Revamping A Gas Compressor Drive Train From 7000 To 8000 HP With A New Synchronous Motor Driver And A Controlled Slip Clutch Mechanism.

The successful application of synchronous motors requires special design consideration to account for their speed-dependent characteristics, such as the large oscillating torque levels that occur during startup. This paper focuses on the torsional design and analysis process associated with revamping a 7000 hp synchronous motor-driven compressor train with an 8000 hp synchronous motor driver. Torsional analyses indicated that the replacement motor’s startup torque would produce unacceptable levels of torsional vibration. An accurate overtorque protection slip clutch was integrated into the low-speed coupling assembly to limit startup peak torque to about three times the normal operating torques. The paper details multiple issues associated with revamping the compressor drive train, including the selection of the replacement driver and low-speed coupling assembly, torsional vibration analysis, and the mechanical operation of the controlled slip clutch mechanism. The paper also presents the acquired torsional field measurements that were used to confirm the clutch’s operation. 33 REVAMPING A GAS COMPRESSOR DRIVE TRAIN FROM 7000 TO 8000 HP WITH A NEW SYNCHRONOUS MOTOR DRIVER AND A CONTROLLED SLIP CLUTCH MECHANISM