A Torsional Vibration Problem as Associated With Synchronous Motor Driven Machines

Abstract

Certain component failures in synchronous-driven high-inertia rotating equipment may be traced to a phenomenon peculiar to the starting characteristic of a salient-pole synchronous motor: A synchronous motor contributes a pulsating torque during the starting cycle. Though this fact is well known in itself, it has not been associated with the effect it may have on a high inertia load. The pulsating torque may excite a torsional resonance, which will in turn induce very high stresses in the driven train members.