Choosing electric turbocompressor drivers

High-speed electric motor variable speed drives used to drive centrifugal compressors of any size are proven technology, and the examples shown in this paper are exemplary for many other successful inscallations. Economics will not always justify their use, particularly if there is no reliable and economical source of electric power available at site, but most applications can ill-afford not to evaluate them. There are a number of success factors in the proper design and use of very large VSD systems that will make such systems a success: thoroughly match the compressor's torque-speed envelope with available drive designs; consider all system components combined-their characteristics and capabilities must be carefully matched; close cooperation of the compressor and motor manufacturer is of paramount importance; vibration and harmonic analyses prior to manufacturing are mandatory and may have consequences on the final electrical and mechanical design; and an integrated and coordinated protection and control system increases system transparency and reliability.