AC Drives and Soft Starter Application Guide

摘要

There are usually several choices for starting motors. Two of these, ac variable frequency drives (VFD's) and soft starters, seem to have similar characteristics. Terms and descriptions used in product literature are nearly the same. Even the list of possible applications is similar. However, the technology and performance are significantly different. When these differences are understood, it becomes clear when and where to properly apply each of them. The objective of this paper is to provide the basic technical information to understand the differences. First covered are the operating principles of the VFD and soft starter. How motor performance is affected is the other key to selection of the proper starting method. Finally, guidelines will then be presented.