Applicability of API 617 8th ed. and ISO 14839-3 in Evaluating the Dynamic Stability of AMB-supported Compressors

Oil & Gas (O&G) original equipment manufacturers (OEMs) have long used API 617 as the international standard of choice to guide turbomachinery rotordynamics requirements. Recently, the O&G industry has experienced a growing interest in applying active magnetic bearings (AMB) in high-speed applications, hermetically-sealed applications, and compressors with a large performance envelope. As such, the API 617 standards have recently been expanded to include a section (API 617, 8th ed., “Annex E”) regarding evaluation of magnetic-bearing-supported compressors. New standards included in Annex E both compliment and compromise existing, well-regarded international magnetic bearing rotordynamics standards, namely ISO 14839-3. This paper reviews and compares the dynamics requirements included in API 617 8th edition Annex E with those of ISO 14839-3. Notable, this paper compares the stability criteria of both standards by simulating the synchronous response, sensitivity transfer function, and closed-loop transfer function of simple 1-D dynamic systems.