Hydraulic-mechanical coupling vibration performance of pumped storage power station with two turbine units sharing one tunnel

摘要

The paper studies the hydraulic-mechanical coupling vibration (HMCV) performance of pumped storage power station (PSPS) with two turbine units sharing one tunnel (TTUSOT) based on overall transfer matrix. Firstly, the model of PSPS with TTUSOT is established by overall transfer matrix method. The overall transfer matrix is derived. Then, the effects of hydraulic parameters and mechanical parameters on vibration performance are analyzed. Finally, the HMCV performance under three operating conditions is studied. The results show that the HMCV is superposed by the nine orders of vibrations. The hydraulic parameters and mechanical parameters can affect specific orders of vibrations and change the stability. In overlapping interval, one value of surge tank area corresponds to two values of the 1st order of vibration. The operating condition affects the stable domain by changing the 2nd order of attenuation factor. When the 2nd order of attenuation factor increases from negative to positive with the increase of integral gain of governor, the stability of PSPS changes from stable to unstable. When the load changes are undertaken by two turbine units simultaneously, the situation of equal distribution of load changes has a better stability than that of unequal distribution of load changes.