Abstract: A method is provided for performing a transfer from gas fuel operation to liquid fuel operation in a gas turbine with a dual fuel system. The method includes initiating a predetermined uncontrolled liquid fuel prefill flow rate through the liquid fuel system, sensing an onset of the uncontrolled liquid fuel flow to the combustor nozzles, and initiating transfer from gas fuel operation to liquid fuel operation when the flow of uncontrolled liquid fuel at the combustor nozzles is sensed. The onset of uncontrolled liquid fuel flow to the combustor nozzles is determined by monitoring changes of Fuel Normalized Power (FNP), a parameter sensitive to uncontrolled liquid fuel flow, and determining when FNP exceeds a threshold algorithm value.

Abstract: An integrated fault and personnel protection system and method for a multi-thread converter in a wind turbine power system is provided. The structure and method provide for system optimization, as well as, arc flash protection. Fault sensing with means of removing power applied to the converter minimizes the energy available to produce an arc flash event. Sensing and disconnects devices for the protections are provided close to the source of energy to protect more of the system. Converter controls detect, identify and isolate faults selecting the best combinations of the novel specific fault isolation devices. Components are distributed into separate physical to enhance protection.

Abstract: A system and method are provided to isolate outputs of parallel converter threads of a power system converter of a wind turbine generator by utilizing isolated power windings on the output transformer from the converter. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

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.

Abstract: A method for calculating the amount of solution components to add to an advanced coating removal (ACR) stripping solution in a coating removal stripping bath to replenish and recover stripping potential. The stripping effectiveness may be restored by the addition of only the primary acid of the composition of acids of the stripping bath and fresh water, in an amount necessary to restore the stripping solution to its original density.

Abstract: A system and method are provided to isolate outputs of parallel converter threads of a power system converter on a generator side of a wind turbine generator by utilizing isolated power windings on the wind turbine generator. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

Abstract: A fully bladed closure design for a turbine wheel with tangential entry. A set of the final three buckets including a bladed closure bucket are disposed about a wheel margin with two buckets adjacent to the bladed closure bucket secured to the wheel margin by the dovetails. The closure bucket is secured to adjacent buckets by a combination of one or more retaining keys and to the margin by one or more retaining pins. The bladed closure bucket and the adjoining faces of the adjacent buckets have flat skirts providing suppport from the retaining keys across the full axial width of the bladed closure bucket and the adjacent buckets.

Abstract: A wind turbine blade that includes integrated erosion, lightning and icing protection for a leading edge. The leading edge includes a frontal surface with an erosion shield positioned external to the frontal surface. An internal lightning conveyance path is provided with an electrical connection from the erosion shield to the internal lightning conveyance path. A heat-generating element is positioned between the erosion shield and the frontal surface and a heat conduction path is provided from the heat-generating element to the erosion shield. Further, a structure is provided for connecting the heat-generating element to an energy source within the blade.

Abstract: A flexible and automatic system and method for blending an inexpensive secondary gas with a primary gas fuel for operation of a Dry Low NOx gas turbine. The secondary gas may be a gas fuel such as hydrogen, ethane, butane, propane and liquefied natural gas or an inert gas. Combustion dynamics are avoided by controlling the blended fuel within a permissible range for a Modified Wobbe Index. Combustion dynamics and gas turbine exhaust emissions may also be monitored to maintain safe combustion with the blended fuel. A gas turbine control system may adjust the blend and temperature of the primary gas fuel and the secondary gas to promote desired combustion.

Abstract: A disc brake arrangement is provided as adapted for a wind turbine generator incorporating a rotor shaft supporting a rotor wheel and support ring for a rotor structure surrounded by a stator structure within a generator casing. The disc brake arrangement includes a brake disc mounted normal to and concentric with the rotor shaft and operatively connected to the support ring. A plurality of disc brake calipers are arranged concentrically with the rotor shaft and adapted to engage the brake disc.

Abstract: An outer sidewall retention scheme for a singlet first stage nozzle of a gas turbine. The retention scheme includes a circumferential retaining ring with a main body and a pair of circumferential retaining lands projecting inward radially. A circumferential annular retaining groove is formed between the pair of circumferential retaining lands. A first lug and a second lug mounted on an outer face of the outer sidewall of each nozzle are adapted to fit within the circumferential annular retaining groove of the retaining ring and are supported radially and circumferentially by a first retaining pin and a second retaining pin, each pin passing though the circumferential retaining lands. Each nozzle further includes a chordal hinge rail and seal on the outer sidewall and a chordal hinge rail and seal on the inner sidewall providing axial support for the nozzle.

