Leliuk M. Improvement of vacuum contactors with monostable polarized electromagnets

The dissertation is devoted to the improvement of medium voltage vacuum contactors with monostable polarized electromagnets, in particular, to reduce the bounce of main contacts, which is one of the main requirements for these apparatus. The concept of contactors with bistable actuators on the basis of monostable polarized electromagnets with rotary springs is proposed and implemented. The mathematical model of contact welding is improved at their bounce. The mathematical model of the process of switching on the contactor is improved and calculations of the dynamic characteristics of the electromagnet are carried out. Experimental investigations of a monostable polarized electromagnet are carried out. The concept of constructing a microprocessor hybrid control system for monostable polarized electromagnets based on the use of an interface relay with two switching contact groups and one power transistor is proposed and implemented. The microprocessor hybrid control system operation algorithm is developed and the minimum interval between the switching points of the interface relay and the IGBT transistor is established. A prototype of a new universal vacuum contactor is developed. It is established that the operation of the contactor by the position sensor decreases the total time of switching on and switching off the contactor. Key words: electrical apparatus, improvement, commutation, design methods, vacuum contactor, vacuum interrupter, microprocessor control system, interface relay.