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)