SELECTION, DESIGN AND FIELD TESTING OF A 10,500 HP VARIABLE SPEED INDUCTION MOTOR COMPRESSOR DRIVE by

The cooperative effort is described of equipment manufacturers, the process plant designer and the ultimate user to specify and design a compressor system that was driven by a 10,500 horsepower induction motor that was controlled by a variable frequency drive (VFD) system. A design methodology is presented which avoids the potential of VFD system harmonics from coinciding with system mechanical torsional frequencies. Certain VFD harmonic frequencies that could not be detuned from system torsional frequencies were evaluated for steady state synchronous response. Included are torsional field test data that support the design methodology that was used to avoid torsional resonance and predict torsional system response. Additional test data are presented where the VFD was switched in and out of the system.