ROTATING STALL DETECTION THROUGH RATIOMETRIC MEASURE OF THE SUB-SYNCHRONOUS BAND SPECTRUM

摘要

A method for obtaining a baseline for detecting rotating stall using localized information already included within the frequency spectrum. Namely, ratiometric measures, i.e., quadratic coefficients obtained from weighted quadratic regression of sub-synchronous spectrum and/or information obtained through peak detections, are used to detect rotating stall. These ratiometric measures are configured to isolate changes caused by rotating stall from those caused by other operational conditions. As a result, new baseline information can be established to more reliably characterize a system, such as a system with associated turbines or compressors. Empirical or statistical approaches can be combined to automate the process of obtaining a new baseline and to detect rotating stall.

主权项

1. A method comprising:
calculating, by a computer based system configured to detect rotating stall, a power spectrum density (PSD) from data collected for a signal in the time domain; determining, by the computer based system, a synchronous frequency component from at least one of the signal or an external signal source; identifying, by the computer based system, a frequency band from the calculated PSD and the determined synchronous frequency component as a sub-synchronous spectrum band; calculating, by the computer based system, a quadratic function approximation coefficient to the identified frequency band in the identified sub-synchronous spectrum band; setting, by the computer based system, a calculated quadratic function approximation coefficient to zero if at least one of the calculated quadratic function approximation coefficient is a positive number and the peak of the calculated quadratic function approximation is located outside the identified sub-synchronous spectrum band; and analyzing, by the computer based system, the quadratic function approximation coefficient as an indicator of rotating stall for at least one of a baseline and detection.