Power Stabilization System with Unique Pumped Storage to Stabilize Momentarily Fluctuating Power from Renewable Resources (Counter-Rotating Type Pump-Turbine Unit Operated at Turbine Mode)

Abstract

This serial research proposes the hybrid power stabilization system with the counter-rotating type pump-turbine unit, to stabilize momentarily fluctuating power from renewable energy resources. In this paper, the experiments are verified that this type pump-turbine unit is reasonably effective to stabilize momentarily/instantaneously the unstably fluctuating power from renewable energy resources. Furthermore, an optimization for improving the hydrodynamic performance at turbine mode of this pump-turbine unit is carried out by using numerical analysis based on three-dimensional Reynolds-averaged Navier-Stokes equations. As a result, the optimization yielded a maximum increase in efficiency of 2.68% at the best efficiency point compared to a reference design. Detailed internal flow fields between the reference and optimum designs are analyzed and discussed in this work.