Abstract
Traditional type pumped storage system contributes to adjust the electric power unbalance between day and night, in general. The pump turbine unit is prepared for the power stabilization system, in this serial research, to provide the constant power with good quality for the grid system, even at the suddenly fluctuating/turbulent output from renewable energies. In the unit, the angular momentum change through the front impeller/runner must be the same as that through the rear impeller/runner, that is, the axial flow at the outlet for the axial flow at the inlet. Such flow conditions are advantageous to work at not only the pumping mode but also the turbine mode. This report discusses experimentally the performance of the unit, and verifies that this type unit is very effective to both operating modes.
