenance needed (oil testing, leakage checks).

• Environmental concerns (oil disposal, potential spills).

6. 응용

• Power distribution networks (utility substations).

• 산업 플랜트, 상업용 건물, and residential complexes.

• 재생 에너지 시스템 (solar/wind farms).

Maintenance Requirements

• Oil Testing: Check dielectric strength, moisture content, and acidity.

• Leak Inspection: Ensure no oil seepage from gaskets or welds.

• Bushing & Winding Checks: Detect insulation degradation.

• Sludge Removal: Prevent clogging in cooling ducts.

표준 & Certifications

• IEC 60076 (International standards for power transformers).

• IEEE C57.12.00 (General requirements for liquid-immersed transformers).

• IS 1180 (Indian Standard for oil-immersed distribution transformers).

Comparison with Dry-Type Transformers

결론

Oil-immersed distribution transformers are cost-effective and efficient for medium-to-high power distribution but require careful handling due to oil-related risks. They remain the preferred choice for outdoor and high-load applications where cooling efficiency is critical.