Study On Dynamic Characters Of Hydropower House With Long Distance Tunnel

Realizing the rapid development of the hydropower technology, high flow headand capacity already became a vital part of hydropower development. Thehydropower plant security issues have taken to a new level. As the powerhousebecome larger and more complex, its vibration is extreamly complex. It is affected bymany factors. Research on the combined effect mechanism of hydraulic, mechanicaland electromagnetic vibration of the hydropower plant and unit is a necessarytechnical methods to reveal the vibration principle. The research has a great positiveeffect on optimizating running status of power station, improving the operationefficiency and ensuring the safety of the plant.Taking its reference from a long diversion power station of high head, large flowand big stand-alone capacity, field test and theoretical analysis method is carried outto achieve the objective of the research which is considered the hydropower plant andunit as a whole. The details of main research are as follows:(1)Based on the variable load and variable exciting current on the target powerstation test data, we obtain the time-domain analysis, amplitude-domain analysis,frequency-spectrum analysis, vibration source analysis and correlation analysis. Andthe powerhouse is divided into six areas. By use the wavelet analysis theory we obtainthe dynamic response of various kinds of main frequency bands.(2) The dynamic response analysis on the coupled system of units and plants ofthe transient process is made by analyzing the measured data. The research is basedon the result of the field test of load shedding, over speeding and startup andshutdown of the unit. The analysis and calculation on theoretical solution of waterlevel in the transient surge has carried on. Analysing the field test data of surge tankwater level in load shedding process, we obtain the transient flow characteristics oflong diversion power station.(3) Three-dimensional finite element simulation of prototype structure of plantis set up, the action of unit on plant is transmitted by additional quality elements.Modal calculation, formation analysis and resonance verification of the plant modelunder different boundary conditions are achieved. Dynamic coefficient verification ofvibration source frequency on horizontal, vertical and tangential direction is madebased on modal analysis. The force in three directions acting on the plant is calculated, harmonic response analysis is checked on the plant foundation. Pulsation harmonicresponse analysis of hydraulic vibration source frequency in flow pass is achieved.