Vibration fault processing experiment and analysis of hydropower unit
Ruilian Wang , Yunda Gao
COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(12D) 233-239
School of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou, Henan, 450045, China
To find the truth of unit vibration fault more accurately and timely, mathematical model is led in archetypal test analysis. The measuring point of vibration is selected reasonably. The caution of vibration fault is judged preliminarily according to the change of the vibration in each measuring point as changing speed, exciting voltage, load and phase modulation operation test. The parameters in sample are chosen on the basis of the vibration fault characteristic and then the mathematical model is established based on fuzzy analysis. The membership grade of vibration characteristic parameters is gotten by the ascended half Cauchy distribution function, the fuzzy relational matrix is gotten from the experience of experts evaluation by fuzzifying the relationship between vibration fault characteristic parameter and fault type, then the membership grade matrix of vibration fault type is composed by the membership grade of vibration character parameter and fuzzy relational matrix. Vibration fault causation is confirmed through the data in the membership grade matrix of the vibration fault type and the disposal measure is chosen. For the example of a certain unit whose upper guide bearing vibrating exceeding standard, the cause judged preliminarily is imbalance of mass in the unit. The swing indexes in the rated speed and rated exciting voltage are regard as sample, and then the imbalance of mass and excessive gap in upper guide bearing are judged as the major causation of the hydroelectric generating set based on the membership of the vibration fault type. Because the vibration fault of unit doesn’t eliminate when the upper guide bearing overhauling, the station decided to conduct experiment of dynamic balance. After the disposal, the fault problem is radically solved.