| Entries |
| Document | Title | Date |
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| 20080231224 | TIMER CIRCUIT AND TIME COUNT METHOD - A timer circuit includes a storage unit to store a series of first data content relating to a time into a specified address area, a target value generation unit to read the first data content from a read address of the storage unit and to generate, as a target value, third data content in which second data content is added to the first data content, a counter to perform counting and to output a count-up signal when the counting is performed up to the target value, and a control unit to sequentially designate a next read address of the storage unit at each count-up and to cause the series of operations of the target value generation unit and the counter to be executed. | 09-25-2008 |
| 20090021207 | ELECTRIC MOTOR CONTROL APPARATUS - A control apparatus for a multiphase AC electric motor having an inverter includes a current control including an abnormal-state current controller; an abnormal-state detector that detects an abnormal state of any of a wire of an electric motor, a wire of an inverter, and a wire connecting the electric motor to the inverter as an abnormal phase; and an abnormal phase disconnect. The abnormal phase disconnect disconnects one or more of phases detected to be in an abnormal-state and the abnormal-state current controller generates an abnormal state voltage command in accordance with detection of an abnormal state, and uses phases other than the disconnected phases of the inverter to control individual currents of the phases, with the abnormal-state voltage command used as a multiphase voltage command. | 01-22-2009 |
| 20100148718 | SEMICONDUCTOR ELEMENT AND ELECTRICAL APPARATUS - A semiconductor element ( | 06-17-2010 |
| 20100156338 | SYSTEM AND METHOD FOR MONITORING AND CONTROLLING STATOR WINDING TEMPERATURE IN A DE-ENERGIZED AC MOTOR - A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings. | 06-24-2010 |
| 20100194329 | SYSTEM AND METHOD FOR DETERMINING STATOR WINDING RESISTANCE IN AN AC MOTOR USING MOTOR DRIVES - A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current. | 08-05-2010 |
| 20110084643 | METHOD AND APPARATUS FOR FAILSAFE MONITORING AN ELECTROMOTIVE DRIVE - The invention relates to a method and to an apparatus for the failsafe monitoring of an electromotive drive ( | 04-14-2011 |
| 20110140646 | METHODS AND SYSTEMS FOR INDUCTION MACHINE CONTROL - A method for controlling an induction machine having a rotor includes the steps of obtaining a torque command, calculating an estimated squared value of resistance of the rotor using the torque command, determining an offset for the resistance of the rotor, and generating an updated measure of rotor resistance using the estimated squared value and the offset. | 06-16-2011 |
| 20110187308 | CONTROL DEVICE AND CONTROL METHOD FOR ALTERNATING-CURRENT MOTOR - When instructed to switch control modes between overmodulation PWM control and sinusoidal wave PWM control, control device corrects the amplitude of a voltage command signal based on a state of power conversion operation performed by an inverter, so as to suppress a change in an influence of dead time over a voltage applied to an alternating-current motor upon switching the control modes. The state of the power conversion operation performed by the inverter includes at least one of a present value of a carrier frequency in a control mode currently employed, an estimated value of the carrier frequency to be obtained when switching the control modes, the length of the dead time, a power factor of alternating-current power exchanged between the inverter and the alternating-current motor, and a driving state of the alternating-current motor. | 08-04-2011 |
| 20110285342 | METHODS AND SYSTEMS FOR INDUCTION MOTOR CONTROL - A method is provided for controlling an induction motor having a rotor. The method includes receiving a torque command; comparing the torque command to a threshold torque value; generating, with a first estimation module, a first estimated rotor resistance when the torque command is less than or equal to the threshold torque value; generating, with a second estimation module, a second estimated rotor resistance when the torque command is greater than the threshold torque value; and generating control signals for the induction motor based on the first estimated rotor resistance or the second estimated rotor resistance. | 11-24-2011 |
