The method for identifying the potential of the fast response capability of a variable-speed pumped storage turbine in pump mode

Abstract

Variable-speed pumped storage technology was being increasingly adopted by new power system to improve the operating and regulating characteristics of the hydropower unit and to stabilize the grid fluctuations. By connecting to a frequency converter, the variable-speed pumped storage unit can respond to grid fluctuations at a speed of hundreds of milliseconds. The fast response capability of a variable-speed pumped storage turbine should be considered in the design stage, be identified during the model test and be used as prerequisite during the commissioning stage of the unit. This article described the method for identifying the fast response capability and methods for improving the power regulation potential of a variable-speed pumped turbine in pump mode. The pipeline hydraulic loss, the guide vanes opening, the energy, cavitation and hump characteristics of the pump are the key parameters and should be carefully considered during the selection of the variable-speed operating zone.