Patent application number | Description | Published |
20080309268 | Initial Pole Position Estimating Apparatus and Method for Ac Synchronous Motor - The present invention provides an initial pole position estimating apparatus and method for an AC synchronous motor without using magnetic pole detector. The initial pole position estimating apparatus includes a thrust force or torque pattern generating portion for generating a thrust force or torque pattern, a pole position command generating portion for generating a pole position command, and a position detecting portion for detecting a position of the AC synchronous motor. The initial pole position estimating apparatus can estimate an initial pole position in a short time with high precision without depending on a fluctuation in a load. The initial pole position estimating apparatus further includes a pole position correcting portion ( | 12-18-2008 |
20100079103 | ALTERNATING-CURRENT MOTOR CONTROL APPARATUS - An alternating-current motor control apparatus includes a stator frequency computing unit configured to compute a stator frequency of a motor magnetic flux; a torque error computing unit configured to compute a torque error by using the motor magnetic flux, an estimated current, and a motor current; and a speed estimator configured to estimate a speed of the alternating-current motor by using the stator frequency and the torque error. The speed estimator includes a proportional controller configured to reduce the torque error to zero, and an adaptive filter configured to eliminate a high-frequency component of the torque error. | 04-01-2010 |
20100207555 | ALTERNATING-CURRENT MOTOR CONTROL APPARATUS - An alternating-current motor control apparatus includes a voltage controller configured to output a command voltage vector so that the command voltage vector is time-averaged for time periods, a square-wave voltage generator configured to control, every time period, amplitudes and phases of voltages to be applied to an alternating-current motor, a current detector configured to detect motor currents at a timing synchronized with periods 1/N-th of the time periods, where N is equal to or larger than one, a coordinate transformation section configured to perform coordinate transformation to transform the motor currents into two-phase currents, an envelope extractor configured to extract two-phase currents as waveforms having amplitudes that periodically change from the two-phase currents, and extract envelopes of the waveforms, and a magnetic-pole-position computing section configured to compute a magnetic-pole position using the envelopes. | 08-19-2010 |
20100219780 | MOTOR CONTROL APPARATUS - A motor control apparatus includes a current control unit which is configured to calculate dq-axis voltage commands to match d-axis and q-axis current commands with d-axis and q-axis currents of a motor current, respectively. A power conversion circuit is configured to drive the motor. A modulation factor command unit is configured to determine a modulation factor command. A modulation wave command unit is configured to determine modulation wave commands. A pulse width modulation generating unit is configured to generate a pulse width modulation pattern. A modulation factor saturation level calculating unit is configured to determine a modulation factor saturation level. A field-weakening control unit is configured to correct the d-axis current command. | 09-02-2010 |
20100308757 | ALTERNATING-CURRENT MOTOR CONTROL APPARATUS - An alternating-current motor control apparatus includes an inverter unit, a current-command divider, a current controller, a torque-variation calculator, and a phase angle generator. The inverter unit is configured to output a command voltage to an alternating-current motor. The current-command divider is configured to divide a command current amplitude into command current components based on a phase-angle command value that is a sum of the phase angle and an alternating current signal. The current controller is configured to control current to match a motor current flowing through the motor with the command current components. The torque-variation calculator is configured to calculate a motor electric power based on the command voltage and either the motor current or the command current components and to calculate a torque variation based on the motor electric power. The phase angle generator is configured to generate a phase angle based on the torque variation. | 12-09-2010 |
20120319629 | INVERTER DEVICE AND CONTROL METHOD THEREOF - This inverter device includes a power portion performing PWM control on a voltage command to a motor for each set time period, converting direct-current power into alternating-current power, and outputting the same, a voltage command generation portion generating a voltage command in synchronization with a period N-times (N≧1) longer than the time period, an interval determination portion generating an interval determination signal which is ON during a half period of the time period and OFF during the next half period, a current detection portion detecting the current of the motor at timing of change in the interval determination signal, and a voltage correction portion generating a voltage correction value such that the amount of change in the detected current when the interval determination signal is ON becomes equal to the amount of change in the detected current when it is OFF and correcting the voltage command. | 12-20-2012 |
