A New Slot Type Axial Magnetic Field Contact with Low Resistance

This paper introduces a new slot type axial magnetic field (AMF) contact. It has lower resistance compared with its counterpart conventional one by introducing a contact bridge that substitutes for stainless steel support in conventional contact. There is a gap between the contact bridge and contact plate. In close position, the contact bridge is pressed on contact plate by contact force and coil deformation. So current goes through the contact bridge to reach contact plate directly. In an interruption operation, the gap restores with contact force disappearing, which pushes current passing through coils of the slot type AMF contact. So the same AMF can be generated as a conventional one. As a result, short circuit current interruption tests showed that the interrupting capacity of the vacuum interrupter with new contacts was not less than that with conventional contacts. Resistance of vacuum interrupter with conventional contact is 10-12 muOmega at contact force 2000N. It decreased to 7muOmega with the new contact