Abstract: A zero-current, synchronous switching waveform is provided for a three-phase, wye-connected H-Bridge to power an electric motor. The switching waveform includes two notches per cycle on the switching waveform provided to each of the semiconductor switches to minimize total harmonic distortion and switching loss. Positioning of the notch with respect to the zero-current crossing is optimized to reduce switching loss and minimize total harmonic distortion.

Abstract: A fluid dynamic polymer-based contact sensor measures ambient pressure based on the resistivity changes across the sensor under different ambient pressures. The pressure sensor may applied to airfoil structures such as wind turbine blades without impacting the blade structure and fluid dynamic characteristics. The sensor may also be applied to fluid measurements. The pressure measurements are used to measure blade performance with high fidelity. The pressure measurements are transmitted to processing to determine blade characteristics and environment including flow separation, stagnation point, angle of attack, lift and drag and wind speed. Further processing of the pressure distribution may identify wind shear, up-flow and yaw error.

Abstract: An article of manufacture having a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth TABLE I. The X and Y values are distances in inches, which when connected by smooth continuing arcs define airfoil profile sections at each distance Z in inches The X, Y and Z 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 +0.130 inch to ?0.030 inch.

Abstract: A wind turbine generator control system is provided for controlling output of a plurality of tightly-coupled windfarms connected at a point of common coupling with a power system grid. A master reactive control device employs algorithms whose technical effect is to coordinate the real power, reactive power and voltage output of the multiple windfarms. The controller incorporates a reactive power regulator that can be used to regulate reactive power, power factor or voltage at the point of common coupling and an active power regulator that can be used to regulate real power at the point of common coupling; such that each windfarm is not asked to contribute or violate its own operating capability.

Abstract: Methods and apparatus for continuing wind turbine operation when normal wind turbine motor control is unavailable due to overheating of one or more wind turbine control motors. Technical effects of the present invention include providing an effective control strategy continuing operation during over-heating of a wind turbine control motor, such as a pitch control motor and a yaw control motor.

Abstract: A method for controlling the rate of transfer between operation with gas and liquid fuel types to minimize the time in undesirable operational mode, thereby preventing excessive wear and damage to gas turbine hardware. The method includes completing a fuel prefill for the oncoming fuel type through the fuel system and determining if a total fuel demand for the oncoming fuel type is greater than a predetermined flow rate for the oncoming fuel type. The method also includes selecting a fuel transfer rate and transferring from the offgoing fuel type to the oncoming fuel type at the selected fuel transfer rate. Further, the method includes determining if the offgoing fuel flowrate has decreased below a predetermined flow rate for the offgoing fuel type, selecting a final fuel transfer rate and completing the transfer from offgoing fuel type to oncoming fuel type at a selected final fuel transfer rate.

Abstract: A stator bar installation fixture and method for installing stator bars into specific stator core slots within a stator core of rotating electrical equipment. The stator bar installation fixture includes rotating mechanisms, rotatingly fixed at each end of the rotating electrical equipment, for supporting and controlling an angular positioning of a stator bar insertion mechanism relative to the stator core. The stator bar insertion mechanism supports a stator bar within the stator core, angularly locates a stator bar in alignment with the specific stator core slot, and inserts the stator bar into the specific stator core slot.

Abstract: An integrated power plant cooling system for an electrical generating power plant driven by a gas turbine to cool power plant components is provided. The integrated cooling system includes a heat source extracted from the power plant and an absorption chiller utilizing energy from the heat source to cool a chilling medium. An integrated cooling skid includes heat removal devices for a plurality of power plant components. The chilling medium output from the absorption chiller is circulated to the heat removal devices for the power plant components of the integrated cooling skid. Plant cooling water may remove heat from the absorption chiller.

Abstract: A topology for a three-phase, wye-connected H-bridge converter allowing continued operation when one H-bridge phase has failed by bypassing the failed H-bridge, increasing dc-bus voltage to provide the required output load voltage, and decreasing switching frequency to reduce power losses in semiconductor switches. In normal operation, the dc-bus voltage is operated at a lower voltage, improving the reliability of power semiconductor devices. When an H-bridge is bypassed, the dc-bus is operated at a higher voltage but lower effective switching frequency, reducing semiconductor losses, allowing the converter to put out more current with the same temperature rise in the power switches.