Generator-Motors for Pacific Gas and Electric´s Helms Pumped Storage Project

The design and construction of Pacific Gas and Electric´s Helms Project represent the state of the art in pumped storage technology. This paper describes concepts associated with the design of the generator-motors for this installation. Included are details concerning the machine´s direct water cooled stator winding, advanced rotor ventilation system, thrust bearing configuration, structural design, and dynamic performance.