Trafo

Trafo (Transformator) – Comprehensive Guide

1. Main Types of Trafo

(1) By Cooling Method

• Oil-Immersed Trafo

• Uses insulating oil for cooling, suitable for high-voltage and high-capacity applications (z.B., grid substations).

• Common Models: ONAN (natural cooling), AN OFF (forced air cooling), OFAF (forced oil and air cooling).

• Dry-Type Trafo

• Oil-free design, insulated by air or resin, ideal for fire-sensitive environments (z.B., Spideeler, Daten Zentren).

• Common Models: SCB (epoxy resin-cast), SG (open-type).

(2) By Application

• Distribution Trafo

• Voltage levels: 10kV/0.4kV, used for end-user power supply (z.B., residential areas, Fabriken).

• Power Trafo

• Voltage levels ≥110kV, used in transmission networks (z.B., substation main transformers).

• Special Trafo

• Includes rectifier transformers (for electrolysis), mining transformers (explosion-proof design), etc.

                     

2. Key Specifications

3. Uwendungen

• Power Systems: Voltage step-up/down, grid interconnection.

• Industriell: Power supply for motors, Uewen (custom impedance may be required).

• Erneierbar Energie: PV/wind grid integration (must withstand harmonics).

• Rail Transit: Traction transformers (25kV/50Hz).

4. Selection Guide

• Indoor Installation: Prefer dry-type (fireproof) or fully sealed oil-immersed.

• Outdoor Installation: Oil-immersed (protection class ≥IP55).

• High Load Fluctuations: Choose models with strong overload capacity (z.B., ONAF cooling).

•                  

5. FAQ

Q: How to choose between oil-immersed and dry-type transformers?
A: Oil-immersed offers lower cost and higher capacity but requires fire protection; dry-type is safer for confined spaces.

Q: How to calculate required capacity?
A: Sum all load power (kVA) and reserve 20%~30% margin.

Q: How to reduce transformer noise?
A: Select low-noise designs (z.B., step-lap core) or install soundproof enclosures.