Evaluate qualitatively the limitations of the ideal transformer model and the strategies used to improve transformer efficiency

Evaluate qualitatively the limitations of the ideal transformer model and the strategies used to improve transformer efficiency

Incomplete flux linkage

  • Magnetic field can always be detected near transformers, which means the magnetic field created by the primary coil doesn’t pass through the secondary coil completely.
  • strategies used to reduce flux leakage are:
    • a core of soft iron which can be easily magnetised.
    • the winding design is changed. For example the secondary coil is wound over the primary coil.

Resistive heat production and eddy currents

  • the coils heat up due to resistance. Thus energy is lost as heat.
  • the changing magnetic field passing through the iron core creates eddy currents
  • Strategies adopted to combat these problems include:
    • The iron core is constructed with multiple layers of iron which are coated with insulators.
    • use ferrites as cores.

 

Extract from Physics Stage 6 Syllabus © 2017 NSW Education Standards Authority (NESA)