Did You Know...
...that the inventor of the electric motor was a blacksmith named Thomas Davenport? Described as "a brilliantly unsuccessful inventor", Davenport invented the first rotary electric motor. In 1836 he headed out -- on foot -- from his Vermont home to file a patent application at the Patent Office in Washington, D.C. By the time he got there, he had squandered away his money and couldn't afford the $30 filing fee so he turned around and went home. When he later mailed in his application with money he'd raised, the Patent office was destroyed in a fire. He did finally get credit for his invention on Feb. 5, 1837.
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| Number | Title | Issue Date |
| 8164296 | Method and apparatus for determining a field current in brushless electrical machines A method and an apparatus are described for determining a field current through a field winding in an electrical machine with a stator and a rotor. The electrical machine includes a field-circuit transformer to produce, by induction of an electrical current on the r... | 04/24/2012 |
| 8076894 | Superconductive rotating electric machine drive control system and superconductive rotating electric machine drive control method The present invention provides a superconductive rotating electric machine drive control system that has higher efficiency and is smaller size and lighter in weight than conventional systems, and also provides a superconductive rotating electric machine drive contro... | 12/13/2011 |
| 8018187 | Initial polarity detection for permanent magnet motor drives Methods and apparatus are provided for aligning a control reference axis with a magnetic north of a permanent magnet motor. The method includes the steps of injecting a predetermined stator current on an estimated reference axis of the permanent magnet motor and int... | 09/13/2011 |
| 7977910 | Method of starting a synchronous motor with a brushless DC exciter A starting method and system for a motor where the motor may be started as an induction motor by applying a magnetizing current to build flux through the stator, with the field current set at the maximum permissible exciter stator current (i.e., the current that wil... | 07/12/2011 |
| 7863852 | Motor and control circuit thereof A control circuit of a motor includes at least two sensor chips and at least two winding sets. The sensor chips are electrically connected to each other, and each of the winding sets has a first winding and a second winding. The first end of the first windings and t... | 01/04/2011 |
| 7663334 | Synchronous machines The present invention relates to electrically magnetized synchronous machine comprising an electrically magnetized rotor, and electrically supplied sator windings, whereby it further comprises non-linear means, optionally controllable, such as rectifying means in a ... | 02/16/2010 |
| 7508158 | Excitation system for synchronous machine A synchronous machine regulator is provided to simplify an adjustment work of current distribution to thyristors, the synchronous machine regulator having a circuit board 32 mounting a gate drive circuit 33 for supplying a gate pulse to each of thyrist... | 03/24/2009 |
| 7508157 | Line synchronous air core motor A motor system includes an air core motor having a rotor with opposed permanent magnet poles defining therebetween a magnetic airgap and driving magnetic flux across the magnetic airgap. A stationary armature with air core windings is located within the magnetic air... | 03/24/2009 |
| 7443128 | Method and device for controlling motors An electronic device is provided for controlling a motor having three phases driven by a motor driver. In one implementation, the electronic device includes a detection means and a control circuit. The detection means includes three high-gain differential amplifiers... | 10/28/2008 |
| 7439696 | Rotating electric machine and manufacturing method thereof A control device of a rotating electric machine to which an inverter is integrally assembled is downsized, and manufacturing costs are reduced. An inverter for controlling outputs from the rotating electric machine is integrated with a rotating electric machine, and... | 10/21/2008 |
| 7378814 | Method for controlling a wound rotor synchronous motor A method for the control of a wound rotor synchronous motor comprises measuring a plurality of electromagnetic entities indicative of the operation of the motor, generating voltage on a stator of the motor to obtain a stator current, further generating a further vol... | 05/27/2008 |
| 7372223 | Electric drive control apparatus and method An electric drive apparatus has an electric motor having a rotor and a stator; and a magnetic pole position detecting portion having a sensor rotor attached to the rotor, and a sensor stator that is adjacent to the stator, and that is fixed to a case, and that exten... | 05/13/2008 |
