Abstract: As an improved way of effecting fast valving of turbines of power system steam-electric installations of types that incorporate by-pass systems for by-passing steam from a point ahead of the high pressure turbine either directly to the condenser or to the cold reheat line, and in the latter case also from the hot reheat line to the condenser, and where the purpose of employment of fast valving is to improve the stability of power transmission over transmission circuits to which the generators of the installations in question make connection, when stability is threatened by line faults and certain other stability endangering events, the approach of rapidly closing intercept valves at fastest available closing speed in response to a fast valving signal, is supplemented by bringing into effect preprogrammed processes of control valve repositioning, plus intercept valve reopening, so effected as to cause turbine driving power subsequent to generator rotor first forward swing to hold below a preset value that is l

Abstract: As a improved way of effecting fast valving of turbines of power system steam-electric generating units for the purpose of improving the stability of power transmission over transmission circuits to which their generators make connection, when stability is threatened by line faults and certain other stability endangering events, the heretofore employed and/or advocated practice of automatically closing intercept valves at fastest available closing speed in response to a fast valving signal, and thereafter automatically fully reopening them in a matter of seconds, is modified by providing to reopen the valves only partially to and thereafter retain them at a preset partially open position.For best results the process of what can be termed sustained partial reopening is so effected as to result in its completion within a fraction of a second following the peak of the first forward swing of the generator rotor.

Abstract: As a improved way of effecting fast valving of turbines of power system steam-electric generating units for the purpose of improving the stability of power transmission over transmission circuits to which their generators make connection, when stability is threatened by line faults and certain other stability endangering events, the heretofore employed and/or advocated practice of automatically closing intercept valves at fastest available closing speed in response to a fast valving signal, and thereafter automatically fully reopening them in a matter of seconds, is modified by providing to reopen the valves only partially to and thereafter retain them at a preset partially open position.For best results the process of what can be termed sustained partial reopening is so effected as to result in its completion within a fraction of a second following the peak of the first forward swing of the generator rotor.