| Abstract |
Inductors are usually realized with E, I cores and C core types. Some other construction types are also possible, using a combination of I cores and ring cores and cut ring cores. We designate them as OI, CIC, 4I and 6I (hexagonal) cores. We compare their weight for a given copper loss and a given reactive power. Although ring cores with multiple air gap seem the best solution, the optimal inner/outer diameter ratio is much lower than usual, and high copper filling factors are not realistic. The CIC-inductor has also a good performance and uses oriented steel more efficient than in EI-cores, but has no improved heat transfer compared to EI-shapes. The hexagonal inductor type combines a high peak induction, a high filling factor and a good heat transfer to ambient and reduces weight and losses for inductors. To check the design a hexagonal core was constructed. However a drawback might be the tendency to mechanical vibration. Some of the core types may also be useful in ferrite cores. |
