Blade tip vibration velocity-based monitoring method for compressor surge characteristics

Rotating stall and surge are prevalent phenomena in compressors, with compressor operating conditions typically evaluated through pressure pulsation measurements. Blade tip timing (BTT) technology has been the subject of ongoing research and practical application. To overcome challenges such as complex displacement calculations and signal frequency aliasing, a surge characteristic monitoring approach for compressors based on blade tip vibration velocity is proposed. Blade tip vibration velocity is determined using two small-angle sensors, followed by dynamic recognition through an adaptive Kalman algorithm. The method tracks sub-synchronous frequency variations in blades by analyzing velocity signals and quantifies blade vibration intensity using average velocity. Industrial engineering tests conducted on axial compressors confirm the reliability of the proposed approach. Experimental results show maximum surge amplitudes of 239.71 µm and 242.53 µm identified by velocity-based BTT (V-BTT) and displacement-based BTT (D-BTT), respectively. Surge frequencies detected using the proposed method and Fast Fourier Transform (FFT) are 4.71 Hz and 4.68 Hz, respectively. Compared with conventional techniques, this method reduces frequency aliasing and trend estimation errors while offering advantages for online and real-time surge monitoring.