三峡右岸15～18号发电机振动及噪声优化改进

Improvement and Optimization for Vibration and Noise Performance of No. 15-18 Power Generating Unit of Three Gorges Right Bank Power Plant

针对三峡右岸15～18号发电机及左岸VGS发电机投运后振动和噪声偏大现象,进行了全面系统的测试及理论分析。发现发电机电磁方案存在设计缺陷,是引起100Hz电磁振动和噪声的内在根源,定转子不圆(气隙不均匀)是引起发电机1～3倍转频振动的主要原因,同时认识到了结构及安装精度对机组的振动摆度会产生较大影响。通过更改发电机定子接线方式解决了100Hz电磁振动和噪声问题,控制安装质量和改进发电机部分结构等措施大幅降低了发电机1～3倍转频的低频振动幅值和混频幅值,从根本上解决了上述发电机振动和噪声问题。

A comprehensive and systematic testing and theoretical analysis were carded out on the abnormal vibration and noise level of generating Unit 15-18 at Right Bank Power Plant and 6 generators supplied by VGS Consortium for the Left Bank Power Plant. It was found that the electromagnetic design was the inherent cause for 100Hz electromagnetic vibration and noise, while the roundness deviations of both stator and rotor （uneven air gap） are the major reason to cause vibration of generators with 1-3 multiple rotating frequency. It was also found that the mechanical structure and installation accuracy of the units also produce rather impact on unit vibration and run-out. By changing the generator stator connections, the 100Hz electromagnetic vibration and noise were completely eliminated, while by controlling the installation quality and improving generator mechanical structure, the 1-3 multiple rotating frequency vibration amplitude and mixed-frequency amplitude were significantly reduced. Consequently, the above-mentioned abnormal vibration and noise of generators were basically resolved.