Abstract: In electrical machines having a stator core formed by groups of stacked laminations spaced axially one from the other to define with spacers therebetween a plurality of radially extending cooling ducts, there is provided transition inserts in the flow passages. The inserts have surfaces which in part define the flow paths and form gradual transition surfaces between the flow path sections to minimize flow losses. The flow path surfaces of the transition inserts may be linear or curvilinear.

Abstract: A cooling gas ventilation circuit is provided for an end winding of a rotary machine having a rotor of the type having a plurality of radial slots and a plurality of coils respectively seated in the radial slots, the coils extending beyond a pole face of the rotor to form the end winding. The ventilation circuit is composed of first and second cooling gas passages, respectively defined in at least one turn of each coil of the end winding. Each first cooling gas passage extends from an inlet port in communication with a cavity on one longitudinal side of the turn to an exit port defined on the other longitudinal side of the turn. Each second cooling gas passage extends from an inlet port in communication with the cavity on the one longitudinal side of the turn to an outlet in the form of a radial chimney defined through a plurality of the turns of the coil within the respective radial slot.

Abstract: A synchronous generator is disclosed having main power windings and auxiliary power windings, where the auxiliary power winding is coupled to a variable frequency drive system. The variable frequency drive causes the generator to function as a motor and turn a drive shaft to start a gas turbine. Switching circuits are used to connect and disconnect the auxiliary windings of the generator with the variable frequency power supply.

Abstract: A synchronous generator is disclosed having main power windings and auxiliary power windings, where the auxiliary power winding is coupled to a variable frequency drive system. The variable frequency drive causes the generator to function as a motor and turn a drive shaft to start a gas turbine. Switching circuits are used to connect and disconnect the auxiliary windings of the generator with the variable frequency power supply.