Method for detecting rotating stall in a centrifugal compressor

The invention provides a system and method for detecting rotating stall in a centrifugal compressor, which comprises following steps: detecting the value of the acoustic energy associated with the onset of rotating stall in the centrifugal compressor; performing a fast Fourier transform (FFT) based on the detected value to obtain a plurality of frequency and corresponding energy value; selecting the frequency and energy value associated with the rotating stall from the plural frequency and corresponding energy value; summing the corresponding energy value of the selected frequency associated with the rotating stall; comparing the summing energy value and the preset critical value to determine the rotating stall in the centrifugal compressor, in which when the summing energy value is largerthan the critical value, the rotating stall occurs in the centrifugal compressor.