An electromagnetic actuator for the medium voltage vacuum contactor

Abstract

A review of the use of mono- and bistable unpolarized and polarized electromagnets in medium voltage contactors is presented. The analysis of the design features of electromagnetic actuators is carried out and recommendations for their improvement are developed. A new design of a bistable actuator based on a polarized monostable electromagnet with a return spring, its principle of operation are considered. Due to the use of a ring-shaped element of a non-magnetic material between the case and the core of the electromagnet, it is possible to reduce the effect of shunting without increasing the axial size of the electromagnet. For the prototype, the magnetic fields are calculated in the off position, with a gap of 12 mm between the armature and the fixed part of the magnetic core and in the on position, with the armature pressed. The effect of a ring ferromagnetic shunt on the traction force at the released and pressed armature is determined. The electromechanical control system of a single-coil bistable actuator is developed. Experimental investigations of a bistable actuator based on a polarized monostable electromagnet with a return spring are carried out. The time for switching on and off of the new vacuum contactor is set.