Abstract: To prevent a step-out of a permanent magnet synchronous type motor (1), a motor control device (3a) is provided to include a flux control unit (16) for deriving an excitation current command value (i?*) according to the rotation speed (?e) of the motor, and a voltage shortage determination unit (30) for determining whether or not the supply voltage to the motor is running short based on the excitation current command value (i?*). When a negative excitation current command value (i?*) is smaller than a negative determination threshold value, the motor control device determines that the supply voltage is running short and prohibits an increase of the rotation speed or decreases the rotation speed.

Abstract: A motor control device includes an estimator for estimating a rotor position of a motor having a salient pole by using a value corresponding to a q-axis inductance of the motor as an operation parameter where an estimated axes for the control corresponding to d-q axes are ?-? axes, and a controller for controlling the motor based on the estimated rotor position. The estimator generates a deviation between a d-axis and a ?-axis by performing the estimation of the rotor position based on a value between a real q-axis inductance and a real d-axis inductance of the motor adopted as the operation parameter. The controller controls the motor so that a ?-axis component of a motor current supplied to the motor is maintained to be a predetermined value of zero or close to zero regardless of a value of a ?-axis component of the motor current.

Abstract: A motor control device includes a motor current detector for detecting motor current flowing in a three-phase motor based on current flowing between an inverter driving the motor and a DC power supply, a specified voltage vector generating portion for generating a specified voltage vector indicating a voltage vector to which an applied voltage to the motor should follow based on a magnetic flux linkage of an armature winding of the motor, a specified voltage vector correcting portion for correcting the generated specified voltage vector, and a magnetic flux estimating portion for estimating the magnetic flux linkage based on the motor current and the specified voltage vector after the correction. The motor control device controls the motor via the inverter in accordance with the specified voltage vector after the correction.

Abstract: The motor control device includes a current detecting portion for detecting a phase current that flows in an armature winding of a stator of a three-phase motor based on current that flows between an inverter for driving the motor and a DC power supply. The motor control device performs a position sensorless vector control for the motor based on a control current that is obtained by a three-phase to two-phase conversion of the phase current based on an estimated rotor position of the motor. The motor control device farther includes a superposing portion for superposing a superposed voltage having a predetermined frequency on a drive voltage for driving the motor and an estimating portion for deriving the estimated rotor position based on the superposed current that is extracted from the control current and flows in the motor in accordance with the superposed voltage. A voltage vector locus of the superposed voltage from the superposing portion presents an ellipse.

Abstract: Let an axis parallel to a magnetic flux produced by a permanent magnet provided on a rotor of a motor be called a d-axis, let an axis leading the d-axis by an electrical angle of 90 degrees be called a q-axis, and let control axes corresponding to the d-axis and the q-axis be called a ?-axis and a ?-axis, respectively. Then, a motor control device performs vector control of the motor with the ?-axis and the ?-axis made different from the d-axis and the q-axis, respectively, and with a motor current passing through the motor broken down into a ?-axis current on the ?-axis and a ?-axis current on the ?-axis.

Abstract: In a motor driving control device, a high-frequency alternating voltage or rotation voltage (having a frequency of ?h) is applied to a motor so that magnetic saturation occurs in the motor, thereby extracting, from a ?-axis current, a high-frequency second-harmonic component (a frequency component of 2×?h) that is obtained by attenuating at least a direct-current component of the ?-axis current. The polarity checker detects the polarity of the magnetic pole of the rotor based on the difference, caused by magnetic saturation, between the positive and negative amplitudes of the high-frequency second-harmonic component.

Abstract: The motor control device includes a current detecting portion for detecting a phase current that flows in an armature winding of a stator of a three-phase motor based on current that flows between an inverter for driving the motor and a DC power supply. The motor control device performs a position sensorless vector control for the motor based on a control current that is obtained by a three-phase to two-phase conversion of the phase current based on an estimated rotor position of the motor. The motor control device farther includes a superposing portion for superposing a superposed voltage having a predetermined frequency on a drive voltage for driving the motor and an estimating portion for deriving the estimated rotor position based on the superposed current that is extracted from the control current and flows in the motor in accordance with the superposed voltage. A voltage vector locus of the superposed voltage from the superposing portion presents an ellipse.

Abstract: An object is to provide a driving device capable of smoothly shifting from a starting state to a sensor-less vector control, in a case where the device drives a motor by the sensor-less vector control, and the device includes a voltage detecting circuit which detects an induced electromotive voltage of the motor. A control circuit starts the motor by rectangular wave control. A magnetic pole position of a rotor is detected based on an induced electromotive voltage of one remaining phase of the motor detected by the voltage detecting circuit. The control circuit controls a main inverter circuit based on the detected magnetic pole position, and accelerates the motor by the rectangular wave control. In a case where a predetermined shift revolution speed is reached, the control circuit shifts to vector control by the sensor-less in which the magnetic pole position detected during the rectangular wave control is used as an initial value.

Abstract: A motor control device includes a current detecting portion that detects current flowing between an inverter for driving a three-phase motor and a DC power supply for supplying DC voltage to the inverter, a current estimator that estimates a current vector of the motor on a rotating coordinate that rotates along with rotation of a rotor of the motor. The motor control device detects motor current flowing in the motor by using one of a detecting result of the current detecting portion and an estimation result of the current estimator, so as to control the motor via the inverter based on the detected motor current. The current estimator estimates the current vector based on the motor current detected in the past and a specified voltage value, for example.