| 20120001586 | Power Conversion Device - A power conversion device includes a converter-inverter controller for controlling a converter and an inverter. The power conversion device further includes a DC capacitor connected between the converter and the inverter and a DC capacitor voltage detector for detecting a DC capacitor voltage Efc between the connection ends of the DC capacitor. The converter-inverter controller provides variable control on the DC capacitor voltage Efc to the converter on the basis of the motor frequency of an AC motor, the DC capacitor voltage Efc, and a pulse mode. Within a predetermined range of motor frequencies, the converter-inverter controller fixes the PWM modulation factor of the inverter to a value m | 01-05-2012 |
| 20120081065 | OVERCURRENT LIMITING FOR THE CLOSED-LOOP CONTROL OF CONVERTER-FED THREE-PHASE MACHINES - A method and a structure operate a three-phase machine, which is fed by a three-phase converter, using a stator flux regulator and either a slip frequency regulator or a torque regulator. A torque-forming fundamental-frequency current component of the stator current is limited by limiting a setpoint value that is supplied to the slip frequency regulator or to the torque regulator to a maximum slip frequency value maximum torque value. The flux-forming fundamental-frequency current component of the stator current is limited by limiting the speed at which a setpoint value supplied to the stator flux regulator changes to a maximum value. The maximum slip frequency value or maximum torque value is calculated on the basis of a prescribed maximum current value for a stator current fundamental-frequency magnitude of the stator current and on the basis of a filtered actual value of the flux-forming fundamental-frequency current component of the stator current. | 04-05-2012 |
| 20120098477 | METHODS AND DEVICES FOR ESTIMATION OF INDUCTION MOTOR INDUCTANCE PARAMETERS - Methods and devices are presented herein for estimating induction motor inductance parameters based on instantaneous reactive power. The induction motor inductance parameters, e.g., the stator inductance and the total leakage factor, can be estimated from motor nameplate data and instantaneous reactive power without involving speed sensors or electronic injection circuits. In one embodiment, the method includes: measuring voltages and currents; converting the measured voltages and currents into discrete-time voltage and current samples by analog-to-digital converters; synthesizing a complex voltage from the discrete-time voltage samples; synthesizing a complex current from the discrete-time current samples; acquiring and storing motor nameplate data; detecting instantaneous rotor speed by calculating an instantaneous rotor slot harmonic frequency with respect to an instantaneous fundamental frequency; calculating, via an induction motor inductance estimator, the motor's instantaneous reactive power and other intermediate quantities; and outputting the stator inductance and the total leakage factor. | 04-26-2012 |
| 20130009590 | METHOD AND DEVICE FOR OPERATING AN ASYNCHRONOUS MOTOR WITH INCREASED EFFICIENCY - Method and device for operating an asynchronous motor having increased efficiency. According to the invention, ranges for a motor size of the asynchronous motor are specified. In addition, a value of the motor size is calculated depending on at least one measurement value of a measurement parameter during the operation of the asynchronous motor, wherein the respective calculated value of the motor size is allocated to one of the ranges. Furthermore, a control parameter is changed depending on the range to which the calculated motor parameter is allocated to provide an optimised control parameter such that the control parameter is changed beginning from a starting value specified for the respective range of the motor size until a predetermined criterion for a specific motor size is reached. Furthermore, the optimised control parameter is stored as a support point of a continuous optimal characteristic curve for the control parameter depending on the range to which the calculated motor size is allocated. | 01-10-2013 |
| 20130043823 | CONTROL DEVICE FOR AN ASYNCHRONOUS ELECTRIC MACHINE, ELECTRIC PROPULSION SYSTEM COMPRISING SAID DEVICE, AND METHOD FOR CONTROLLING AN ASYNCHRONOUS ELECTRIC MACHINE - A control device for an asynchronous electric machine comprises a first computing unit configured for defining a first signal, which is correlated to an operating voltage to be applied to the electric machine. The first signal is defined as a function of a second signal indicating a desired stator frequency of the operating voltage, and as a function of a third signal indicating a desired slip frequency of the electric machine. | 02-21-2013 |
