Magnetization and demagnetization circuit design applied to transformer DC dias elimination based on three-phase rectification circuit

摘要

This paper proposes a new approach to eliminate dc bias occurred in transformer based on nanocomposite magnetic material. The dc bias flux in transformer main core can be eliminated directionally using the remanence of the nanocomposite core. According to the material characteristic of the rapid response to an external magnetic field, a magnetization and demagnetization circuit for the nanocomposite was designed based on rectification circuit combined with a capacitor charging circuit. The decaying ac filed used for demagnetizing the material from the ac side can be achieved, while the steady dc field output by rectification circuit can be used for magnetizing the material. The state of the nanocomposite core could be transformed effectively.