Abstract: A controller in a motor control device includes an integral operation unit 606A (608A) that performs an arithmetic operation for a d(q)-axis integrated value Id** (Iq**) through integral control performed on a d(q)-axis current deviation ?Id (?Iq) and is configured to perform an arithmetic operation for a d(q)-axis voltage command value for controlling an output voltage of an inverter of a three-phase brushless motor. The controller further includes a limit value arithmetic operation unit 606C (608C) that performs an arithmetic operation for d(q)-axis integration upper and lower limit values Idmax (Iqmax) and Idmin (Iqmin) on the basis of a power source voltage of the inverter and the like and an integration limiting unit 606D (608E) that limits Id** (Iq**) within a predetermined range defined by the d(q)-axis integration upper and lower limit values.

Abstract: There are provided a brushless motor control device and a brushless motor control method that can suppress occurrence of step-out caused by reverse rotation, in low-speed sensorless control of a brushless motor. The brushless motor control device applies, to a brushless motor, a positive pulse generating torque in a rotation direction of the brushless motor and a negative pulse generating torque in a reverse rotation direction, and detects a rotation direction by using a magnetic saturation voltage generated when the positive and negative pulses are applied. The control device sets an upper limit value to a motor application duty represented by a value obtained by subtracting an application duty of the negative pulse from an application duty of the positive pulse.

Abstract: A three-phase brushless motor control device uses one shunt resistor disposed on a bus of an inverter as a drive circuit driving a three-phase brushless motor and acquires a two-phase current of the three-phase brushless motor at a predetermined timing to vector-control the three-phase brushless motor. At this time, in accordance with a duration in which the two-phase current cannot be accurately acquired, the control device varies an acquisition timing of the two-phase current or varies a period during which the three-phase brushless motor is vector-controlled.

Abstract: A three-phase brushless motor control device uses one shunt resistor disposed on a bus of an inverter as a drive circuit driving a three-phase brushless motor and acquires a two-phase current of the three-phase brushless motor at a predetermined timing to vector-control the three-phase brushless motor. At this time, in accordance with a duration in which the two-phase current cannot be accurately acquired, the control device varies an acquisition timing of the two-phase current or varies a period during which the three-phase brushless motor is vector-controlled.

Abstract: A controller in a motor control device includes an integral operation unit 606A (608A) that performs an arithmetic operation for a d(q)-axis integrated value Id** (Iq**) through integral control performed on a d(q)-axis current deviation ?Id (?Iq) and is configured to perform an arithmetic operation for a d(q)-axis voltage command value for controlling an output voltage of an inverter of a three-phase brushless motor. The controller further includes a limit value arithmetic operation unit 606C (608C) that performs an arithmetic operation for d(q)-axis integration upper and lower limit values Idmax (Iqmax) and Idmin (Iqmin) on the basis of a power source voltage of the inverter and the like and an integration limiting unit 606D (608E) that limits Id** (Iq**) within a predetermined range defined by the d(q)-axis integration upper and lower limit values.

Abstract: To enable overmodulation control having high controllability and low noise characteristics, a control device of an AC motor includes an inverter for driving an AC motor and a controller for controlling the inverter by pulse width modulation. The controller, when over-modulating the inverter, limits the amplitude of the voltage command in the pulse width modulation to a predetermined upper limit value or less.

Abstract: A motor control device drives a motor provided as a drive source of an electric actuator by performing vector control using d-q rotational coordinates, and sets a d-axis current command value so as to weaken field flux of the motor when torque is applied to the motor from the exterior in a direction that is the same as a rotation direction of the motor. When the rotational speed of the motor exceeds the predetermined upper rotational speed limit, the motor control device calculates a correction amount of the d-axis current command value so as to make a rotational speed of the motor converge to a predetermined upper rotational speed limit, and corrects the d-axis current command value by this correction amount.

Abstract: A motor control device drives a motor provided as a drive source of an electric actuator by performing vector control using d-q rotational coordinates, and sets a d-axis current command value so as to weaken field flux of the motor when torque is applied to the motor from the exterior in a direction that is the same as a rotation direction of the motor. When the rotational speed of the motor exceeds the predetermined upper rotational speed limit, the motor control device calculates a correction amount of the d-axis current command value so as to make a rotational speed of the motor converge to a predetermined upper rotational speed limit, and corrects the d-axis current command value by this correction amount.

Abstract: An abnormality diagnostic unit of a motor drive device has an inverter that supplies AC power to an electric motor, and a current measuring means for measuring a DC bus current of the inverter, calculates an estimated upper q-axis current limit and an estimated lower q-axis current limit based on a diagnostic q-axis voltage command value obtained by subjecting a q-axis voltage command value to an absolute value process. The abnormality diagnostic unit calculates a diagnostic q-axis current measurement based on: a q-axis current measurement calculated based on an output of the current measuring means; and sign information of the q-axis voltage command value. Then, the abnormality diagnostic unit determines whether the current measuring means is abnormal based on duration of deviation of the diagnostic q-axis current measurement from a normal range defined by the estimated upper q-axis current limit and the estimated lower q-axis current limit.

Abstract: The drive device measures an open-phase voltage in an energization period in pulse width modulation control, and estimates position information of a rotor based on the measured voltage value, to drive the three-phase brushless motor. This drive device is configured so that, when a voltage pulse width of a set duty cycle is less than or equal to a predetermined value, energization with a voltage pulse width of a minimum duty cycle is performed twice in one period of pulse width modulation, and energization with a voltage pulse width of a correction duty cycle is performed twice in next one period of the pulse width modulation, so that energization with a voltage pulse width of a drive duty cycle corresponding to the set duty cycle is performed, on average in two periods.

