Motor Current Signal Analysis for Diagnosis of Fault Conditions in Shipboard Equipment

Abstract

ABSTRACTIn the Navy it is imperative that systems and equipment work at their peak performance levels. Man‐hours, money, and even lives may depend on it. On a submarine, it may even be more important, because fault conditions in equipment can lead to increased noise levels, and form a higher probability of detection by the enemy. There are inherent problems associated with detecting fault conditions in shipboard equipment. Most importantly, equipment must often be shut down and taken apart. This can cost countless man‐hours and down time that an underway vessel cannot afford. In addition, the equipment may be located in an area that is very difficult or impossible to reach under normal circumstances. This would include all equipment found in the primary plant of a nuclear powered submarine.Motor current signal analysis provides a solution to these problems. It is a noninvasive technique for monitoring and diagnosing mechanical problems associated with equipment driven by electrical motors. The objective of this project was to implement this process by (1) examining the electrical power signal supplied to a Byron Jackson Sea Water Pump found in a U.S. submarine and (2) to develop signal processing routines and classification techniques to distinguish between the pump working with a good impeller and the pump working with an eroded impeller. Although this one fault condition was studied, this research sought to develop a method by which other fault conditions could be detected.