Class / Patent application number | Description | Number of patent applications / Date published |
322029000 | Speed or frequency of generator | 28 |
20080258693 | Method for Controlling an Electromagnetic Retarder and System Including Retarder and a Control Unit - A method for controlling an electromagnetic retarder from a control unit said retarder including an electrical generator. The inventive method is used to determine an excitation current intensity to be injected into the primary coils of the generator of the retarder, said retarder including a rotary shaft bearing the secondary windings of the generator a n d field coils which are supplied b y the secondary windings. The rotation speed of the rotary shaft is taken into account in order to select a lower intensity if the rotation speed of the shaft is higher. The invention is suitable for use in the field of electromagnetic retarders which are intended for heavy vehicles such as trucks. | 10-23-2008 |
20080265846 | METHOD FOR THE ACTIVE DAMPING OF THE DRIVE TRAIN IN A WIND ENERGY PLANT - A method for the active damping of a drive train in wind energy plant, with the following steps: the actual value of the generator rotational speed is acquired and amplified via an oscillatory delay element, the oscillatory delay element has a predetermined natural oscillation frequency (ω | 10-30-2008 |
20080303490 | GENERATOR WITH QUADRATURE AC EXCITATION - A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required. | 12-11-2008 |
20090051332 | System and method for electric current and power monitoring and control of a generator - A control device measures a voltage drop across a conductor in a generator to determine and control the total generator output current. A temperature of the conductor is also measured to improve the accuracy. The control device may further improve on the accuracy by compensating for the electrical current through a field coil that may power the generator. The control device may be used in combination with a generator in a vehicle electrical system. Other system parameters may be monitored to improve on the system monitoring, diagnostics, and control. The generator may include a conductor comprising a process-controlled geometric shape. | 02-26-2009 |
20090066297 | Power Generation Apparatus Using AC Energization Synchronous Generator And Method Of Controlling The Same - A power generation apparatus and method includes an AC energization synchronous generator, a switching device which connects to a network disposed on a stator side of the AC energization synchronous generator, an energizing device which applies a variable frequency AC to a secondary winding of the AC energization synchronous generator, and a first voltage detection unit which detects a voltage of the switching device on the stator side. A rotational frequency of the AC energization synchronous generator is estimated or calculated based on a frequency of a stator side voltage of the switching device, while the switching device is open. | 03-12-2009 |
20090121688 | POLE COUNT CHANGING GENERATOR - Disclosed is a pole count changing generator capable of altering the number of poles contained within a generator. This pole count change is accomplished by changing the path through which electrical current is capable of traveling in response to a control signal sent to a pole count changing circuit. | 05-14-2009 |
20090134847 | Target regulation voltage setting apparatus - The target regulation voltage setting apparatus for a vehicle on which a vehicle alternator is mounted includes a first function of calculating a large first-order delay and a small first-order delay of a rotational speed of the vehicle alternator at regular time intervals, a second function of making a judgment on a running state of the vehicle by determining whether or not the vehicle is in one of an accelerating state and a decelerating state on the basis of a variation of the large first-order delay supplied from the first function, and determining whether or not the vehicle is in a normal state on the basis of a variation of the small first-order delay supplied from the first function, and a third function of determining a target regulation voltage of the vehicle alternator in accordance with a judgment result of the second function. | 05-28-2009 |
20090212747 | Power control system and method - This invention discloses a power control system comprising a prime mover and a generator driven by the prime mover. A control device is coupled with the generator to ascertain a change in speed of the generator and vary an output power of the generator according to the change. The control device applies a signal to reduce the generator output power and another signal to restore the generator output power. The power control system may include a transmission, a speed converter, and/or an accessory. | 08-27-2009 |
20090278510 | System for generating electrical power - Described is a system for generating electrical power, which system includes a turbine that is mechanically connected to a generator, which in turn is connected via a multiphase transformer to a load. In at least one embodiment, at least two counter-connected switching devices of the converter are assigned to each phase of the transformer. The transformer is provided on the side facing the converter with two winding arrangements in a star connection. Each of the windings of the first winding arrangement is connected to the switching devices belonging to one phase and switched in one direction. Each of the windings of the second winding arrangement is connected to the switching devices belonging to one phase and switched in the opposite direction. The star points of the two winding arrangements are connected via a direct current choke. | 11-12-2009 |
