METHOD TO SYNCHRONISE EXCITED SYNCHRONOUS GENERATOR WITH GRID Russian patent published in 2013 - IPC H02J3/40 

FIELD: electricity.

SUBSTANCE: according to the method, the moment of generator connection to the grid is determined in process of its acceleration under action of a driving engine. Excitation of the generator is set in such a manner that voltage of the generator under synchronous speed of rotation is equal to the grid voltage. As the generator accelerates, voltage at the generator's anchor winding increases proportionately to the speed of rotation and is continuously compared with the grid voltage. Since frequencies and amplitudes of the grid and the generator are not identical, difference of instantaneous values of generator and grid voltages (beat voltage) varies from maximum to minimum voltages. The generator is connected to the grid whilst approaching the rated speed of rotation at the moment when the minimum of the beat voltage becomes less or equal to 10% of the generator rated voltage, which indicates approaching of generator and grid phase voltages.

EFFECT: increased efficiency of synchronous generator connection to the grid with low surge current.

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