An apparatus according to the aspect of the embodiments includes a phase determiner configured to determine a rotational phase of a rotor, a speed determiner configured to determine a rotational speed of the rotor, a controller having a first control mode for controlling the motor by supplying constant currents to windings, and a discriminator configured to discriminate whether a rotation of the motor is abnormal based on the rotational speed when the rotational speed corresponding to a command speed is equal to or higher than a predetermined value in a state where the controller is controlling the motor in the first control mode. When a signal output from the discriminator indicates that the rotation of the motor is abnormal, the controller stops the motor. When the signal output from the discriminator indicates that the rotation is not abnormal, the controller continues a drive of the motor.

A method of driving a permanent magnet synchronous motor (PMSM) with Field Oriented Control (FOC) includes: generating, by a current controller, control signals for driving motor currents of the PMSM; measuring, by the current controller, current information of the PMSM, including a direct-axis motor current and a quadrature-axis motor current; generating, by a direct-axis current controller, a direct-axis error value based on a difference between a flux weakening reference current and the direct-axis motor current; regulating, by the direct-axis current controller, a direct-axis motor voltage, including generating the direct-axis motor voltage based on the direct-axis error value; and generating and dynamically adapting, by a flux weakening controller, the flux weakening reference current based on changes to the motor load.

In some embodiments, a system of controlling an induction electric motor, includes a command voltage output unit for generating a command voltage for operating an inverter according to a command speed and outputting the generated command voltage to the inverter; a control unit for controlling the command voltage output unit such that the command voltage output to the inverter is compared with an operation limiting voltage and the command voltage is corrected to fall within the operation limiting voltage; and the inverter for controlling the induction electric motor depending on the corrected command voltage. Thus, it is possible to precisely control the induction electric motor even in a high speed operation region by regulating the magnitude of the command voltage applied to the induction electric motor by means of dynamic modulation strategies without the magnetic flux controller.

In some embodiments, a system of controlling an induction electric motor, includes a command voltage output unit for generating a command voltage for operating an inverter according to a command speed and outputting the generated command voltage to the inverter; a control unit for controlling the command voltage output unit such that the command voltage output to the inverter is compared with an operation limiting voltage and the command voltage is corrected to fall within the operation limiting voltage; and the inverter for controlling the induction electric motor depending on the corrected command voltage. Thus, it is possible to precisely control the induction electric motor even in a high speed operation region by regulating the magnitude of the command voltage applied to the induction electric motor by means of dynamic modulation strategies without the magnetic flux controller.

A motor device configured to convey a fluid by driving a fan with a motor includes a position/speed acquirer configured to acquire a current rotation angle and a current rotation speed of the motor, a multiplier configured to calculate a flow-rate-constant target driving current by multiplying the rotation speed and a flow rate coefficient, and a current controller configured or programmed to control a motor driving current by setting, as a control target, the flow-rate-constant target driving current and to control a flow rate of the fluid to be maintained at a constant value which depends on the flow rate coefficient.

A motor device configured to convey a fluid by driving a fan with a motor includes a position/speed acquirer configured to acquire a current rotation angle and a current rotation speed of the motor, a multiplier configured to calculate a flow-rate-constant target driving current by multiplying the rotation speed and a flow rate coefficient, and a current controller configured or programmed to control a motor driving current by setting, as a control target, the flow-rate-constant target driving current and to control a flow rate of the fluid to be maintained at a constant value which depends on the flow rate coefficient.

The present invention relates to a motor drive apparatus and, more particularly, to a motor drive apparatus capable of immediately restarting by maintaining sensorless control during a stop operation of a motor. The motor drive apparatus comprises: an inverter for driving a motor by using an AC voltage; and a control unit for controlling operations of a switching element included in the inverter. At this time, when a stop command is input, the control unit decreases a duty ratio of a PWM signal until a present speed of the motor becomes smaller than a predetermined minimum speed, thereby decreasing the revolutions per minute of the motor. Then, when a restart command is input in a state where the duty ratio of the PWM signal is decreased, the control unit can immediately restart the motor by increasing the duty ratio of the PWM signal.

A drive control apparatus for multiple-winding motor includes: a modulation rate phase command generation unit which calculates currents of first and second inverters for driving a multiple-winding three-phase motor and generates a modulation rate command and a phase command for equalizing the currents; a pulse number determination unit which determines the number of pulses per half cycle on the basis of a frequency command; a pattern table for storing switching patterns; and gate signal generators which control the first and second inverters, using an optimal switching pattern based on the number of pulses, wherein the modulation rate phase command generation unit performs control for equalizing currents of the first and second inverters, and the phase or frequency at which the control is performed is changed in accordance with any of the number of pulses, the modulation rate, the frequency command, and the switching pattern.

An inverter controller is used to control an inverter circuit that drives an electric motor including a rotor and a stator. The inverter controller includes a voltage detector configured to detect input voltage, a current detector configured to detect motor current, an instruction value calculation unit configured to calculate an instruction value based on an external instruction value and a detection result of the current detector, a correction unit configured to calculate a corrected instruction value by correcting the instruction value in accordance with the input voltage, a PWM control unit configured to control the motor current based on the corrected instruction value and the input voltage, and a position estimation unit configured to estimate a rotation position of the rotor based on the instruction value and the detection result of the current detector.

Disclosed is a vector flux weakening control method for vector flux weakening for a vehicle permanent magnet synchronous motor, which includes a current closed-loop adjuster, a modulation ratio deviation calculator, a current command angle compensator, a current angle preset processor, a current command angle limiting comparator and a current given vector corrector. The adjusting direction of the present disclosure is always a flux weakening direction, and instability caused by repeated adjustment will not occur; by introducing dq current while performing correction, the pressure against voltage saturation can be shared to both d-axis and q-axis current, so as to avoid excessive output torque deviation caused by excessive adjustment of a single-axis current; the influence of the flux weakening control link on the output torque of the drive system can be minimized as much possible while ensuring the safety of the drive system.