Parallel operation of A-C generators — Action of governors and Damper windings

SATISFACTORY parallel operation of a-c generators is dependent primarily upon the proper load-speed characteristics of the generators. When driven by reciprocating type prime movers it has been thoroughly investigated and recognized that none of the major torque harmonics of the prime mover should coincide with any of the natural periods of oscillation of the several generators operating in parallel. This paper describes an investigation of the further question of stability of parallel operation when load is suddenly thrown off or on the system, troubles of this sort having been experiences in actual operation.