A dedicated compressor monitoring system employing current signature analysis

The use of motor current signature analysis (CSA) has been established as a useful method for periodic monitoring of electrically driven equipment. CSA is, moreover, especially well suited as the basis for a dedicated continuous monitoring system in an industrial setting. This paper presents just such an application that has been developed and installed in the US government uranium enrichment plant at Portsmouth, Ohio. The system, which is designed to detect specific axial-flow compressor problems in 1700-hp gaseous diffusion compressors, is described in detail along with an explanation of detected fault conditions and the required signal manipulations. Amplitude demodulation and subsequent digital processing of motor signals sensed from area control room ammeter loops are used to accomplish the desired monitoring task. Using modified off-the-shelf multiplexing equipment, a 386-type personal computer, and special digital signal processing hardware, the system is presently configured to monitor ten compressors but is expandable to monitor more than 100. Within its first few days of operation in September 1992, the system detected a compressor problem that, when corrected, resulted in a cost avoidance of about $150,000, which more than paid for the hardware and software development costs. Finally, plans to expand system coverage in the comingmore » year are also discussed.« less