20090315522 | SELF-EXCITED CONTROLLED FREQUENCY GENERATOR SYSTEM WITH BI-DIRECTIONAL CONVERTER - A controlled frequency generating system (CFG) may be constructed with a main generator and an exciter driven by a common shaft. Excitation power may be provided from the common shaft; as distinct from prior-art systems which may require independent excitation power sources. While controlling the output voltage and frequency of the main generator, the bi-directional controller extracts power from a main generator output and may supply the extracted power to supplement excitation power when needed at certain rotational speeds. The controller may extract power from the exciter when, at other rotational speeds, the exciter produces excess power. The extracted excess power may be delivered to the output of the main generator to maintain a desired level of output power at a desired frequency, irrespective of speed of rotation of the CFG. | 12-24-2009 |
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 |
20110267012 | Methods and Apparatuses for Elimination of Torque Pulsation in Doubly Fed Induction Generators Using the Field Reconstruction Method - Methods and apparatuses for substantially eliminating torque pulsation in a doubly fed induction machine are disclosed. An example method comprises: measuring a stator current of the doubly fed induction machine, measuring a rotor current of the doubly fed induction machine, calculating a total magnetic flux density in an airgap of the doubly fed induction machine, calculating a tangential force density, calculating an electromagnetic torque, repeating the calculation of the electromagnetic torque over one electrical cycle to estimate a torque pulsation, determining a new rotor current that substantially eliminates the torque pulsation by referencing a set of optimal rotor currents in a look-up table, and changing the rotor current in response to the determination. Other embodiments are described and claimed. | 11-03-2011 |
20120091973 | VEHICLE-USE ELECTRIC ROTATING MACHINE - A vehicle generator includes armature windings, rectifier module groups, an upper MOS on-timing determining section, a lower MOS on-timing determining section, a rotational speed calculating section, a target electrical angle setting section for setting a value of a target electrical angle, an upper MOS off-timing determining section, a lower MOS off-timing determining section, and drivers for driving high-side and low-side MOS transistors constituting upper and lower arms. The target electrical angle represents a margin period between when the low-side MOS transistor was turned off a half cycle ago and the moment when the lower arm on-period has ended. The upper MOS off-timing determining section and the lower MOS off-timing determining section set off timings of the MOS transistors such that the margin period is equivalent to the set value of the target electrical angle. | 04-19-2012 |
20120126758 | HIGH VOLTAGE DC POWER GENERATION - A DC power system includes a permanent magnet generator (PMG), and an active rectifier in electrical communication with the PMG. The active rectifier is adapted to actively rectify power output from the PMG if the PMG is operating at low speed, and the active rectifier is further adapted to passively rectify power output from the PMG if the PMG is operating at high speed. | 05-24-2012 |
20120306457 | METHOD AND APPARATUS FOR OPERATING A POWERTRAIN SYSTEM IN RESPONSE TO ACCESSORY LOAD - A powertrain system includes an electric machine mechanically coupled to an internal combustion engine mechanically coupled to a transmission. A method for operating the powertrain system includes determining an engine stall threshold rate during engine operation in a low load condition. A time-rate change in an accessory load is controlled by the electric machine operating in an electric power generating mode in response to the engine stall threshold rate during the engine operation in the low load condition. | 12-06-2012 |
20130278228 | METHOD OF CONTROLLING SPEED OF A VARIABLE SPEED GENERATOR - Some embodiments relate to a method of controlling speed of a variable speed generator. The method includes detecting a load of the variable speed generator and determining a target speed for the variable speed generator based on the load supplied by the variable speed generator. The method further includes using a controller to adjust the speed of the variable speed generator based on the target speed. The method may further include correcting the target speed by calculating a correction factor that corrects the target speed based on a voltage produced by the variable speed generator. | 10-24-2013 |
20150035501 | SYSTEMS AND METHODS FOR CONTROLLING TORSIONAL OSCILLATION IN WOUND FIELD SYNCHRONOUS GENERATOR MACHINES - A method for controlling torsional oscillation includes detecting angular position of a wound field synchronous generator machine, extracting information indicative of torsional oscillation, selecting synchronous torsional oscillations, compensating for the synchronous torsional oscillations with an exciter signal, and controlling field current in the wound field synchronous generator using the exciter signal. A damping controller includes a damping module with a synchronous selective compensator and a synchronous notch filter for generating torsional oscillation compensation signals for asynchronous torsional oscillation. | 02-05-2015 |
20150048806 | Method for operating a separately excited electric machine in a motor vehicle - A method for operating a separately excited electric machine, in particular, a generator of a motor vehicle, where an exciting current flows through a rotor winding of the electric machine at a nominal current intensity during a normal operation and at a holding current intensity in an idling operation; the holding current intensity being greater than zero and less than the nominal current intensity. | 02-19-2015 |
20150102783 | METHOD OF CONTROLLING SPEED OF A VARIABLE SPEED GENERATOR - Some embodiments relate to a method of controlling speed of a variable speed generator. The method includes detecting a load of the variable speed generator and determining a target speed for the variable speed generator based on the load supplied by the variable speed generator. The method further includes using a controller to adjust the speed of the variable speed generator based on the target speed. The method may further include correcting the target speed by calculating a correction factor that corrects the target speed based on a voltage produced by the variable speed generator. | 04-16-2015 |
