结合45kW高速永磁同步电动机试验装置及系统,研究了轴承供气压力和升速率对轴系稳定性的影响.针对升速过程中的分岔图、频谱图以及轴心轨迹等特征进行分析,发现高速永磁电动机中存在低频振动的特性.试验结果表明:通过调整轴承供气压力,转子升速的分岔点由18 400r/min推迟到38 900r/min,并消除了38 900r/min以下的半速涡动;改变升速率(升速率由825(r/min)/s变为660(r/min)/s),转子通过临界时工频幅值从95μm降低到75μm. Combined with 45kW high-speed permanent magnet synchronous motor test device and system, the influence of bearing air supply pressure and rising rate on the stability of shafting was studied.According to bifurcation diagram, spectrogram and axis locus in the process of increasing speed, The results show that by adjusting bearing supply pressure, the bifurcation point of rotor speedup is postponed from 18 400r / min to 38 900r / min, and the frequency of 3800r / min is eliminated And the rate of ascending speed was changed from 825 (r / min) / s to 660 (r / min) / s). The rotor frequency decreased from 95μm to 75μm when the rotor passed the critical speed.