Motor Bus Transfer System Performance Testing and the Search for a New Transfer Success Criterion

摘要

The petrochemical industry presently has no industry standards on the performance requirements for relays used to supervise critical process motor bus transfers (MBTs). A device testing protocol is proposed, and the results of extensive performance testing of relays used to implement the fast and in-phase methods of a motor bus synchronous transfer are analyzed. The existing industry criteria for determining the success of a completed transfer are used to evaluate these test results. The development of digital MBT systems with data recording capabilities provided a means of recording transfer data and provides key insight into what happens during actual transfers. Case studies of a number of live MBTs are presented and analyzed to begin to determine if a new transfer metric can be derived, based on recorded transfer inrush current and power when transfer is completed.