Patent ID: 7905702

Claim:
A system for correcting rotating stall in a radial diffuser of a compressor, the system comprising: a sensor, the sensor being configured to measure a parameter representative of acoustical energy associated with rotating stall in a radial diffuser of a compressor and generate a sensor signal corresponding to the measured parameter; a first analog circuit including: a first bandpass filter being configured to receive the sensor signal and output a first bandpass filtered signal; a first full wave rectifier being configured to receive the first band pass filtered signal and output a first rectified signal; a first low pass filter being configured to receive the first rectified signal and output a primary stall energy component signal; and a second analog circuit including: a second bandpass filter being configured to receive the sensor signal and output a second bandpass filtered signal; a second full wave rectifier being configured to receive the second bandpass filtered signal and output a second rectified signal; a second low pass filter being configured to receive the second rectified signal and output a secondary stall energy component signal; and control circuitry comprising: a subtractor to subtract the second stall energy component from the primary stall energy component to obtain a differential stall component; and a comparator to compare the differential stall component to a predetermined value to determine rotating stall in the compressor; and; the control circuitry being configured to output a control signal to adjust an operational configuration of the compressor in response to a determination of rotating stall.