A novel approach to transformers design based on acceptability boundary curves of magnetic cores

A novel approach to the design of transformers for switching power supplies is presented. The complete model of the transformer, including thermal properties of core and windings, is solved by means of numerical computation to determine Acceptability Boundary Curves (ABCs). The ABCs allow to identify magnetic cores suitable for the realization of transformers complying with given power handling specifications and with loss, temperature and maximum flux density constraints. The paper shows how to determine windings turns number enabling the use of a certain core. A case study is discussed to prove the efficacy of the ABC concept in practical design.