A new axial magnetic field contact for 126kV single break vacuum interrupters

We proposed a new kind of coil type axial magnetic field (AMF) contact for 126 kV single break vacuum interrupters (VIs). The objective of this paper is to analyze and optimize AMF characteristics of the new contact. Compared with a former coil type AMF contact with 2 segments we developed, the new AMF contact is advantage with stronger AMF and lower electrode resistance. Its AMF characteristics were analyzed by finite element method (FEM) and we optimized AMF characteristics of the new contact by quadratic orthogonal regressive analysis. The optimization design results show that 1) the maximum axial magnetic flux density is 8.84 m T/kA on intermediate plane of contact gap 30 mm at current peak; 2) the maximum axial magnetic flux density is 1.18 m T/kA on intermediate plane of contact gap 30 mm at current zero; 3) the minimum electrode resistance is 7.8 muOmega.