Abstract: A current detecting unit detects three phase current of a three-phase inverter from current flowing between the inverter and a DC power supply. The current detecting unit includes a specified voltage vector generating portion that generates a specified voltage vector indicating a voltage vector that three-phase voltage of the inverter should follow, and a specified voltage vector correcting portion that corrects the generated specified voltage vector. The inverter is controlled in accordance with the specified voltage vector after the correction.

Abstract: A motor control device that controls a permanent-magnet synchronous motor has: a magnetic flux controller that derives, as a specified excitation current value, a specified current value corresponding to a d-axis component of a current passing through an armature winding; and a current controller that controls, based on the specified excitation current value, the current passing through the armature winding. The magnetic flux controller makes the specified excitation current value vary periodically, based on an estimated or detected rotor position, in a current range in which the magnetic flux produced by the permanent magnet is weakened, and changes the specified excitation current value according to a rotation speed of the rotor.

Abstract: Let the rotating axis whose direction coincides with the direction of the current vector that achieves maximum torque control be called the qm-axis, and the rotating axis perpendicular to the qm-axis be called the dm-axis. A motor control device switches its operation between low-speed sensorless control and high-speed sensorless control according to the rotation speed of the rotor. In low-speed sensorless control, the magnetic salient pole of the motor is exploited, and the d-q axes are estimated by, for example, injection of a high-frequency rotating voltage. In high-speed sensorless control, the dm-qm axes are estimated based on, for example, the induction voltage produced by the rotation of the rotor. During high-speed sensorless control, the ?(dm)-axis current is kept at zero irrespective of the ?(qm)-axis current.

Abstract: A motor control device that includes a first speed estimator estimating the rotation speed of the rotor of a permanent-magnet synchronous motor and that controls the motor so that a first estimated rotation speed estimated by the first speed estimator follows the specified speed value further includes a second speed estimator that estimates the rotation speed of the rotor by an estimation method different from that used by the first speed estimator. The motor control device detects synchronization failure based on a comparison between a second estimated rotation speed estimated by the second speed estimator and the first estimated rotation speed or the specified speed value.

Abstract: 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 current fed to the motor, the ?-axis and ?-axis components of the superposed current, and a controller that controls the motor so that the direct-current component of the arithmetic product of the extracted ?-axis and ?-axis components of the superposed current converges to zero.

Abstract: In a motor driving control device, a high-frequency alternating voltage or rotation voltage (having a frequency of ?h) is applied to a motor so that magnetic saturation occurs in the motor, thereby extracting, from a ?-axis current, a high-frequency second-harmonic component (a frequency component of 2×?h) that is obtained by attenuating at least a direct-current component of the ?-axis current. The polarity checker detects the polarity of the magnetic pole of the rotor based on the difference, caused by magnetic saturation, between the positive and negative amplitudes of the high-frequency second-harmonic component.

Abstract: An object is to provide a driving device capable of smoothly shifting from a starting state to a sensor-less vector control, in a case where the device drives a motor by the sensor-less vector control, and the device includes a voltage detecting circuit which detects an induced electromotive voltage of the motor. A control circuit starts the motor by rectangular wave control. A magnetic pole position of a rotor is detected based on an induced electromotive voltage of one remaining phase of the motor detected by the voltage detecting circuit. The control circuit controls a main inverter circuit based on the detected magnetic pole position, and accelerates the motor by the rectangular wave control. In a case where a predetermined shift revolution speed is reached, the control circuit shifts to vector control by the sensor-less in which the magnetic pole position detected during the rectangular wave control is used as an initial value.

Abstract: A motor control device includes an estimator for estimating a rotor position of a motor having a salient pole by using a value corresponding to a q-axis inductance of the motor as an operation parameter where an estimated axes for the control corresponding to d-q axes are ?-? axes, and a controller for controlling the motor based on the estimated rotor position. The estimator generates a deviation between a d-axis and a ?-axis by performing the estimation of the rotor position based on a value between a real q-axis inductance and a real d-axis inductance of the motor adopted as the operation parameter. The controller controls the motor so that a ?-axis component of a motor current supplied to the motor is maintained to be a predetermined value of zero or close to zero regardless of a value of a ?-axis component of the motor current.

Abstract: 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 current fed to the motor, the ?-axis and ?-axis components of the superposed current, and a controller that controls the motor so that the direct-current component of the arithmetic product of the extracted ?-axis and ?-axis components of the superposed current converges to zero.

Abstract: A device for controlling a brushless motor including an inverter for supplying a.c. electric power to the motor, and a drive control circuit for controlling the inverter. The control circuit includes a load weight detecting circuit for detecting the load weight acting on the motor, a circuit for preparing a driving signal, and a circuit for preparing a PWM signal based on the driving signal. The driving signal preparing circuit derives from the load weight detected a phase reference value to give a phase difference of up to 90 degrees between the braking voltage to be applied to the motor and the current of the motor, and prepares the based on the phase reference value.

Abstract: A device of the invention for controlling a brushless motor comprises an inverter 43 for supplying a.c. electric power to the motor 3, and a drive control circuit 5 for controlling the inverter 43. The control circuit 5 comprises a load weight detecting circuit 53 for detecting the load weight acting on the motor 3, a circuit 54 for preparing a driving signal, and a circuit 55 for preparing a PWM signal based on the driving signal. The driving signal preparing circuit 54 derives from the load weight detected a phase reference value to give a phase difference of up to 90 degrees between the braking voltage to be applied to the motor 3 and the current of the motor 3, and prepares the based on the phase reference value.