Abstract: The drive device measures an open-phase voltage in an energization period in pulse width modulation control, and estimates position information of a rotor based on the measured voltage value, to drive the three-phase brushless motor. This drive device is configured so that, when a voltage pulse width of a set duty cycle is less than or equal to a predetermined value, energization with a voltage pulse width of a minimum duty cycle is performed twice in one period of pulse width modulation, and energization with a voltage pulse width of a correction duty cycle is performed twice in next one period of the pulse width modulation, so that energization with a voltage pulse width of a drive duty cycle corresponding to the set duty cycle is performed, on average in two periods.

Abstract: A drive apparatus and a drive method for a brushless motor, capable of reducing noise occurring due to pulse shift processing, is provided. The drive apparatus for the brushless motor comprises one shunt resistor and a controller. The shunt resistor measures a phase current of the three-phase brushless motor. The controller measures the phase current of the brushless motor in a one-shunt system by using the shunt resistor, and controls driving of the brushless motor based on the measured phase current. The controller performs pulse shift when a voltage pulse width in a drive wire of the brushless motor is greater than a predetermined value, whereas the controller does not perform the pulse shift when the voltage pulse width is less than the predetermined value.

Abstract: A control device of a synchronous electric motor includes: the synchronous electric motor with three-phase stator windings Y-connected; a detection unit that detects a neutral point potential which is a potential at a Y connection point; and an inverter that drives the synchronous electric motor. The control device of the synchronous electric motor which controls the synchronous electric motor using the inverter, includes a measurement mode in which the neutral point potential is detected in a state in which the synchronous electric motor is energized by an AC current and controls the synchronous electric motor based on a value of the neutral point potential detected in the measurement mode.

Abstract: An abnormality diagnostic unit of a motor drive device has an inverter that supplies AC power to an electric motor, and a current measuring means for measuring a DC bus current of the inverter, calculates an estimated upper q-axis current limit and an estimated lower q-axis current limit based on a diagnostic q-axis voltage command value obtained by subjecting a q-axis voltage command value to an absolute value process. The abnormality diagnostic unit calculates a diagnostic q-axis current measurement based on: a q-axis current measurement calculated based on an output of the current measuring means; and sign information of the q-axis voltage command value. Then, the abnormality diagnostic unit determines whether the current measuring means is abnormal based on duration of deviation of the diagnostic q-axis current measurement from a normal range defined by the estimated upper q-axis current limit and the estimated lower q-axis current limit.

Abstract: A drive apparatus and a drive method for a brushless motor, capable of reducing noise occurring due to pulse shift processing, is provided. The drive apparatus for the brushless motor comprises one shunt resistor and a controller. The shunt resistor measures a phase current of the three-phase brushless motor. The controller measures the phase current of the brushless motor in a one-shunt system by using the shunt resistor, and controls driving of the brushless motor based on the measured phase current. The controller performs pulse shift when a voltage pulse width in a drive wire of the brushless motor is greater than a predetermined value, whereas the controller does not perform the pulse shift when the voltage pulse width is less than the predetermined value.

Abstract: The present invention provides a control device and a control method for a brushless motor, including energization modes for selecting a phase to be energized by pulse width modulation operation from among phases of the brushless motor, and being provided for controlling the rotation speed of the brushless motor by switching between the energization modes based on comparison of a voltage induced in a non-energized phase with its threshold value. In the control device and method, the input voltage of the brushless motor is increased when the duration for which the induced voltage is maintained unchanged or the duration for which the current energization mode is maintained employed reaches a predetermined time. This prevents the brushless motor from being staying in the stopped state, even when the load on the brushless motor abruptly increases while the brushless motor rotates at a speed within an extremely low speed range.

Abstract: To enable overmodulation control having high controllability and low noise characteristics, a control device of an AC motor includes an inverter for driving an AC motor and a controller for controlling the inverter by pulse width modulation. The controller, when over-modulating the inverter, limits the amplitude of the voltage command in the pulse width modulation to a predetermined upper limit value or less.

Abstract: The present invention relates to a motor drive device and a phase current detecting method for a three-phase brushless motor, and more particularly to a technique of detecting each phase current through A/D conversion that is carried out once per PWM carrier cycle, by use of a current sensor for detecting a DC bus current of an inverter. The control unit of the present invention calculates a phase current for one phase, an absolute phase current value of which becomes maximum at a detection timing that is set once per PWM control cycle, from an output of the current sensor, and estimates phase currents for the remaining two phases based on a peak value of a phase current detected at each detection timing, a motor angle, and a phase shift of an actual phase current waveform relative to the motor angle.

Abstract: The present invention provides a control device and a control method for a brushless motor, including energization modes for selecting a phase to be energized by pulse width modulation operation from among phases of the brushless motor, and being provided for controlling the rotation speed of the brushless motor by switching between the energization modes based on comparison of a voltage induced in a non-energized phase with its threshold value. In the control device and method, the input voltage of the brushless motor is increased when the duration for which the induced voltage is maintained unchanged or the duration for which the current energization mode is maintained employed reaches a predetermined time. This prevents the brushless motor from being staying in the stopped state, even when the load on the brushless motor abruptly increases while the brushless motor rotates at a speed within an extremely low speed range.

Abstract: A control device of a synchronous electric motor includes: the synchronous electric motor with three-phase stator windings Y-connected; a detection unit that detects a neutral point potential which is a potential at a Y connection point; and an inverter that drives the synchronous electric motor. The control device of the synchronous electric motor which controls the synchronous electric motor using the inverter, includes a measurement mode in which the neutral point potential is detected in a state in which the synchronous electric motor is energized by an AC current and controls the synchronous electric motor based on a value of the neutral point potential detected in the measurement mode.