The paper considers the detailed operation of a typical steam-turbine governor of the form widely used in conjunction with synchronous generators connected to large power systems.The role played by the prime-mover governor in the transient performance of the synchronous generator is not yet fully elucidated. The research team at the University of Newcastle upon Tyne has been studying governor effects by computer techniques, and the simulation described is associated with this work.It was regarded as essential to express the governor performance under conditions of transient disturbance of the power system with accuracy, although it was also necessary to have a representation that was simple relative to that of the power system and electrical generator. The paper develops and justifies alternative transfer-function representations of the governor system for the problem defined.