Abstract: An automatic voltage regulator senses and controls the terminal voltage of a separately excited generator by controlling the field current applied to the field winding. In order to improve the response time of the circuit, the circuitry relies on the phasor relationships between the generator phase voltages to obviate the need for a rectification and filtering circuit, used in known AVR's. More specifically, each of the sinusoidal phase voltages is sampled and squared. The squared phase voltages are then summed together. The square root of the sum is used to provide a DC voltage signal, proportional to the terminal phase voltages V.sub.A, V.sub.B and V.sub.C. The DC voltage signal may then be compared with a reference signal to generate an error signal for use in regulating the generator terminal voltage by controlling the field current applied to the generator field winding.

Abstract: A PC computer monitors the energy, power, voltage, and current consumed at a plurality of local stations placed behind the electrical meter of the utility company for individual billing of the local users, a bidirectional communication line being used therebetween. A command from the PC computer causes at each station the power, voltage, current and totalized energy to be stored, and thereafter the PC computer derives individually the results for separate estimations and central billing.

Abstract: The coil holding current of a contactor is regulated to the lesser of two measurements of coil current during each cycle of the full-wave rectified control voltage to compensate for induced flux in the coil generated by load current through the main contacts of the contactor, thereby preventing uncontrolled drop out of the contactor.

Abstract: The present invention is an airborne radar system which scans the flight path of an aircraft with two radar scans, an upper elevation pointing above local level and a lower elevation scan pointing below the glide slope. The radar returns from the upper elevation scan are used to detect the core of the microburst. The core and a model of the windshear which uses the core are used to select angles and range cell candidates, in a lower elevation scan, for hazard detection processing. The candidates in the lower scan, which is pointing at the ground, are used to create a hazard map tested against a predetermined hazard threshold. A threshold violation results in a pilot alert. The hazard map includes a vertical factor determined through model coefficients in the radial outflow as a function of altitude.

Abstract: A tool for use in installing O-ring seals in the removable head of a nuclear reactor pressure vessel. Disclosed are two embodiments of the tool. One embodiment is adapted to fit within the stud bolt holes of the flange of the removable head of the pressure vessel. The other embodiment is adapted to be magnetically attached to the underside of the flange of the removable head of the pressure vessel. The tool uses a movable support arm to properly position and support the O-rings in their respective grooves machined in the underside of the flange of the removable head.

Abstract: An integrated information system is provided for a plant with interactive processes running in functional equipment subsets, such as a nuclear power generation plant. Sensors are operatively coupled to monitor processes and equipment in the plant, collecting sample data for assessing operational conditions and for predicting maintenance requirements based on loading of the equipment. One or more processors access the sample data and compares present conditions to diagnostic specifications, technical specifications and historical data stored in memory and indexed to equipment subsets and functional operating groups. The processor(s) generate prioritized reports to alert users to potential operational and/or maintenance problems. In addition to the prioritized reports, the processor accesses and outputs to the users reports of the diagnostic and technical specifications applicable to the process parameters exhibiting the potential problems.

Abstract: A gas turbine power plant has coolant injected into the combustors in order to reduce the level of nitrogen oxide produced by the combustion of natural gas fuel and/or oil. A control system controls injection of coolant into the combustors in order to reduce NOx emissions, while improving turbine cycle efficiency and avoiding the possibility of over-injection of coolant to the point of flame-out in the combustor. PID controllers are used to provide percentage error bias in the control system, whereby adjustment of coolant injection follows turbine load in a manner that increases turbine efficiency.

Abstract: A zirconium sponge regulus from a Kroll reduction process is contaminated with zirconium chlorides, unreacted magnesium and magnesium chloride. The sponge regulus is vacuum distilled at a temperature of at least 800.degree. C. and then cooled. Before opening the distillation vessel and exposing the sponge regulus to the atmosphere, the vessel is backfilled with a gas comprising 25% to 75%, by volume, carbon dioxide, carbon monoxide or mixtures thereof, with the balance an inert gas and impurities associated therewith.The sponge regulus is less susceptible to fires when exposed to the air or crushing in downstream processing, and the metal surfaces of the sponge regulus are passivated whereby the overall contamination of the sponge is significantly reduced.

Abstract: A method for shot peening a first tube external to and concentric with a second tube comprising the steps of forming a slot through the second tube; positioning a shot peening device adjacent the notch in the second tube for propelling shot peening balls; propelling the shot peening balls through the slot in the second tube for shot peening the second tube; and rotating the second tube in increments for shot peening an entire circumferential portion of the first tube positioned outwardly and radially from the slot.

