Abstract: A 7-level wye-connected H-bridge converter that provides redundancy for continued operation when one bridge phase has failed and more particularly to a topology that includes multiple semiconductor H-bridges and a three-phase semiconductor mid-bridge. The converter may continue operation with failure of any bridge, as a three-phase, wye-connected H-bridge by bypassing the failed bridge. Individual bridges of the converter may be operated at different dc-bus voltages to maximize power output. The converter may employ synchronous gating signals for the semiconductor devices of the bridges, including a zero-current notch waveform for minimizing harmonic distortion of the output waveform.

Abstract: A method is provided for attaching a shim to at least one of a base of a stator vane unit and a ring segment of a ring segment assembly in a gas turbine compressor. The method includes providing a shim shaped to conform to an engaging face of the base of the stator vane unit or the segment ring of the segment ring assembly, with a predetermined thickness dimension; boring at least one hole, normal to the face of the shim and extending fully through the thickness dimension of the shim; positioning the shim on the engaging face of the at least one of the base of the stator vane unit and the segment ring of the segment ring assembly; and welding the shim to the engaging face of the at least one of the base of the stator vane unit and the ring segment of the stator ring assembly.

Abstract: The first stage nozzles have airfoil profiles substantially in accordance with Cartesian coordinate values of X, Y and Z set forth Table I. The X and Y values are in inches and the Z value is in inches along the nozzle stacking axis coincident with a turbine radius. The X and Y distances may be scalable as a function of the same constant or number to provide a scaled up or scaled down airfoil section for the nozzle. The nominal airfoil given by the X, Y and Z distances lies within an envelope of±0.160 inches.

Abstract: A radiation detector assembly is provided. The radiation detector assembly includes a radiation detector element and a light detection element operationally connected to the radiation detector element. The radiation detector element is seated within a housing. The assembly also includes a plurality of continuous wave formed springs located along the outer periphery of the radiation detector element, radially between the housing and the radiation detector element.

Abstract: An exciter system for the field of a synchronous generator excitation is provided. The exciter system includes an AC power source; a three-phase thyristor bridge having six legs, the three-phase bridge being connectable with the AC power source, and being adapted to provide a variable DC voltage output; a thyristor in each of the six legs of the three-phase bridge, wherein the thyristors provide a path for a device current; and a three-phase AC line filter series, including series resistive and capacitive elements across each phase of the AC power source and a plurality of bleed resistors, wherein at least one bleed resistor is connected to each AC input connection of the filter.

Abstract: A method for water jet stripping and recontouring of a coated article of manufacture is provided. The method includes dimensionally scanning the coated article and establishing a three-dimensional model for the coated article. The method further includes establishing a set of reduced dimensional profiles for recontouring and then analyzing whether the reduced profiles are satisfactory for subsequent operation. A jet spraying program is established for removal of the coating and the surface base material to each predetermined reduced dimensional profile.