20140049202 | MOTOR CONTROL APPARATUS AND MOTOR CONTROL METHOD - A motor control apparatus according to the embodiment includes a rotational position estimating unit, a change amount estimating unit, and an inductance estimating unit. The rotational position estimating unit estimates a rotational position of a rotor from a motor parameter including a q-axis inductance of a motor on a basis of an output current to the motor and a voltage reference. The change amount estimating unit estimates a change amount of an output torque with respect to a current phase change of the motor corresponding to a high frequency signal whose frequency is higher than a drive frequency of the motor. The inductance estimating unit estimates an inductance value that obtains a maximum torque on a basis of the change amount as the q-axis inductance. | 02-20-2014 |
20140160824 | MATRIX CONVERTER AND METHOD FOR CONTROLLING MATRIX CONVERTER - A matrix converter according to an embodiment includes a plurality of bidirectional switches and a controller. The bidirectional switches connect each of phases of an alternating current (AC) power supply with each of phases of a rotary electric machine. The controller controls the bidirectional switches to perform power conversion control between the AC power supply and the rotary electric machine. The controller performs on/off control individually on a plurality of unidirectional switching elements constituting the bidirectional switches by using both 120-degree conduction control and PWM control. | 06-12-2014 |
20140176100 | MATRIX CONVERTER AND METHOD FOR CONTROLLING MATRIX CONVERTER - A matrix converter according to one aspect of an embodiment includes a plurality of bidirectional switches and a controller. The bidirectional switches connect each phase of an alternating current (AC) power supply with each phase of the rotary electric machine. The controller performs power conversion control between the AC power supply and the rotary electric machine by controlling a plurality of unidirectional switching elements constituting the bidirectional switches individually. The controller performs switching control for advancing the timing at which the unidirectional switching elements constituting the bidirectional switches are switched ON from that in 120-degree conduction control, and for extending a period for which the unidirectional switching elements are kept ON from that in the 120-degree conduction control. | 06-26-2014 |
20140246939 | MOTOR AND MOTOR SYSTEM - The motor includes: a rotor that includes a rotor core provided with a plurality of permanent magnets in a circumferential direction; and a stator that includes a stator core on which multi-phase stator coils are wound and is arranged facing the rotor with a predetermined air gap therebetween. The rotor has a structure in which the change pattern of magnetic properties of the rotor core or the permanent magnets changes stepwise in the circumferential direction. The stator has a structure in which the distribution pattern of a magnetic field generated by the stator coils with one phase or with a combination of the phases has uniqueness over a whole circumference. | 09-04-2014 |
20140246940 | MOTOR AND MOTOR SYSTEM - A motor includes a rotor including a rotor core provided with a plurality of permanent magnets in the circumferential direction and a stator including a stator core on which multi-phase stator coils are wound. The rotor has a structure in which the change pattern of magnetic properties of the rotor core or the permanent magnets changes in the circumferential direction, and the stator has a structure in which first and second stator coils of the stator coils are wound on the stator core for each phase in such a manner that passage of current is optionally switched, and when the passage of current is switched to the second stator coil, the distribution pattern of a magnetic field formed on the inner circumferential side by the stator has uniqueness over the whole circumference. | 09-04-2014 |
20140346984 | MAGNETIC POLE POSITION ESTIMATING APPARATUS FOR ELECTRIC MOTOR, CONTROLLING APPARATUS FOR ELECTRIC MOTOR, AND MAGNETIC POLE POSITION ESTIMATING METHOD FOR ELECTRIC MOTOR - A controlling apparatus for an electric motor according to an embodiment includes a superposed component generator, an inverter, a current detector, and a magnetic pole position estimator. The superposed component generator generates, at a predetermined cycle, a superposed voltage reference of which vector is shifted by 90 degrees with respect to that of a superposed voltage reference previously generated, in a coordinate system that is set to a stator of the electric motor. The inverter outputs a driving voltage that is based on a driving voltage reference superposed with the superposed voltage reference to the electric motor. The current detector detects currents flowing into respective phases of the electric motor, and outputs the detected currents. The magnetic pole position estimator detects the magnetic pole position of the electric motor based on an amount of change in the detected currents at the predetermined cycle. | 11-27-2014 |