Analysis of designs of drive mechanisms of medium voltage vacuum contactors

Abstract

One of the main elements of medium voltage vacuum contactors is the drive mechanism, which includes an electromagnet. In existing models of contactors, two types of electromagnets are used: monostable non-polarized electromagnets with a return spring or bistable polarized without a return spring. It was found that the use of polarized electromagnets in combination with a microprocessor control system expands the functionality of the contactor and makes it possible to reduce the energy consumption of the electromagnets, their overall dimensions and weight, while achieving significant armature holding forces. The designs of polarized electromagnets, which were developed at the Department of Electrical Apparatus in recent years, are considered. Their shortcomings were identified and a new design of a bistable polarized electromagnet was proposed, a computer model of the contactor developed in the KOMPAS-3D package was built. The counteracting characteristic of the mechanical system of the contactor, which is brought to the axis of the electromagnet and the stroke of the armature, is constructed, the forces that must be created by the electromagnet in the on and off position for reliable operation are determined. The FEMM model of the experimental sample of a bistable polarized electromagnet was developed and the calculation was carried out in the on and off positions. The possibility of using a new design of an electromagnet in a medium-voltage vacuum contactor has been confirmed.