Specifying Adjustable Speed AC Drive Systems and Currently Available Industry Standards

Adjustable speed ac drive systems (ADS) have come to maturity since their introduction over fifteen years ago. It is estimated that over 100,000 units are now in use. At the present time, the available industry standards do not provide sufficient guidance to the user. Most of the currently available standards were developed for uses other than ADS. Also, some proposed standards are being developed but have not progressed as rapidly as originally planned. This paper provides a simplified discussion of the principles of ADS, their different types, and major components. A brief evaluation of the applicability of the available industry standards, particularly to larger ADS, is presented to assist the user. A review of the proposed standards is also presented to keep the user abreast of developments in this area.