Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Protection system of a synchronous motor from an asynchronous mode A.G. NAGIEV, R.A. MELIKOV A principal electrical circuit which is a system of protecting a synchronous engine against asynchronous mode is represented in this article. A transition of the synchronous engine in asynchronous mode when vanishing or “dipping” supply-line voltage is investigated. The suggested system allows protecting an engine from asynchronous mode efficiently Key words: synchronous engine, asynchronous mode, suggested system. Е-mail: mrasim@mail.ru