Abstract: A fault current surge bypassing and transitional impedance compensation system for preventing subsynchronous currents on electrical power lines, with parallel lines being protected from the clearing of transient faults. Capacitor banks serve as only a partial solution to the disturbances with transient faults during conventional recovery modes of operation. The fault current bypassing and impedance compensation system, coupled in series to each transmission line, clears a transmission line fault current and dynamically balances the inductor impedance on the transmission line after the fault mode clears when a return is made to the normal mode of operation. A circuit based solid-state switching power converter or "voltage-sourced inverter" with self-commutating GTO semiconductor switches is used, having all GTOs switched-on and maintained in this condition for the fault current to pass.

Abstract: A segmented stretch waveform for wide band high duty cycle tracking application. The waveform is divided into multiples of two spaced segments as the tracking range closes. Target returns received during spaced segments are combined to correspond to the complete waveform; and range is determined in accordance with the combined waveform. Tracking range can be varied without changing bandwidth, FM slope, duty cycle or processing time.

Abstract: An electrical control system includes multiple frames of reference in the error path of a controller. In each such frame, a particular chosen component of the error vector appears as a constant vector and is passed through a pure integrator thus acquiring infinite gain. In the steady state, the net error vector can then be forced to have zero content at each of the targeted frequencies (as set by the rotational velocity of the frames of reference). Both parallel and series configuration of the controller are provided, as well as the control methods used by the controllers.

Abstract: A once-through boiler for producing steam from water comprising a boiler vessel having an interior portion, an inlet for passing the water into the boiler vessel, and an outlet. A first conduit is attached to the inlet for passing the water through said boiler vessel and is disposed in the interior of the vessel. A heater positioned within said interior portion and operable to generate heat for evaporating the water in the first conduit. A second conduit is connected to said first conduit at one end of the second conduit and to the outlet at the other end of the second conduit; wherein the second conduit passes the steam generated in the first conduit, and the heater is operable to heat the steam passing through the second conduit; wherein the second conduit attaches to the first conduit in the interior of the boiler vessel, passes externally to the vessel, and thereafter passes into the interior of the boiler vessel where the second conduit connects to the outlet.

Abstract: A non-contact surface flaw detection system for workpieces such as nuclear fuel pellets transports the pellets continuously along an illuminated path while rotating them. A line scan camera records a series of line scans for the pellets and the resulting values of pellet reflectivity are digitized. Pixel values are compared to thresholds defined adaptively by averaging and/or using a video finite impulse response filter, to generate a binary map of "good" and "bad" pixels, that also defines the edges of the pellet in the map. A processor counts and associates bad pixels to logically define and assess blobs of bad pixels. The processor checks for coincidence of the edge pixels with a nominal edge line that best fits the edge, for finding edge flaws. The pellets assessed in this manner are selected or rejected. Camera sensor elements are normalized for gain and offset. Shifting of the pixel data cancels skew produced in scanning moving pellets.

Abstract: The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header.

Abstract: A dual polarized cross notch array employing a positioner for locating and grounding metallized portions of unrestrained element ends with respect to metallized restrained element ends. The positioner is a planar member having spaced rows and slots in intersecting rows and columns. Conductive tabs are formed adjacent to the slots at the intersections of the rows and columns corresponding to intersections of the element ends. The conductive tabs receive corresponding portions of the intersecting element ends in secure mechanical engagement and electrical contact. The positioner maintains the polarized elements rigidly in orthogonal configuration. In alternative embodiment employs conductive members preferably formed of tape at the inside corners of the array. Improved radiator elements and a positioner for preconfiguring the array is also disclosed.

Abstract: An array of transducer elements receives energy from a target or targets in a field of view and operates on the transducer outputs to provide a plurality of different levels of shading. The most useful portion of the field pattern is selected and combined with other most useful portions of other field patterns into a single composite display which results in one or more relatively narrow lobes, indicating targets, and without the presentation of side lobes which may be masking targets.

Abstract: A segmented electromagnetic coil assembly for use in a magnetic jack type of drive mechanism used to move control rods within a nuclear reactor. The coil assembly has a plurality of individual magnetic coils spaced around and against the non-magnetic housing which contains the control rod drive shaft.

Abstract: A device, system and method of image processing and compression are preferably used with second generation infrared (IR) detector arrays where the pixel size is less than the optical blur of the system. Raw input pixels are compressed such that output pixels are more closely matched to the optical blur of the system. Further, the number of output pixels are compressed from a greater number of input pixels, based upon a selected input-to-output compression ratio. The ratio is not constrained to be of an integer value. The compression takes place using a plurality of neighborhood processors, each corresponding to a different output pixel type. Each neighborhood processor contains a plurality of different predetermined weighed fractions of input pixel data and are used to produce compressed output pixel data, based upon the selected input-to-output compression ratio and the output pixel type, for real-time processing.