Apa itu Transformator Terendam Minyak?

Apa itu Transformator Terendam Minyak?

Sebuahtransformator terendam minyak is a power transformer that usesinsulating oil (minyak mineral atau ester sintetis) for bothpendinginan Danisolasi listrik. Inti dan belitannya terendam minyak, which dissipates heat and prevents electrical breakdown.

Key Components

1. Inti: Laminated silicon steel to reduce eddy current losses.

2. Gulungan: Konduktor tembaga atau aluminium (HV/LV).

3. Tangki: Sealed steel container filled with oil.

4. Insulating Oil:

• Mineral oil (most common).

• Bio-based or synthetic ester (eco-friendly alternatives).

5. Cooling System:

• Radiators/fins (ONAN – Oil Natural Air Natural).

• Fans (ONAF – Oil Natural Air Forced).

6. Protection Devices:

• Relai Buchholz (gas detection for internal faults).

• Pressure relief valve.

• Temperature sensors (oil/winding).

Types of Oil-Immersed Transformers

1. Hermetically Sealed

• Fully sealed tank (no oil exposure to air).

• No conservator; pemeliharaan rendah.

2. Tipe Konservator

• Expansion tank (wali) with breather to absorb moisture.

• Common in large transformers.

3. Step-Lap Core Design

• Reduced no-load losses and noise.

4. Specialty Types:

• Fire-resistant (less-flammable oil).

• Underground (desain kompak).

Keuntungan

✔ Efisiensi Tinggi: Oil provides excellent heat dissipation.
✔ Umur Panjang: Dipelihara dengan baik, lasts 25-30 bertahun-tahun.
✔ Hemat Biaya: Lower initial cost than dry-type transformers.
✔ Kapasitas Kelebihan Beban: Handles temporary overloads better.

Kekurangan

✖ Resiko Kebakaran: Minyak mudah terbakar (requires fireproof barriers).
✖ Pemeliharaan: Regular oil testing and leak checks needed.
✖ Environmental Concerns: Oil disposal and spill risks.

Aplikasi

• Power Distribution: Step-down 11kV/33kV to 400V.

• Industrial Plants: Pabrik baja, chemical factories.

• Energi terbarukan: Wind/solar farm substations.

• Railways: Traction power supply.

Persyaratan Pemeliharaan

1. Oil Testing:

• Dielectric strength (>30 kV for mineral oil).

• Acidity (<0.1 mg KOH/g).

• Moisture content (<20 ppm).

2. Pemeriksaan Kebocoran: Check gaskets, welds, and valves.

3. Penghapusan Lumpur: Clean oil ducts periodically.

Standar & Sertifikasi

• IEC 60076: Standar internasional.

• IEEE C57.12.00: North American standards.

• GB/T 6451: Chinese standards.

Oil-Immersed vs. Transformator Tipe Kering

Purchasing Considerations

1. Kapasitas (kVA): Match to load requirements.

2. Rasio Tegangan: Input/output voltage levels.

3. Impedansi: Typically 4–10% for distribution transformers.

4. Environment: Indoor/outdoor, suhu, kelembaban.

5. Sertifikasi: Ensure compliance with local regulations.

Pertanyaan Umum

Q: Can oil-immersed transformers be used indoors?
A: Ya, but require fireproof vaults and ventilation (NFPA 70 aturan).

Q: How often should oil be tested?
A: Annually for routine checks; after overloads or faults.

Q: Are biodegradable oils reliable?
A: Ya, synthetic esters offer similar performance with lower fire risk.

For acustomized selection, menyediakan:

• Load details (kVA, voltase).

• Lingkungan instalasi.

• Special requirements (misalnya, kebisingan rendah, high efficiency).