Analysis and design of current transformers for low-frequency transmission systems using hybrid magnetic materials

In low-frequency transmission, traditional current transformers face the problem of saturation distortion issues, while utilizing materials with high magnetic saturation intensity could add measurement errors. In order to solve this problem, the mixed materials current transformer (MMCT) is proposed, which uses two cores, one made of conventional silicon steel with an air gap and the other made of nanocrystalline alloy material without an air gap. Theoretical analyses and finite element method simulations are carried out to validate the practicability and effectiveness of the proposed MMCT. Furthermore, the performance is optimized to address the effect of the air gap. The results manifest that the transmission characteristics of the MMCT are outstanding.