Design and selection of High frequency Transformer

ABSTRACT The fundamental requirements of magnetic material for power transformers is the highest relative permeability, the largest saturation flux density, the lowest core loss and the lowest remnant flux density. Magnetic materials used as the core of power transformers keeps changing as the operating frequency changes (increased/decreased). At the line frequency of 50/60 Hz, iron, low-silicon iron and silicon steel are the major materials applicable for the design of cores of the power transformers. They have high saturation flux density, thus they can handle high power transformation at low operating frequency also. When the operating frequency of power transformer increased, the eddy current inside the magnetic cores becomes a critical problem for the transformer designers. Although the laminated core materials have been used, the power loss generated by the eddy currents still heat up the core and this hot spot generated inside magnetic core can destroy whole power transformer. Nowadays, Ferrite used is ceramic materials dark gray or black colored in appearance and very hard composite. General magnetic properties of the ferrite are as permeability of several tens, very high resistivity, Low coercive force and better heat dissipation. KEYWORDS: Ferrite,Permeability,efficiency,ceramic,coercive