Research On Vibration Monitoring Of Powerhouse Of Quxue Hydropower Station

As one of the main sources of vibration,hydropower station is mainly subjected to electromagnetic and hydraulic loads.Based on the measured vibration signals of the underground powerhouse of Quxue hydropower station,the chaotic characteristics,vibration source transmission path and vibration operation state monitoring are studied in this paper.This paper is mainly from the following three aspects :(1)Research on chaotic characteristics of hydropower plant.Based on the quantitative method of saturation correlation dimension and maximum Lyapunov index,the chaos characteristics are analyzed.The vibration signal is decomposed into a series of IMF by introducing CEEMDAN-SVD.The vibration source composition of IMF component is determined by spectrum analysis;the saturation correlation dimension and maximum Lyapunov index representing different vibration source components are calculated.The chaos characteristic analysis are verified by using different chaotic characteristics index,so as to make the vibration system of hydropower station produce chaos.The results show that the chaos of the power plant is under certain conditions,and the tail water fluctuation is the main factor of chaos in the vibration system of the hydropower plant.(2)Research on vibration transmission path of hydropower plant.The long period of vibration fluctuation,large influence range and long transmission path caused by the wake vortex belt are the important factors that cause the low frequency vibration of the head cover and draft tube wall.The main transmission path is: the draft pipe to the pier(stator foundation and lower frame foundation)and then to the upper floor of the hydropower station.The transmission information rate calculation method is introduced to verify the transmission law of vibration caused by wake vortex band in the power plant by the transfer entropy.(3)Monitoring of the vibration operation state of hydropower plant.As a bearing body with multiple loads,the hydropower station has complex vibration sources and scattered vibration position.It is difficult to realize the monitoring of the whole structure operation state by traditional methods.Multi-channel weighted multi-scale permutation entropy algorithm is proposed to monitor the overall operation state of the vibration.The results show that MWMPE can monitor the whole operation state,and it is suitable for monitoring the safe operation.The proposed MWMPE provides a new idea and application basis for the safety diagnosis and operation management.