| Patent application number | Description | Published |
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| 20080315822 | Rotor position detection at standstill and low speeds using a low power permanent magnet machine - For a multiphase alternating current (AC) wound field synchronous machine (WFSM) that has a stator with a selected number of poles, the WFSM having an associated exciter and multiphase AC permanent magnet machine (PMM) directly coupled to the WFSM, a method of sensing the position of a rotor in the WFSM comprises the steps of: configuring a stator for the PMM to have a number of poles that is a sub-multiple of the selected number of WFSM stator poles; configuring a rotor for the PMM to have high saliency; applying multiphase AC power of a selected frequency to the PMM stator: detecting at least one set of stator harmonic currents of the multiphase AC power resulting from the rotor saliency; converting the detected PMM harmonic stator currents from their multiphase coordinates to αβ coordinates; rotating the converted PMM stator currents into a reference frame for at least one selected harmonic to generate αβ coordinate harmonic current vectors; and estimating the position of the WFSM rotor based on the values of the αβ coordinate harmonic current vectors in the selected harmonic reference frame. | 12-25-2008 |
| 20090009129 | Active damping for synchronous generator torsional oscillations - A generator control unit (GCU) provides active damping of a synchronous generator by monitoring the speed of the synchronous generator and detecting oscillations in the monitored speed. The oscillations are indicative of torsional oscillations within the mechanical drivetrain including the synchronous generator or generators. In response to detected oscillations in the monitored speed, the GCU generates a varying set-point value that is used to control the excitation voltage provided to the synchronous generator. Varying the excitation voltage provided to the synchronous generator causes a variation in synchronous generator torque. By selectively varying the torque in the synchronous generator, the GCU provides active damping in the synchronous generator that decreases or dampens the torsional oscillations. | 01-08-2009 |
| 20100175478 | Torque Oscillation Monitoring - A method of detecting and monitoring torsional oscillation in a mechanical coupling between a prime mover and a multiphase alternating current (AC) electrical generator, comprises the steps of: detecting in at least one received signal variations that are indicative of changes in the rotational speed of the electrical generator; extracting information from the detected variations that are indicative of torsional oscillation to produce a torsional oscillation signal that has information relating to at least the amplitude of the torsional oscillation; and monitoring the torsional oscillation signal to determine the presence and severity of the torsional oscillation in the mechanical coupling. | 07-15-2010 |
| 20100327820 | ACTIVE DAMPING FOR SYNCHRONOUS GENERATOR TORSIONAL OSCILLATIONS - A generator control unit (GCU) provides active damping of a synchronous generator by monitoring the speed of the synchronous generator and detecting oscillations in the monitored speed. The oscillations are indicative of torsional oscillations within the mechanical drivetrain including the synchronous generator or generators. In response to detected oscillations in the monitored speed, the GCU generates a varying set-point value that is used to control the excitation voltage provided to the synchronous generator. Varying the excitation voltage provided to the synchronous generator causes a variation in synchronous generator torque. By selectively varying the torque in the synchronous generator, the GCU provides active damping in the synchronous generator that decreases or dampens the torsional oscillations. | 12-30-2010 |
| 20110115444 | ELECTRIC LOAD DAMPER FOR DAMPING TORSIONAL OSCILLATION - An electric load damper assembly includes a synchronous generator operable to provide a plurality of phases of electrical output in response to a mechanical input from a rotating shaft. An electric load damper includes a phase leg for each of the plurality of phases. Each phase leg includes a resistive load, a snubber and at least one solid state switch. The at least one solid state switch is in parallel with the snubber, and the at least one solid state switch and snubber are collectively in series with the resistive load. A controller is operable to receive a signal indicative of a rotational speed oscillation of the synchronous generator, and is operable to selectively reduce a torsional oscillation of the shaft by diverting electrical current from the synchronous generator through the resistive load of each of the plurality of phases in response to the signal exceeding a predefined threshold. | 05-19-2011 |
| 20110266987 | SYNCHRONOUS DISTURBANCE SUPPRESSION IN A VARIABLE SPEED MOTOR DRIVE - A variable speed drive for an electric motor has an inverter for receiving pulse width modulation controls. The inverter communicates power signals to a poly-phase electrical motor. A resolver communicates signals from the poly-phase motor back to a motor control. The motor control includes a speed control, a field-oriented control, and a pulse width modulation drive for driving the inverter. The resolver is connected to the speed control and to the field-oriented control, and further communicates with a synchronous compensator. The synchronous compensator is configured to drive the harmonic content at a target frequency or frequencies in a selected signal towards zero over time. | 11-03-2011 |
| Patent application number | Description | Published |
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| 20090171177 | System And Method For Attaching A Sensor To A Patient's Skin - A method and apparatus for affixing a sensor adjacent a tissue site is disclosed. In an embodiment, the spectrophotometric sensor comprises, a sensor body, one or more light emitters, one or more photodetectors, and a light scattering medium capable of increasing at least one of the effective detection area of the one or more photodetectors or the effective emission area of the one or more light emitters. | 07-02-2009 |
| 20100280582 | DEVICE, SYSTEM AND METHOD OF REMOVING HEAT FROM SUBCUTANEOUS LIPID-RICH CELLS - Devices, systems and methods for removing heat from subcutaneously disposed lipid-rich cells are disclosed. In selected embodiments, suction and/or heat removal sources are coupled to an applicator. The applicator includes a flexible portion and a rigid portion. The rigid portion includes a thermally conductive plate and a frame coupling the thermally conductive plate and the flexible portion. An interior cavity of the applicator is in fluid communication with the suction source, and the frame maintains contiguous engagement between the heat removal source and the thermally conductive plate. | 11-04-2010 |
| 20110066016 | OPAQUE, ELECTRICALLY NONCONDUCTIVE REGION ON A MEDICAL SENSOR - A medical sensor may be adapted to prevent unwanted light and electrical interference from corrupting physiological measurements. Sensors are provided with features that reduce the amount of outside light or shunted light that impinge the detecting elements of the sensor. The sensor is adapted to reduce crosstalk between electrical signals, increasing the accuracy of measurements. The sensor is also adapted to reduce the effect of outside light or shunted light on pulse oximetry measurements. | 03-17-2011 |
