中文摘要：

大规模的工业生产对透平机械的转子稳定性提出了更高的要求，对稳定性的评价及改善技术的需求极为迫切。采用电磁激振器进行正弦扫频试验，用最小二乘法在频域对转子轴承系统的频响函数进行估计来提高数据精度，并使用均值滤波抑制频响函数的高频噪声使得频响特性更加清晰。再利用变换矩阵，将实数域的传统多输入多输出频响函数转化到复数域直接频响函数来消除正反进动模态叠加的影响，为使用有理多项式法识别转子正进动模态参数提供更高精度数据。采用有理多项式法对传统频响函数和复数域直接频响函数进行拟合识别，得到转子系统的模态参数从而进行稳定性评价，并通过理论计算和试验验证，结果表明该方法准确性较高。该方法可为提高离心压缩机的转子稳定性提供理论和技术基础。

英文摘要：

Higher requirements for the stability of turbomachinery rotors are put forward due to large-scale industrial production, and demands for stability evaluation and modification method becomes extremely urgent as well. The sine-swept vibration excitation experiment with electromagnetic actuator is conducted, and the least square method is used to estimate the frequency response function （FRF） to improve the data accuracy in frequency domain. Additionally, mean filter is used to restrain the high-frequency noise to make the frequency response characteristic clearer. The traditional multiple input multiple output frequency response function （MIMO FRF） is transformed into direct frequency response function （dFRF） from real number field to complex field with a transformation matrix, eliminating the influence of forward and backward modal superposition. The modal parameters are abtained for stability estimation by using the rational polynomial method to fit and identify the traditional MIMO FRF and dFRF on complex field. Get through theory calculation and experimental verification, the results show that this method has enough accuracy.The method can provide both theory basis and technology foundation for improving the rotor stability of the centrifugal compressor.