| 20130271060 | Motor Winding Heater Systems and Methods - A motor controller includes a motor winding heater function. The motor controller applies a predefined current to one or more of the motor windings without the use of additional dedicated motor winding heater devices. The motor controller serves to control the operation of the motor, while the motor windings serve both as a heater at times and to produce torque at times. | 10-17-2013 |
| 20140015468 | METHODS, SYSTEMS AND APPARATUS FOR ADJUSTING CURRENT AND/OR TORQUE COMMANDS USED TO CONTROL OPERATION OF AN ASYNCHRONOUS MACHINE - Embodiments of the present disclosure relate to methods, systems and apparatus for adjusting current and/or torque commands used to control operation of an asynchronous machine based on rotor flux of the asynchronous machine. | 01-16-2014 |
| 20140070755 | METHODS AND APPARATUSES FOR CONTROLLING OUTPUT VOLTAGES OF INVERTERS DRIVING ELECTRIC MOTORS - A method of controlling an output voltage of an inverter driving an electric motor may include calculating a current total harmonic distortion (THD) of a current output to the electric motor; comparing the current THD with a reference current THD; determining a pulse width modulation (PWM) method to be changed from a first modulation method that reduces harmonic components of the current output to the electric motor to a second modulation method when the current THD is less than the reference current THD, the PWM method modulating a pulse width of a control pulse signal for controlling the output voltage of the inverter; and/or generating the control pulse signal based on the determined PWM method. | 03-13-2014 |
| 20140132200 | 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 to calculate stator resistance therefrom. | 05-15-2014 |
| 20140167674 | SYSTEM FOR DETERMINING A MAGNETIZING CURVE AND ROTOR RESISTANCE OF AN INDUCTION MACHINE AND METHOD OF MAKING SAME - A system for identifying magnetizing inductance and rotor resistance of an induction machine comprises an induction machine comprising a rotor and a stator, a DC voltage bus, and a DC-to-AC voltage inverter coupled to the DC voltage bus and to the induction machine. The system also comprises a controller configured to cause the DC-to-AC voltage inverter to apply a square-wave excitation to a plurality of phases of the induction machine, determine a stator resistance of the stator of the induction machine based on the square-wave excitation, and determine a rotor resistance of the rotor of the induction machine based on the square-wave excitation. The controller is also configured to calculate a magnetizing curve for the induction machine based on the stator and rotor resistances and control the induction machine to operate based on the magnetizing curve. | 06-19-2014 |
| 20140184135 | SYSTEM AND METHOD FOR COMPENSATING FOR HIGH FREQUENCY APPLICATION OF RIPPLE CORRELATION TO MINIMIZE POWER LOSSES IN INDUCTION MACHINES - A method for minimizing power losses in an alternating current (AC) machine is provided. The method includes determining a first rotor flux signal based on signals of voltage and current inputs to the AC machine, and extracting a ripple component of the rotor flux signal. The method further includes determining a power compensating value that corresponds to a stored energy value of the AC machine, determining a second rotor flux signal that serves to minimize power losses, and providing the second rotor flux signal to a power inverting unit that adjust accordingly the voltage and current input signals provided to the AC machine. | 07-03-2014 |
| 20140346999 | CONTROL DEVICE AND CONTROL METHOD - A control device for an induction motor that drives a vehicle includes an electronic control unit. The electronic control unit i) controls torque of the induction motor when an inverter that controls supply of electric current to the induction motor is in a locked state, so as to release the inverter from the locked state, ii) determines whether the inverter is in the locked state, iii) controls a slip frequency of the induction motor when it determines that the inverter is in the locked state, and iv) superimposes a frequency that actual torque does not substantially respond, on the slip frequency, so that an electric frequency lies in a region outside a lock region in which the inverter is in the locked state. | 11-27-2014 |
| 20140354210 | CONTROL DEVICE AND CONTROL METHOD FOR VEHICULAR POWER SYSTEM - A control device for a vehicular power system including an induction motor includes an electronic control unit configured to detect a locked state of the induction motor, calculate a lock-release slip frequency that causes an electric frequency to be outside a lock range, and control the induction motor so that a slip frequency of the induction motor becomes equal to the lock-release slip frequency when the locked state is detected. | 12-04-2014 |
