发电机组扭振相互作用的研究

Analysis on Torsional Interactions of Turbo-generators

发电机组间扭振相互作用的存在性是多机组系统能否进行简化的前提条件,但一些相关的结论一直未给出理论依据,而机组间扭振相互作用的现场测试也难以实现。该文提出描述机组间扭振相互作用强度的扭振相互作用系数(T IF),作为评估机组间扭振相互作用是否存在的一个指标。采用时域仿真对相同机组、相似机组以及不同机组在各种情况下的扭振相互作用进行研究,并考察了系统强度、发电机输出功率以及机组阻尼等参数对机组间扭振相互作用的影响。结果表明,发电机组之间的扭振相互作用随机组自然扭振频率偏差的增大而锐减;对于不同发电厂中的发电机组,不管其机械轴系参数是否相同,相互之间不存在明显的扭振相互作用。而对于同一电厂中的发电机组,机组相互之间存在着很强的扭振相互作用。

The precondition to reduce power systems for SSO study is that there are no torsional interactions between turbine-generator （T-G） sets. But some conclusions about torsional interactions of units have never been validated so far since field tests on turbine-generator units are difficult fo perform. So in this paper torsional interactions of turbine-generator units were studied by time domain simulation. In order to describe the strength of the torsional interactions of the studied units,torsional interaction factor （TIF）was defined and was taken as an index to estimate the existence of torsional interactions of units. Identical turbinegenerator units, similar units and non-identical units under various situations were all considered. Furthermore, the effects of parameters such as the strength of the system, the output power of the generator ,and the damping of the units on the torsional interactions were investigated. The results show that the torsional interactions sharply decrease with the increasing differences in the mode frequency of the units. And whether the units are identical or not, there are stations. Contrarily ,the torsional interactions between no evident interactions between the units in different the identical units in the same station are significantly strong.