| 7358698 | Field-winding type of synchronous machine A field-winding type of synchronous machine comprises a stator with an armature winding wound phase by phase, a rotor having a rotor core with a field winding wound, and a circuit enabling an armature current to pass the armature winding, the armature current corres... | 04/15/2008 |
| 7339333 | Motor drive control apparatus, motor drive control method and program of the same A general-purpose comparator can be used as a comparison processing module to reduce the costs of a motor drive control apparatus. The apparatus has an electric machine; a magnetic pole position computation processing module; a pattern generation processing module; ... | 03/04/2008 |
| 7339344 | Self tuning method and apparatus for permanent magnet sensorless control A plurality of parameters of a Permanent Magnet Synchronous Motor (PMSM) is determined by a motor controller for differentiating between a plurality of PMSMs. This is achieved by first applying regulated DC motor currents at a commanded fixed rotor angle and measuri... | 03/04/2008 |
| 7330010 | Method for operating a rotating electrical machine and apparatus for carrying out the method A method is specified for operating a rotating electrical machine (1), which machine (1) has at least two sets of stator windings (A, B), in each case one associated converter unit (2) being provided for each set of stator windings (A, B) and ea... | 02/12/2008 |
| 7279859 | EC motor and method for operating same In a method for operating an EC motor, position-measurement signals are recorded by a position-measuring device, and, on the basis of the position-measurement signals, commutation instants are determined, at which the current supply to the EC motor is commutated. At... | 10/09/2007 |
| 7276876 | Synchronous motor driving apparatus A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic po... | 10/02/2007 |
| 7269039 | Method and device for producing rectifier gating signals using feed forward control A device includes an active rectifier (14) having control gates controllable to produce an output voltage on a DC bus (20), a gate control circuit (16) for producing gate control signals for controlling the active rectifier control gates, a firs... | 09/11/2007 |
| 7256511 | Turbine-generator equipment and installation method thereof Installation method of turbine-generator equipment controlling a turbine-generator is described. The method includes manufacturing a thyristor excitation equipment as a package including a circuit breaker, an excitation transformer, a power rectifier coupled with th... | 08/14/2007 |
| 7245104 | Position-sensorless motor control device A position-sensorless motor control device has a superposer that superposes, on the drive current with which the motor is driven, a superposed current having a different frequency than the drive current, a superposed component extractor that extracts, from the motor... | 07/17/2007 |
| 7239103 | Synchronous motor startup lock detection circuit and method A startup failure detection system provides an indication of motor startup failure based on a flux amplitude signal value. The flux amplitude signal is derived from motor flux estimations in combination with a rotor angle estimation. The flux amplitude signal value ... | 07/03/2007 |
| 7235947 | Synchronous motor control method and synchronous motor control system A desired q-axis current is determined based on a desired torque, and a desired d-axis current is determined based on the rotating speed of a synchronous motor when the terminal voltage of the synchronous motor coincides with a predetermined maximum permissible volt... | 06/26/2007 |
| 7193388 | Offset PWM signals for multiphase motor A multi phase motor includes a switching array for interconnecting a power source to each phase. A current sensor senses current supplied from the power source via the switching array to the winding and a controller generates offset PWM signals for controlling the s... | 03/20/2007 |
| 7190145 | Method and apparatus for improving speed measurement quality in multi-pole machines A method and apparatus for improving speed measurement quality in systems having multi-pole machines is taught. The method compensates for pole misalignment by computing speed based upon moving average techniques. In one embodiment, a moving average speed averaged o... | 03/13/2007 |
| 7187152 | AC servo drive without current sensor An AC servo drive without current sensor includes a PI (proportional integration) controller, at least two first-order controllers (polar point and zero point), a decoupling compensator, a coordinate converter, a pulse width modulator, a counter and a speed estimato... | 03/06/2007 |
