To provide a controller for motor which can reduce a torque ripple up to high frequency, without amplifying unnecessary noise and vibration. A controller for motor estimates an interlinkage flux based on the applied voltage and the detection value of current; estimates an output torque based on the detection value of current and the estimation value of interlinkage flux; extracts a pulsation component from the estimation value of output torque; calculates a voltage command correction value based on the extraction value of pulsation component; calculates a voltage command after superimposing by superimposing the voltage command correction value on the voltage command basic value; and applies voltage to winding based on the voltage command after superimposing.

A riding lawn mower includes a running assembly, a power output assembly, a power supply device, a driver circuit, an operating device, and a control module. The running assembly includes running wheels and a first motor for driving the running wheels. The operating device is configured to set at least one of target torque or a target rotational speed of the first motor. The control module is configured to output a control signal to the driver circuit to make an input current or an input voltage of the first motor vary with a rotor position of the first motor and make an actual torque of the first motor reach or basically reach the target torque within a preset time.

A control system for motor configured to control currents supplied to an armature coil and a field coil properly to achieve a required torque. The control system controls torque of a rotor by controlling a base torque generated by energizing an armature coil, and a field torque generated by energizing a field coil. When a target torque is equal to or greater than a predetermined torque, the controller controls the base torque and the field torque such that a ratio of the field torque to the target torque is increased greater than that of a case in which the target torque is less than the predetermined torque.

An online method of detecting and compensating for errors in flux estimation in operation of a motor system. The method includes determining a voltage compensation term by comparing an expected voltage and an actual voltage. The method also includes determining a flux compensation term by passing the voltage compensation term through a low-pass filter, and determining a corrected flux component value by comparing the flux compensation term with a flux value obtained from a look-up table, wherein the low-pass filter receives operating parameters based on data regarding an operating environment of the motor system. The method then further determines a corrected torque value based on the corrected flux component value.

Reduced computation time for model predictive control (MPC) of a five level dual T-type drive considering the DC link capacitor balancing, the common-mode voltage (CMV) along with torque control of an open-ends induction motor based on determining a reduced set of switching states for the MPC. The reduced set of switching states are determined by considering either CMV reduction (CMVR) or CMV elimination (CMVE). Cost function minimization generates a voltage vector, which is used to produce gating signals for the converter switches. The reduced switching state MPC significantly reduces computation time and improves MPC performance.

A motor flux weakening control method with data map creation is provided. The method estimates a phase angle between a dq electric current vector and a d-axis based on a speed of the motor; estimates an input direct current; repeats the estimating of the phase angle and the direct current while decreasing a magnitude of the dq electric current vector based on a difference between the estimated direct current and a preset direct current limitation value; and interrupts the repeating of the estimating of the phase angle and the estimating of the direct current when the direct current and the preset direct current limitation value are equal, and stores a relationship between the speed of the motor, the direct current voltage, the phase angle, and the magnitude of the dq electric current vector, when the estimated direct current and the preset direct current limitation value are equal.

A control device and a control method for an induction motor. The control device comprises: a magnetizing current adjusting unit used for calculating a magnetizing voltage instruction; a torque current adjusting unit used for calculating a torque voltage instruction; a flux linkage instruction angle generating unit calculating a flux linkage instruction angle according to a lower limit ω.sub.1th of a preset stator frequency, a stator frequency ω.sub.1, and a flux linkage estimation angle; and a motor stator voltage instruction calculating unit calculating, according to the magnetizing voltage instruction, the torque voltage instruction, and the flux linkage instruction angle, a stator voltage instruction for controlling a stator of the motor. The control system can be run outside an unstable area, and the stability of control by the control device is improved.

A driving device of one embodiment includes a phase estimator and a voltage controller. The phase estimator estimates a phase of stator interlinkage magnetic flux of an electric motor based on a current flowing through the electric motor, a voltage command of a drive voltage applied to the electric motor, and a winding resistance value of the electric motor. The voltage controller acquires a first voltage vector component in a direction in which the stator interlinkage magnetic flux acts and a second voltage vector component in a direction which is orthogonal to the direction in which the stator interlinkage magnetic flux acts for the voltage command of the drive voltage, and sets the voltage command of the drive voltage based on the first voltage vector component and the second voltage vector component.

A method of switching from a closed-loop start-up method to a closed-loop synchronous operation motor control algorithm for a synchronous motor having a permanent magnet rotor and stator windings. The method comprises initiating the closed-loop start-up method by energizing the stator windings to drive the permanent magnet rotor using motor control signals based on a detected, estimated, or randomly selected initial standstill angle of the permanent magnet rotor. The method includes estimating rate of change values of rotor flux linkage magnitude with respect to a selected vector axis of a two-dimensional rotating orthogonal reference frame of the synchronous motor based on back-electromotive force (emf) induced in the stator windings by rotation of the permanent magnet rotor; and switching-over control of the synchronous motor to the closed-loop synchronous operation motor control algorithm upon determining that one of the rate of change values of the rotor flux linkage magnitude has met a predetermined condition.

A method with which stalling of a rotor of a sensor-free motor can be detected is described below. According to one exemplary embodiment, the method comprises operating an electric motor, wherein a rotation speed of the electric motor is controlled by field-oriented control, and wherein an estimate is calculated, wherein the estimate represents magnetic flux in the electric motor. The method further comprises calculating a value which represents the change in the magnitude of the estimate for the magnetic flux and comparing the calculated value with a threshold value in order to detect whether the calculated value lies below the threshold value. An error is flagged if it is detected that the calculated value lies below the threshold value for a specific time.