Fast governing of turbogenerators during transients

A mainly theoretical investigation is made of the effects of fast mechanical torque control on the transient stability of turbogenerators. Two aspects of the problem are considered. First the likely improvement in 1st-swing stability is examined, and a method is described of obtaining the stability boundaries in state space for different controls. Secondly, a time optimal-control strategy for reducing subsequent oscillations is examined. It is shown that such a control strategy is unreasonable. A single-machine infinite-busbar system is considered, and experimental results on a model power system are reported.