Selection and Application of Variable Speed Motor Drive Systems

Several methods of varying speed are available. The considerations to be included in the selection of all-electric drive systems such as eddy current couplings, direct current drives, and ac inverters are presented. The intent is to point out some of the factors which should be considered when evaluating an application, then to incorporate these into the system design. Because each type drive has advantages for each particular application, the relative merits of the individual systems are numerous and are beyond the scope of this presentation.