METHOD OF IMPROVING TRANSIENT STABILITY OF SYNCHRONOUS MACHINE

摘要

When a fault occurs in an electric power system, a protective relay removes the fault. During this period, an unbalance occurs between the input and output of a synchronous machine and this accelerates or decelerates the synchronous machine. To eliminate this effect within a short period of time and to improve the transient stability of the synchronous machine, it is proposed, during a short period of time following the detection or removal of the fault, to make the direct-current excitation of the synchronous machine stronger than that under the normal operating state. In one form of the method according to the present invention, the so-called automatic voltage regulator is employed, whereby in response to the occurrence or removal of a fault, the excitation of the synchronous machine is increased in such a manner that the terminal voltage of the synchronous machine is made effective as one whose value is apparently smaller than the actual value.