| 7180263 | Synchronous motor control method and device Synchronous motor controlling apparatus and method controls power applied to minimize or eliminate speed variations of a synchronous motor due to variations in load imposed the motor. The rotational position of a rotor of the synchronous motor based on the input ter... | 02/20/2007 |
| 7164243 | System and method for establishing motor efficiency during balanced or unbalanced operating conditions A system and method for establishing a plurality of operating parameters of a multiphase motor. The plurality of electrical parameters may be established from stator resistance data and electrical input data. The system and method may be used to decompose the electr... | 01/16/2007 |
| 7161325 | Lead-angle control method and device for operating permanent magnet synchronous motor in flux weakening regions A lead-angle control device according to the present invention includes: a space voltage vector controller calculating effective vector application times necessary for obtaining output voltage vectors of an inverter from stationary-coordinate-system instruction volt... | 01/09/2007 |
| 7157878 | Transient compensation voltage estimation for feedforward sinusoidal brushless motor control A method for controlling a voltage mode controlled electric machine comprising: receiving a torque value representative of a desired torque; obtaining a speed value indicative of a rotational velocity of the electric machine; acquiring a phase advance value indicati... | 01/02/2007 |
| 7141952 | Determination of start commutation in synchronous servo-drives Method for the determination of start commutation in synchronous servo-drives by means of two coupled control loops, a current control circuit and an angle control circuit. The angle control circuit contains an incremental position sensor signal. A ramped desired va... | 11/28/2006 |
| 7129672 | Controller apparatus for synchronous motor and controlling method thereof For providing a controller apparatus for a synchronous motor and a controlling method thereof, enabling to be manufactured, easily and cheaply, and to obtain a lock mechanism, but without necessity of mechanisms, such as, an electromotive lock mechanism, wherein the... | 10/31/2006 |
| 7126306 | Motor control unit Windings of each phase in a three-phase AC motor are independent of one another. A motor control unit gives, to windings of each phase (U, V and W-phase), currents (IU, IV, IW) obtained by adding, to a fundamental sine wave current, a current having a frequency whic... | 10/24/2006 |
| 7102305 | Apparatus and method for controlling motor A motor control apparatus includes a direct-current power source and an inverter circuit, which includes a switching element. The motor control apparatus receives a current command value in every control cycle and calculates a current deviation accumulated value by ... | 09/05/2006 |
| 7081735 | System and method for bypassing a motor drive A motor control system comprising a plurality of motor controllers and a power source adapted to drive an electric motor. The motor control system comprises a switch that is selectively operable between at least a first position and a second position. In the first p... | 07/25/2006 |
| 7045986 | Position sensing method and apparatus for synchronous motor generator system A position sensing apparatus (300) derives rotor position of a synchronous machine (200) from signals output from the machine (200). In one embodiment, the position sensing apparatus (300) comprises: a bandpass filter (322) that fi... | 05/16/2006 |
| 6992451 | Motor control apparatus operable in fail-safe mode In a motor feedback control, the current supply phase is set on the basis of the encoder count of an encoder and the current supply phase is also set on the basis of the encoder count by time-synchronous processing. In the feedback control, a maximum value or a mini... | 01/31/2006 |
| 6984958 | Method for defining quadrature-axis magnetizing inductance of synchronous machine Method for defining quadrature-axis magnetizing inductance of a synchronous machine, the synchronous machine being supplied by an inverter. The method comprises steps, wherein the synchronous machine is started without load or with reduced load; the rotor current of... | 01/10/2006 |
| 6960898 | Control unit for controlling a synchronous motor A control unit is provided that controls a motor that opens and closes a door of an electric train such that, if an abnormality is detected by a position sensor, continuation of its open/closing operation can be maintained. The control unit includes an arrangement f... | 11/01/2005 |
| 6954050 | Control method and control device of permanent-magnet type synchronous motor The object of the invention is to inhibit the axial displacement caused by the insufficiency of a control response angular frequency of a frequency arithmetic unit of a synchronous motor and realize high-precision torque control also in acceleration/deceleration. To... | 10/11/2005 |
