| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 318767000 |
Primary circuit control
| 320 |
| 318729000 |
Power-factor control
| 15 |
| 318757000 |
Braking
| 11 |
| 318739000 |
Reversing
| 6 |
| 318766000 |
Primary and secondary circuits | 5 |
| 20080303476 | ELECTRIC MOTOR CONTROL DEVICE - An excitation current processor of a current controller processes the excitation current corresponding to the magnetic flux instruction from the magnetic flux instruction processor. It multiplies this excitation current with a boost coefficient to obtain an excitation current instruction. Here, the boost coefficient is determined based on the difference obtained by subtracting the magnetic flux estimation value processed by the magnetic flux processor based on the excitation current feedback from the voltage conversion device from the magnetic flux instruction input from the magnetic flux instruction processor. Further, the boost coefficient can be found from the function of time from the start of the rise of the magnetic flux. | 12-11-2008 |
| 20100052599 | INVERTER DEVICE - An inverter device driving an induction motor including main and auxiliary windings both having different winding specifications includes a three-arm inverter circuit having phase output terminals connected to the main winding, the auxiliary winding and a neutral winding of the induction motor respectively and converting a DC power supply to two-phase substantially sinusoidal PWM voltage, a current detector detecting currents of the respective main and auxiliary windings from a DC power supply current, a vector control computing unit obtaining balanced inductance values and resistance values from inductance values and resistance values of the respective main and auxiliary windings, determining a two-phase voltage to be supplied to the induction motor by vector control computing based on the balanced inductance values and resistance values, and a PWM signal forming unit forming a PWM signal controlling the inverter circuit according to the two-phase voltage. | 03-04-2010 |
| 20120056577 | Control System for Single-Phase Induction Motor and Control Method for Single-Phase Induction Motor - The present invention refers to a control system for a single-phase induction motor comprising at least one electronic control circuit ( | 03-08-2012 |
| 20120091941 | Flux controller for induction motor - Disclosed is a flux controller for maintaining reliable flux estimation performance in a low velocity region, the controller including a velocity controller, a torque current controller for outputting a torque voltage command, a flux controller for outputting a flux current command, a flux current controller for receiving the flux current command to output a flux voltage command, a three-phase converter for converting the torque voltage command and the flux voltage command into a three-phase voltage command applied to the induction motor to output the three-phase voltage command, a flux estimator for outputting a rotating angle of a rotor of the induction motor, an estimated flux value of the rotor and an estimated velocity of the rotor, and a flux regulator for receiving the torque voltage command and the estimated velocity to output a gain value that regulates a magnitude of the flux command. | 04-19-2012 |
| 20140062380 | APPARATUS FOR ESTIMATING PARAMETER IN INDUCTION MOTOR - An apparatus for estimating a parameter of an induction motor is provided. The estimating apparatus receives an output from a current controller and d and q-axis currents in a synchronous reference frame applied to an induction motor, calculates an error of rotor resistance, and obtains a difference between the rotor resistance and nominal rotor resistance. | 03-06-2014 |
| 318818000 |
Secondary circuit control | 2 |
| 20090085511 | High Temperature Superconducting Electromechanical System With Frequency Controlled Commutation For Rotor Excitation - A system and method for generating a magnetic field in a rotating machine. In one embodiment, a primary winding assembly is configured to generate a rotatable magnetic field. The assembly is connected to receive multiple signals of different phases to effect field rotation. A set of secondary windings is positioned for generation of current based on magnetic coupling during the field rotation. The secondary windings include conductor capable of supporting superconducting current flow. A rotatable machine includes a stator and a rotor winding coupled for rotation with respect to the stator. The secondary windings are formed in a circuit for providing superconducting current through the rotor winding. | 04-02-2009 |
| 20110050157 | INDUCTION MOTOR - An active reactive induction motor is provided. The motor comprises two sets of three-phase windings. One set of windings carries the active power and is called the power windings. The second set of windings carries the reactive power and is called the flux windings. The power windings carrying the active power provides more power to the induction motor than the flux windings carrying the reactive power. A driver circuit for driving the active reactive induction motor and the corresponding modes of operation is also provided. | 03-03-2011 |
| 318738000 |
With commutated winding | 1 |
| 20090102413 | ELECTROMECHANICAL FLIGHT CONTROL SYSTEM AND METHOD FOR ROTORCRAFT - Flight control systems and methods for rotorcraft are provided. The flight control system includes a user input device and a motor in operable communication with the user input device. The motor includes a plurality of winding sets and an armature coupled to the plurality of winding sets. The armature includes multiple magnets. The winding sets and the armature are configured such that when one or more of the plurality of winding sets are selectively energized, the armature moves relative to the one or more of the plurality of winding sets. | 04-23-2009 |
| 318730000 |
With plural separately movable rotors | 1 |
| 20100097027 | METHODS AND APPARATUS FOR CONTROLLING MULTIPLE A.C. INDUCTION MACHINES FROM A SINGLE INVERTER - Methods and apparatus are provided that include or provide a first three-phase induction machine including stator windings, a second three-phase induction machine including stator windings, wherein the stator windings of the first machine are coupled in series with the stator windings of the second machine, and an inverter circuit that provides a three-phase output signal coupled to the stator windings of the first machine. Other aspects are also provided. | 04-22-2010 |
| Entries |
| Document | Title | Date |
|---|
| 20090284211 | METHOD AND APPARATUS FOR ESTIMATING INDUCTION MOTOR ELECTRICAL PARAMETERS - A method and apparatus to provide estimates of electrical parameters for line-connected induction motors during either steady-state or dynamic motor operations. The electrical parameters are calculated from the motor nameplate data and voltage and current measurements. No speed sensors or electronic injection circuits are needed. The method can be divided into 4 major steps. First, complex space vectors are synthesized from voltage and current measurements. Second, the instantaneous rotor speed is detected by calculating the rotational speed of a single rotor slot harmonic component with respect to the rotational speed of the fundamental frequency component. Third, the positive sequence fundamental frequency components are extracted from complex space vectors. Finally, least-squares estimates of the electrical parameters are determined from a dynamic induction motor equivalent circuit model. | 11-19-2009 |
| 20100231159 | Power Conversion Device - A power conversion device includes a converter that converts AC power to DC power, a converter controller that controls an output voltage of the converter, an inverter that converts the DC power to AC power at a variable frequency, an inverter controller that controls an output frequency of the inverter, and a current detector that detects an AC current on an input side of the converter. It is configured in such a manner that the inverter controller adjusts a slip frequency of the induction motor in response to a fluctuation of the AC current on the input side of the converter detected by the current detector. It thus becomes possible to suppress a beat current in an output current of the inverter at the occurrence of a load fluctuation as well as a power supply voltage fluctuation. | 09-16-2010 |
| 20140139174 | METHOD FOR ESTIMATING A FREQUENCY OF A HARMONIC IN AN AC CURRENT PASSING TO/FROM AN AC MACHINE - A method for estimating a frequency of a harmonic in an AC current passing to/from an AC machine. The method includes observing an AC current passing to/from an AC machine that includes a stator and a rotor; measuring phase fluctuations in the observed AC current; and using the measured phase fluctuations to estimate a frequency of a harmonic in the AC current. The method includes using the estimated frequency of the harmonic in the observed AC current to estimate a speed of the rotor of the AC machine. The method may be implemented by a controller, which may include a PC and/or a DSP. | 05-22-2014 |
| 20160197640 | MOTOR DRIVE SYSTEM AND METHOD | 07-07-2016 |
