Failure Analysis of Induction Motors: Magnetic Wedges in Compression Stations

This article presents the failure analysis and field measurements of five 7,500-hp induction motors driving reciprocating compressors for a natural gas compression station. The failure analysis examined fan design, vibration, motor-operating temperature, compressor loading profile, number of motor starts, and ambient temperature. A comparison between direct online motor starting and soft starting using an adjustable speed drive (ASD) and the impact on motor performance are presented. The settings and historical data gathered from the microprocessor protection relay for the motors are also covered and discussed.