ANALYTICAL APPROACH TO THE OPERATION OF A SYNCHRONOUS MACHINE ASSOCIATED WITH A THYRISTOR BRIDGE

Abstract

A synchronous machine associated with a thyristor bridge operates normally under unbalanced conditions which are described and studied in the present paper. Natural cut-off thyristors is used in the present system where the gates of thyristors are controlled by the rotor position. It is assumed that the machine has salient poles and damper windings. Both motor and generator operations are contemplated. An analytical approach has been used, and the exact shape of the currents has been considered. The commutation problem is studied in detail, taking into consideration the transient effects of the armature circuits and the limited value of the smoothing reactor. The different expressions are given in terms of the classical machine constants which can be directly measured or furnished by the manufacturer. Comparison between theoretical and practical results are given.