600 MW发电机转子不稳定振动分析及控制

某电厂600 MW氢冷发电机转子自投产后,发电机轴承振动、轴振动随负荷增加而大幅度增加。通过有功负荷变化试验、转子电流变化试验和氢气温度变化试验发现,其主要原因是发电机转子制造工艺欠佳,热态下部件膨胀变形后在端部产生了新的质量不平衡,造成三阶振型,引起振动增加。在计算转子热变形的振动幅值和相位并综合考虑冷、热态下的振动均衡的基础上,在发电机转子端部加重,有效地控制了带负荷后的发电机振动。

Analysis and Control of Unstable Vibration of 600-MW Generator Rotors

The bearing-pad vibration and shaft vibration of a 600-MW hydrogen-cooled generator rotor of a power plant have been keeping on intensifying with increasing unit loading since its operation. Through the tests of the active power variation, rotor current variation and hydrogen temperature variation, the main cause of the vibration is figured out that new mass imbalance is generated by heat distortion at the end component of the generator rotor due to the poor manufacturing process. Consequently, the third-order vibration occurs, which causes the vibration to become severer. The amplitude and phase of the heat distortion are calculated and in consideration of the vibration balance under the cold and hot states, the vibration of the generator rotor is harnessed effectively by adding weights at the end of the generator rotor.