Modernization of legacy adjustable speed drives brings new life to high capacity systems

A method of modernization of existing adjustable speed drives is discussed in this paper. It provides the philosophy and the decision making tools needed on performing a drive upgrade to installed old drives, from a drive manufacture´s perspective. Also, this paper provides a blueprint for the end users on evaluating the various retrofit/replacement options available. End user benefits and a comprehensive site survey are presented reinforcing the concept of a drive modernization. The modernizations whether on a direct current paper mill drive or a large pipeline compressor drive, have given new life to the adjustable speed drive while saving the operator thousands, perhaps millions of dollars in capital expenditures to maintain or replace the adjustable speed drive. The conclusion of this paper is that manufacturers and operators have a new options to explore that eliminates the concern of the adjustable speed drive being expensive to maintain or even obsolete after 15 to 20 years of operation.