Synchronizing transients and synchronizers for large machines

IT IS a curious fact that the phenomena encountered in synchronizing operations have received scant attention in the technical literature even though the phenomena have been encountered ever since two synchronous machines were first operated in parallel, and even though a large number of synchronizing operations are performed every day. Possibly the explanation is due to two facts; first, that the ideal conditions introduce no disturbance, and, second, that the synchronizing transients are usually not large but for analysis require consideration as a stability problem of considerable complexity. A review of the synchronizing problem has become desirable because of the development of new types of automatic synchronizers and because of the progress in the analysis of system transients in connection with system stability. This study includes only those synchronizing operations for which the voltage, phase, and frequency conditions are matched before the connection is made; it does not include self-synchronizing methods.