300Mvar调相机瓦振跳机问题分析及处理  

Analysis and Treatment of the Trip Accident Caused by Bearing Vibration of the 300Mvar Synchronous Condenser

作　　者：马天逵 张芬芬 MA Tiankui;ZHANG Fenfen(State Grid Jiangsu Electric Power Co.,Ltd.,Extra-high Voltage Branch Company,Nanjing 211102,China)

机构地区：[1]国网江苏省电力有限公司超高压分公司,南京211102

出　　处：《大电机技术》2024年第3期51-56,共6页Large Electric Machine and Hydraulic Turbine

摘　　要：随着特高压直流输电系统的发展,电网送、受端安装了大容量调相机用于提供动态无功支持,以防止换相失败。某换流站调相机启动调试期间,励端X向瓦振超标跳机。结合振动伯德图和瀑布图发现,原因为调相机升速阶段穿越转子三阶副临界转速时,产生2倍频共振,共振频率与轴承系统某固有频率接近,导致轴承系统发生共振。现场通过分步试验的方式,逐步调整轴承系统刚度、更换轴承座等,以避开转子2倍频共振频率,并增强阻尼。试验后发现瓦振问题有一定改善,但仍超过正常运行要求。随后现场调整了励端轴承座顶部应急油箱的固定方式,并对应急油箱结构进行优化,发现励端瓦振明显降低,机组启停机阶段瓦振达到安全运行要求。With the development of UHVDC transmission system,large capacity synchronous condensers are installed in power grid to supply dynamic reactive power compensation and prevent commutation failure.During the start-up and commissioning of the synchronous condenser in a converter station,the bearing vibration of the synchronous condenser on excitation end at X-direction exceeded the standard level,which led to a trip accident.Combined with the Bode diagram and the waterfall diagram of the vibration,it was found that the reason was that the double-frequency resonance occurred when the synchronous condenser passed through the third-order sub-critical rotating speed of the rotor during the acceleration process,and the resonant frequency was close to a certain natural frequency of the bearing system,resulting in mechanical resonance.Then the stiffness of the bearing system was adjusted step by step and the bearing seat was replaced to avoid the double-frequency resonance frequency of the rotor and to enhance the damping on site.It was found that the problem of bearing vibration has been improved to some extent,but it still exceeded the normal operation requirements after the test.Subsequently,the fixing method of the emergency oil tank at the top of the bearing seat on excitation end was adjusted,and the structure of the emergency oil tank was optimized.It was found that the bearing vibration on excitation end was significantly reduced,and the bearing vibration during start-up and shut-down process of the synchronous condensers reached the requirements of safe operation.

关 键 词：特高压直流输电系统 调相机 轴承系统 转子 振动 

分 类 号：TM342[电气工程—电机]