| 20150028792 | INDUCTION MOTOR FLUX AND TORQUE CONTROL - An induction motor controller is provided. The induction motor controller includes a first module that derives a commanded stator voltage vector, in a stator flux reference frame, via a rotor flux regulator loop and a torque regulator loop, which process at least partially in the stator flux reference frame. The induction motor controller includes a second module that processes the commanded stator voltage vector to produce AC (alternating current) power for an induction motor. | 01-29-2015 |
| 20160020717 | Direct Torque Control Motor Controller with Torque Ripple Reduction - An AC motor controller is provided that utilizes a direct torque controller and primary and secondary control loops. The primary control loop operates in a relatively conventional manner, determining a voltage vector that sets the inverter switching variables for the motor's power inverter, where the voltage vector is based on the motor's torque and flux as estimated from the measured voltage and current of the motor. The secondary loop, utilizing a faster sampling rate than the primary loop, estimates a more up-to-date torque error which is compared to a secondary torque error band, where the secondary torque error band is preferably narrower that the primary torque error band. If the secondary loop determines that the up-to-date torque error has exceeded the secondary torque error band, it sets a null voltage vector, thereby limiting torque ripples. | 01-21-2016 |
| 20160020718 | Direct Torque Control Motor Controller with Transient Current Limiter - An AC motor controller is provided that utilizes a direct torque controller and primary and secondary control loops. The primary control loop operates in a relatively conventional manner, determining a voltage vector that sets the inverter switching variables for the motor's power inverter, where the voltage vector is based on the motor's torque and flux as estimated from the measured voltage and current of the motor. The voltage vector determined by the primary loop is selected and applied immediately upon completion of the corresponding primary control loop computational cycle. The secondary loop, utilizing a faster sampling rate than that of the primary loop, compares the measured phase current to a preset current limit. If the secondary loop determines that the measured phase current has exceeded the preset current limit, it sets a null voltage vector, thereby limiting transient over currents. | 01-21-2016 |
| 20160020719 | Direct Torque Control Motor Controller with Transient Current Limiter - An AC motor controller is provided that utilizes a direct torque controller and primary and secondary control loops. The primary control loop operates in a relatively conventional manner, determining a voltage vector that sets the inverter switching variables for the motor's power inverter, where the voltage vector is based on the motor's torque and flux as estimated from the measured voltage and current of the motor. Application of the voltage vector determined by the primary loop is delayed until initiation of the next primary control loop cycle. The secondary loop, utilizing a faster sampling rate than that of the primary loop, compares the measured phase current to a preset current limit. If the secondary loop determines that the measured phase current has exceeded the preset current limit, it sets a null voltage vector, thereby limiting transient over currents. | 01-21-2016 |
| 20160181959 | CONTROL SYSTEM USING FLUX FEEDBACK | 06-23-2016 |
| 20160380576 | CONTROL DEVICE - Object of the present disclosure is to improve accuracy of over-temperature protection of an electric motor. A control device controls an inverter main circuit for driving the electric motor. An electric power conversion circuit controller acquires DC voltage input to the inverter main circuit, output voltage of the inverter main circuit, motor amperage of current flowing through the electric motor, and motor frequencies indicating rotation rate of the electric motor. Based on at least one of the DC voltage, output voltage, motor amperage and motor frequencies, a motor loss estimator calculates a stator loss and rotor loss, each including fundamental and harmonic losses of the electric motor. Based on the inverter output voltage, stator loss and rotor loss, the electric power conversion circuit controller outputs an actual control value for control of the inverter main circuit. | 12-29-2016 |
