A speed estimating device for an AC motor includes: a model deviation computing unit computing a model deviation based on a voltage, a current, and an estimated angular velocity of the AC motor; a first angular velocity estimating unit computing a first estimated angular velocity based on the model deviation; a second angular velocity estimating unit computing a second estimated angular velocity differing from the first estimated angular velocity in frequency, based on the model deviation; a compensation phase computing unit computing a compensation phase based on a disturbance frequency; and an estimated angular velocity calculator computing an estimated angular velocity of the AC motor based on the first estimated angular velocity and the second estimated angular velocity. Either one of the first estimated angular velocity and the second estimated angular velocity is computed based on the compensation phase.

A motor temperature and torque estimation device comprises: a temperature sensor; a losses estimation circuitry to estimate an iron loss; a first temperature estimation circuitry to estimate a first magnet temperature from the estimated iron loss and a sensor's detected temperature; a second temperature estimation circuitry, to input into a magnet's magnetic flux calculator thereinside motor's modified inductance, to estimate a second magnet temperature from magnet's magnetic flux calculated through voltage equations; a magnet-temperature estimation circuitry to estimate a motor's magnet temperature from the first and second magnet temperatures; a magnet's magnetic estimation circuitry to estimate magnetic flux based on the calculated/modified one, the motor's estimated magnet temperature and temperature characteristics, and to output the estimated magnetic flux into the losses estimator; and a torque estimation circuitry to estimate torque based on the estimated magnetic flux and iron loss, wherein a motor's magnet temperature(s) and torque are estimated.

A motor controller configured to drive a permanent magnet synchronous motor (PMSM) with Field Oriented Control (FOC), includes a current controller configured to generate control signals for driving the PMSM. The current controller is configured to measure current information of the PMSM, including a direct-axis motor current and a quadrature-axis motor current. The current controller includes a direct-axis current regulator configured to receive a direct-axis reference current and the direct-axis motor current to generate a direct-axis error value based on a difference between the direct-axis reference current and the direct-axis motor current. The current controller includes a voltage regulator configured to regulate a DQ voltage vector comprising a direct-axis motor voltage and a quadrature-axis motor voltage, wherein the voltage regulator generates the direct-axis motor voltage based on the direct-axis error value and a voltage vector limiting function to drive the direct-axis motor current to zero.

Described is a method of controlling operation of a synchronous motor. The method comprises, during constant power/speed motor operation, determining a value of a stator voltage (v.sub.s.sup.2) for an orthogonal rotating reference frame of the motor. Comparing the value of the determined stator voltage (v.sub.s.sup.2) to a threshold voltage (v.sub.s.sup.2.sub._max 1), said threshold voltage (v.sub.s.sup.2.sub._max 1) having a value between that of a maximum stator voltage (v.sub.s.sup.2.sub._max 0) for a basic speed mode of operation of the motor and that of a maximum stator voltage (v.sub.s.sup.2.sub._max 2) of the motor closed loop controller. If the determined value of the stator voltage (v.sub.s.sup.2) is greater than or equal to the value of the threshold voltage (v.sub.s.sup.2.sub._max 1), then controlling operation of the motor in a flux weakening mode of operation until a value of a current component (i.sub.d−Δi.sub.d) in a d-axis reaches a maximum negative value (−i.sub.d max), or until the value of the stator voltage (v.sub.s.sup.2) is less than the value of the threshold voltage (v.sub.s.sup.2.sub._max 1).

A method of controlling a motor controlled by a motor controller that includes a complex vector flux regulator (CVλR). The method includes: receiving at a field weakening regulator of the motor controller a modulation index that is a scaled version of an available voltage available to be provided to the motor by a voltage source; comparing the modulation index to a feedback modulation index to produce an error scalar that has a magnitude in a flux domain; determining a final direction (α.sub.final) of the error scalar in the flux domain; and providing the CVλR with flux commands in the d and q domain based on the error scalar and the direction.

There is provided a synchronous machine control device capable of improving the performance of a motor without complicating a control system. The synchronous machine control device controls a power converter (2) that supplies electric power to a synchronous machine (1). The synchronous machine control device includes a first magnetic flux command computation unit (21) that computes a first magnetic flux command value (φd*, φq*) from a current command value (Id*, Iq*) of the synchronous machine (1), a magnetic flux estimation unit (23) that estimates a magnetic flux value (φdc, φqc) of the synchronous machine (1) from a current detection value (Idc, Iqc) of the synchronous machine (1), and a voltage computation unit (19) that creates a voltage command value (Vd*, Vq*) of the power converter such that the first magnetic flux command value (φd*, φq*) coincides with the magnetic flux value (φdc, φqc).

To provide a controller for AC rotary electric machine which can control considering the interlinkage fluxes of first-axis and second-axis which change mutually according to the currents of first-axis and second-axis, such as d-axis and q-axis. A controller for AC rotary electric machine calculates interlinkage flux model response values of first-axis and second-axis by performing a response delay processing of a model response to the interlinkage flux command values of first-axis and second-axis; and calculates voltage command values of first-axis and second-axis which make interlinkage fluxes of first-axis and second-axis change to the interlinkage flux model response values of first-axis and second-axis in a feedforward manner, based on the interlinkage flux model response values of first-axis and second-axis, and the electrical angle speed.

A rotary machine control device includes: a magnetization characteristics determiner that determines a magnet phase of a magnet flux based on an estimated magnetic flux and a detection current, and determines a qm-axis magnetic flux of the estimated magnetic flux, a qm-axis current of the detection current, and a harmonic component of a magnet phase using a dm-qm coordinate system with a dm axis representing the magnet phase and a qm axis representing a phase shifted by 90 degrees from the magnet phase; a ripple compensation determiner that determines a ripple compensation phase using a ripple compensation torque obtained based on the qm-axis current and the harmonic component; a command phase determiner that determines a command phase based on the ripple compensation phase and a torque command; and a command magnetic flux generator that generates a command magnetic flux based on a command amplitude and the command phase.

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.

Provided is a motor controller that can estimate the magnetic flux of a magnet without changing a current of an electric motor. A motor controller 1 includes a current detecting unit 15 that detects a current of an electric motor 5, a current stability determining unit 10 that determines whether or not a current detected by the current detecting unit 15 is stable, and a magnetic flux calculating unit (filters 8a to 8e, a current conversion unit 4b, a resistance calculating unit 9, a magnet magnetic flux estimating unit 11) that based on a determination made by the current stability determining unit 10 as to current stability, calculates the magnetic flux of a magnet of the electric motor 5, according to a voltage equation in a rotating coordinate system, to output the calculated magnet flux. The motor controller 1 further includes a control voltage output unit (a map 2, voltage instruction units 3a and 3b, a first three-phase conversion unit 4a) that outputs a control voltage to the electric motor 5, based on the magnetic flux of the magnet calculated by the magnetic flux calculating unit and on a torque instruction value.