20160204725 | SELF ADJUSTING GENERATOR SPEED CONTROL | 07-14-2016 |
322030000 | Centrifugal of fly weight governor | 2 |
20120068670 | WIND JET TURBINE - A wind jet turbine with a housing that creates an air density deferential between the air within the housing and the wind passing outside the housing in order to generate the same or more electrical power in less space than traditional wind turbines. | 03-22-2012 |
20130069604 | PERMANENT MAGNET GENERATOR - A permanent magnet generator having the unique feature of a speed proportionally adjusted air gap for self-regulation of coil output voltage over a wide range of operating rotational speed of a steam turbine to which the invention is coupled. The Permanent Magnet Generator rotor is supported by the turbine end shaft and the stator is supported by a bracket bolted to the turbine pedestal base or other rigid structure. The speed proportional air gap is accomplished through the use of a plurality of centrifugal flyweights in mechanical coupling to a spool piece under spring load and to corresponding rare earth magnets via linkage such that increasing rotor speed extends the flyweights outward from the rotor center of rotation and draws the rare earth magnets closer to the rotor center of rotation and thus increases the air gap. | 03-21-2013 |
322032000 | Frequency responsive devices or networks | 6 |
20100277134 | METHOD FOR OPERATING A WIND ENERGY INSTALLATION - The invention relates to a method for operating a wind energy plant having a double-fed asynchronous machine, at least one inverter and at least one control device, wherein electrical energy is at least partly supplied into a grid via the inverter, the inverter comprises per phase at least one power semi-conductor module with at least two transistor circuits and at least two free-wheeling diodes and the inverter by using the control device is actuated at least at times via a pulse width modulation (PWM). The object, namely of providing a generic method for operating a wind energy plant in which an improved power output is effected even in the low-noise rotational speed range of the rotors, is achieved in that, at frequencies of the current to be impressed by the inverter on the machine side of less than 10 Hz, preferably less than 6 Hz, the switching-on duration and/or the switching frequency of the transistor circuits and/or of the free-wheeling diodes of the inverter are altered via the control device by taking their thermal heating into account. | 11-04-2010 |
20110068753 | GENERATOR WITH QUADRATURE AC EXCITATION - A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required. | 03-24-2011 |
20120306458 | CONVERSION OF SYNCHRONOUS GENERATOR TO SYNCHRONOUS CONDENSER - An approach for converting a synchronous generator to a synchronous condenser is disclosed. In one aspect, a variable frequency driver is used to provide a starting power source to accelerate a synchronous generator decoupled from a turbine to an operational speed to act as a synchronous condenser. In another aspect, the synchronous condenser can be recoupled back to the turbine to form the synchronous generator. | 12-06-2012 |
20140015497 | Balancing Vibrations At Harmonic Frequencies By Injecting Harmonic Balancing Signals Into The Armature Of A Linear Motor/Alternator Coupled To A Stirling Machine - Vibrations at harmonic frequencies are reduced by injecting harmonic balancing signals into the armature of a linear motor/alternator coupled to a Stirling machine. The vibrations are sensed to provide a signal representing the mechanical vibrations. A harmonic balancing signal is generated for selected harmonics of the operating frequency by processing the sensed vibration signal with adaptive filter algorithms of adaptive filters for each harmonic. Reference inputs for each harmonic are applied to the adaptive filter algorithms at the frequency of the selected harmonic. The harmonic balancing signals for all of the harmonics are summed with a principal control signal. The harmonic balancing signals modify the principal electrical drive voltage and drive the motor/alternator with a drive voltage component in opposition to the vibration at each harmonic. | 01-16-2014 |
20140062425 | SYSTEM AND METHOD FOR INTERFACING VARIABLE SPEED GENERATORS TO A POWER GRID - The present subject matter is directed to systems and methods for interfacing variable speed generators to a power distribution grid. A plurality of doubly-fed induction generators (DFIG) are provided and coupled to a common shaft of a prime mover. Each of the plurality of DFIGs provides an electrical power output having an output frequency based on a rotational speed of the common shaft. A converter coupled to each DFIG provides variable excitation signals to its respective DFIG sufficient to adjust its output frequency to conform to a power grid frequency requirement. | 03-06-2014 |
20140347019 | VOLTAGE-CONTROLLED DC LINK FOR VARIABLE FREQUENCY GENERATOR EXCITATION - Apparatus for controlling the excitation current of a variable frequency generator (VFG) including means to create a voltage-regulated DC link using PMG power and frequency information, the latter being the image of the VFG mechanical input speed. A step-down voltage-controlled chopper is inserted between the passive rectifier stage and the excitation current control chopper. The control law of this voltage-controlled source is such that when the mechanical input speed of the VFG increases, its output (controlled DC-link voltage) decreases non-linearly, leading to DC link voltage varying from V (engine at idle) to V/2 (engine at take-off speed). The DC voltage becomes inverse-proportional to input mechanical speed. | 11-27-2014 |