Analysis of Strap Losses for High Power High Frequency Inductors

This paper presents a detailed analysis to evaluate the performance changes of high power, high frequency inductor with the existence of mounting strap. 2D finite element analysis (FEA) is used thoroughly for the losses calculations of the strap in terms of materials, air gap distance, and mounting strap thickness. After that, an optimal way of selecting the mounting strap material, strap thickness and air gap distance is derived. Then, a simplified equation is created to predict the strap losses and verified by a 2-D FEA simulation. Later on, the existence of the mounting strap to inductance calculation, coil losses and core losses are studied. Dramatic changes can be found on these performances for an inductor with mounting strap. Finally, some guidelines of using the mounting strap in high frequency high power inductors are proposed in the end of the paper.