Investigation of transients in reversible pumped-storage station hydraulic machines

Conclusions

Experimental investigations into the nature of transients occurring in a reversible hydraulic machine with loss of drive in pump operation and load shedding in turbine operation have demonstrated that, for reversible radial-axial hydraulic machines, pump operation is the determining factor as regards pressure increase in the volute chamber, and speed variation and load variations on the guide-vane equipment. The choice of minimum closure time of the guide-vane equipment is of great importance, from the standpoint of preventing the unit from approaching the counter-flow range. In order to prevent a substantial pressure increase in the volute chamber and pipeline in the second stage of the transient process either automatic delay in closure of the guide-vane equipment or free no-load water discharge from the volute chamber as the pressure rises above the permissible limit may be provided.