Yemen LNG - starter/helper application of VSI + induction motors for 4 LNG compressor lines (2 LNG trains)

Commissioned in 2009/2010, the 4 pieces of equipment (11.5MW/ 3600 rpm) are used for starting the compressors driven by gas turbines. Yemen LNG is one of the first worldwide applications using VSI and induction motors for LNG compressor lines. When the studies were initiated, the usual technology was to use an LCI associated with a synchronous 2-pole turbo motor. In this paper, we intend: A. to compare the two technical solutions: LCI + synchronous motor and VSI + induction motor (footprint, torque pulsations on shaft line, harmonics network, CAPEX/OPEX, etc.) B. to review the results after 18 months of operation C. to present the upgrade project from starter to helper operation for the planned debottlenecking of both LNG trains D. to review/assess the current limits (i.e. power and speed) of this technology and the projected technology developments for the near future.