Estimation Performance Analysis Of Energy Centrobaric Correction Method And Its Application In Vibration Testing

The estimation signal parameters from Fast Fourier Transform (FFT) normally deviate from the real values, which have greatly limited the applicability of discrete spectrum analysis technology. Discrete spectrum correction technology has been proposed to reduce the estimation error and obtain precise signal parameters, such as frequency, amplitude and phase, which can make a contribution to broaden application range of discrete spectrum technology.The Energy Centrobaric Correction Method is a universal discrete spectrum correction method and has high estimation accuracy. This paper investigates estimation error of Energy Centrobaric Correction Method for discrete spectrum without noise influence, and then investigates the noise influence on the estimation performance of Energy Centrobaric Correction Method for discrete spectrum. The theoretical estimation errors of frequency, amplitude and phase have been derived under condition that the observed signal is multiplied by a symmetrical window function. Simulations for discrete spectrum are carried out to verify the correctness of theoretical derivation. The reasons for large error generated under some condition have been analyzed, and measures that using 3+4 spectrum lines for frequency and phase correction and 4 spectrum lines for amplitude correction have been proposed to overcome the drawbacks of Energy Centrobaric Correction Method, Simulations results also demonstrate that the improved Energy Centrobaric Correction Method has higher anti-noise performance and broader application range.Applying Energy Centrobaric Correction Method in vibration testing and analysis can improve the analyzing accuracy and reliability, which have been verified through engineering applications in last part in this paper, such as rotor balancing, engine torsional vibration analysis and wind generator fault diagnosis. The results demonstrate that Energy Centrobaric Correction Method can provide a powerful analytical tool for vibration testing and analysis in engineering application.