API 546, 4th Edition - Making It Easier to Specify Brushless Synchronous Machines

Ten years have elapsed since the release of the Third Edition of API 546. The standard has been widely applied, but opportunities for improvement have been noted. Over the past five years, the API motors Task Force diligently worked to revise and update the standard, keeping the good and revising the sections that needed clarification. The structure of the standard was also realigned with the latest revision of API 541.This paper highlights some of the key changes to the standard that are introduced in the Fourth Edition. These changes are aimed at improving the quality of synchronous motors and generators (and motor-generators) as well as making them easier to specify. A normative Annex has also been added on super-synchronous high-speed motor applications.