Abstract: A connector design for connecting rotor coil end turns and an exciter/rectifier assembly to a rotor bore copper conductor in a dynamoelectric machine. The design includes a terminal stud or pin sized to be closely received in a telescoping manner in a cylindrical receptacle which is fixedly attached to the rotor windings. A similar cylindrical receptacle extends from the other end of the rotor toward the exciter/rectifier assembly. The stud or pin in each case is also modified to include grooves for accepting resilient, sliding electrical contacts so that a resilient electrical contact is obtained when the stud is positioned within the receptacle. The connector elements are also sufficiently rigid as to withstand shock, centrifugal forces at operational speeds, and rotation direction reversal, but which also allows sufficient radial and axial movement to accommodate coil movement associated with rotor temperature and speed changes while simultaneously maintaining a low resistance current path.

Abstract: A fluid draining system for an electric power generator of the type containing a cooling gas under pressure includes oil-pressurized shaft seals adjacent the rotor bearings, to prevent the pressurized gas from escaping through the bearings. Oil is at a pressure higher than the pressurized gas and means are provided to automatically drain leakage oil from the bottom of the generator. The automatic drain includes a differential pressure valve with its first inlet connected to the drain in the bottom of the generator, its second inlet connected to the gas pressure within the generator, and its outlet completing the drain path for the system when the differential pressure of the first inlet exceeds that of the second inlet by a preset amount.

Abstract: A control device, such as a U-shaped member including opposingly directed tab projections connected to the upstanding arms of the member may be coupled to a space block of a dynamoelectric machine for limiting motion, especially inward radial motion, of the block. In one embodiment, the space block has a groove for forming a portion of a keyway between the space block and a flange and the tabs of the member are disposed in the keyway radially outward a key which is dimensionally smaller than the groove, so that the tabs abut a sidewall of the groove, thereby limiting motion of the block when the key contacts the tabs.

Abstract: A three-phase generator includes an internal neutral junction to which one end of each of the windings of the generator is connected thereby forming a wye-connected generator. An air-core current transformer is disposed over each of the three conductors leading to the internal neutral junction for monitoring neutral current therein. A corresponding air-core current transformer is disposed over high-voltage terminals connected to the other ends of the generator windings. A shielded differential amplifier on the output of each air-core current transformer produces a signal corresponding to the difference between two bifilar half windings in its associated air-core current transformer. The difference currents from the neutral and high-voltage ends of each generator winding are compared, and, if their difference exceeds a predetermined threshold, a threshold circuit produces a trigger signal which is latched by a latching relay to produce a trip signal for use by the generator control system.

Abstract: A common neutral bus is formed in a lower frame extension of a large three-phase generator by disposing three sets of neutral current transformers within the lower frame extension and interconnecting the three phases downstream of the neutral current transformers to form an internal neutral bus. The neutral bus is connected to an external neutral transformer through a neutral terminal of small size and low cost. Clamshell clamps are provided in the internal neutral bus for isolating the neutral ends of the generator winding for test purposes. Rigid support of the current transformers and a hollow copper tube passing therethrough permits use of light and low-cost hollow copper tubing in place of the relatively substantial and expensive neutral terminals conventionally required.

Abstract: A terminal plate is permanently affixed to a stator frame below the connector rings. High-voltage bushings are installed in the terminal plate at the user's site. Conducting bars are employed between each connector ring and its respective high-voltage bushing. Each conducting bar terminates at a short tangential distance from a connecting portion of its related high-voltage bushing. Domed flexible straps interconnect the conducting bars with the high-voltage bushings, the domed portions of the straps oriented to absorb relative motion engendered by tangential forces on the stator core and connector rings.