(8) Energy Loses in Transformer (Flux Leakage, Hysteresis Loss, Eddy Current Loss, Coper Loss) BEE

Unit Three: Transformers

Energy Losses in Transformers

• Transformers are devices used to transfer electrical energy between circuits.

• Four primary types of energy losses in transformers:

  • Flux leakage

  • Resistance of winding

  • Hysteresis loss

  • Eddy current loss

Transformer Construction

• Key Components:

  • Core: Made of ferromagnetic material (e.g., soft iron).

  • Primary Winding: Copper wire where power input is provided.

  • Secondary Winding: Copper wire where power output is received.

• Example Power Transfer:

  • Input: 100 kilowatts to primary winding.

  • Output: 95 kilowatts to secondary winding due to losses.

1. Flux Leakage

• Definition: Loss of magnetic flux that does not link with the secondary winding.

• Explanation:

  • When AC current is supplied to the primary winding, it generates changing magnetic field lines.

  • Only about 80% of the generated flux is transferred to the secondary winding, leading to a 20% loss of energy.

• Mitigation:

  • Use of ferromagnetic materials (e.g., soft iron) reduces flux leakage.

2. Energy Loss Due to Resistance of Winding

• Explanation:

  • Energy is lost due to the resistance of copper winding.

  • Loss occurs as heat, calculated using the formula I²RT.

• To minimize resistance:

  • Increase Cross-Sectional Area: Thicker wires reduce resistance.

  • Application in Transformers:

    • Step-Up Transformer: Thicker wire used on the primary side (high current).

    • Step-Down Transformer: Thicker wire used on the secondary side (high current).

3. Hysteresis Loss

• Definition: Loss due to cycles of magnetization and demagnetization in core material under alternating current.

• Explanation:

  • Changing magnetic field leads to energy loss from the hysteresis effect.

• Mitigation:

  • Using soft iron minimizes hysteresis loss compared to steel.

  • Hysteresis loss is represented graphically, with the area enclosed indicating the loss.

4. Eddy Current Loss

• Definition: Circulating currents induced within the core material due to changing magnetic fields.

• Explanation:

  • Eddy currents form loop patterns within the core, leading to heat losses calculated as I_e²RT.

• Mitigation:

  • Laminated Cores: Using thin plates insulated from one another reduces eddy currents.

    • This limits the currents to only the surface area of each laminated plate, minimizing heat loss.

Conclusion

• Understanding these energy losses is crucial for optimizing transformer design for better efficiency.

• Focus on minimizing these losses to allow maximum power transfer.