The 240 MVA motor generators for the Reisseck II pumped-storage plant

The motor generators for the Reisseck II pumped-storage plant owned by Verbund Hydro Power (VHP) have been among the most challenging generators in terms of design and manufacture for Andritz Hydro over the past decade. The new cavern powerplant connects the existing Reisseck/Kreuzeck and Malta complexes. With a rated output of 240 MVA, 50 Hz, and a rated speed of 750 rpm, the generators are among the most powerful units globally in terms of output per pole and with air as the cooling medium. To fulfil a number of stringent technical requirements, a special pole fixation design had to be reactivated and incorporated in the modern design. Special design features and 3D computational fluid dynamic and conjugate heat transfer techniques for extreme low ventilation losses had to be applied. By calculating the entire efficiency rate (without bearing losses as specified by the customer) a guaranteed value of 99.24 per cent resulted for the entire optimization of the design.