Techniques and apparatus for determining the temperature of a permanent magnet on a rotor of an electrical motor. An example techniques involves determining a first set of parameters for controlling the electrical motor. A temperature of the rotor during a runtime of the electrical motor is determined, based at least in part on the first set of parameters and a first back-electromotive force (back-emf) associated with the electrical motor. A first estimate of a magnetic flux of the permanent magnet is determined based on the temperature of the rotor. An operation of the electrical motor is controlled based at least in part on the first estimate of the magnetic flux of the permanent magnet.

Techniques and apparatus for determining the temperature of a permanent magnet on a rotor of an electrical motor. An example techniques involves determining a first set of parameters for controlling the electrical motor. A temperature of the rotor during a runtime of the electrical motor is determined, based at least in part on the first set of parameters and a first back-electromotive force (back-emf) associated with the electrical motor. A first estimate of a magnetic flux of the permanent magnet is determined based on the temperature of the rotor. An operation of the electrical motor is controlled based at least in part on the first estimate of the magnetic flux of the permanent magnet.

A method for determining a motor angle, may include deriving a sensor weight and a sensorless weight via a cross product of an actual current vector and a model-based sensored current vector and a cross product of the actual current vector and a model-based sensorless current vector; and determining a final motor angle by applying the sensor weight and the sensorless weight to each of a sensored angle and a sensorless angle.

A method for determining a motor angle, may include deriving a sensor weight and a sensorless weight via a cross product of an actual current vector and a model-based sensored current vector and a cross product of the actual current vector and a model-based sensorless current vector; and determining a final motor angle by applying the sensor weight and the sensorless weight to each of a sensored angle and a sensorless angle.

A motor control device of an embodiment includes a power supply unit that supplies AC power to a motor; a current detection unit that detects a current flowing through a winding of the motor; a speed and electric angle estimation unit that estimates a rotation speed and an electric angle of the motor based on a voltage outputted by the power supply unit and the current; a coordinate conversion unit that obtains an excitation current and a torque current based on the current and the electric angle; a torque current command determination unit that substitutes a predicted torque calculated based on a mechanical motion equation into a torque component current command value calculated based on a torque expression of a vector control coordinate, to generate a torque component current command value for bringing a difference between an inputted speed command and an estimated speed closer to zero; and a model prediction control unit that applies, to a plurality of predicted currents including a current change ratio determined depending on each of a plurality of switching patterns based on a space voltage vector that are able to be outputted by the power supply unit, an evaluation function to evaluate a size of a difference from a predicted current corresponding to each of the torque component current command value and an excitation component current command value inputted from outside, and that selects and outputs a switching pattern.

A motor control device of an embodiment includes a power supply unit that supplies AC power to a motor; a current detection unit that detects a current flowing through a winding of the motor; a speed and electric angle estimation unit that estimates a rotation speed and an electric angle of the motor based on a voltage outputted by the power supply unit and the current; a coordinate conversion unit that obtains an excitation current and a torque current based on the current and the electric angle; a torque current command determination unit that substitutes a predicted torque calculated based on a mechanical motion equation into a torque component current command value calculated based on a torque expression of a vector control coordinate, to generate a torque component current command value for bringing a difference between an inputted speed command and an estimated speed closer to zero; and a model prediction control unit that applies, to a plurality of predicted currents including a current change ratio determined depending on each of a plurality of switching patterns based on a space voltage vector that are able to be outputted by the power supply unit, an evaluation function to evaluate a size of a difference from a predicted current corresponding to each of the torque component current command value and an excitation component current command value inputted from outside, and that selects and outputs a switching pattern.

A method for controlling a brushless and sensorless, direct current electric motor (3) for motor vehicle equipment, wherein the electric motor (3) comprises a rotor and phases (A, B, C) powered by a pulse width modulation applied to a power inverter (1) of the electric motor (3), and wherein, beyond a minimum threshold (S.sub.min) of the rotation speed of the rotor, the position of the rotor is determined from a measurement of electromotive forces at the phases (A, B, C) of the electric motor (3), said control method is characterised in that, in the event of a command (104) to stop the electric motor (3), the speed of rotation of the rotor is reduced (105) from a nominal speed to a predetermined rotation speed (V1) within a range between the minimum threshold (S.sub.min) and 10% above said minimum threshold (S.sub.min) by modifying the pulse width modulation, then the electric motor (3) is stopped (106) in a predetermined position by short-circuiting the branches (A, B, C) of the inverter (1) when the predetermined position is reached.

A method for controlling a brushless and sensorless, direct current electric motor (3) for motor vehicle equipment, wherein the electric motor (3) comprises a rotor and phases (A, B, C) powered by a pulse width modulation applied to a power inverter (1) of the electric motor (3), and wherein, beyond a minimum threshold (S.sub.min) of the rotation speed of the rotor, the position of the rotor is determined from a measurement of electromotive forces at the phases (A, B, C) of the electric motor (3), said control method is characterised in that, in the event of a command (104) to stop the electric motor (3), the speed of rotation of the rotor is reduced (105) from a nominal speed to a predetermined rotation speed (V1) within a range between the minimum threshold (S.sub.min) and 10% above said minimum threshold (S.sub.min) by modifying the pulse width modulation, then the electric motor (3) is stopped (106) in a predetermined position by short-circuiting the branches (A, B, C) of the inverter (1) when the predetermined position is reached.

The vibration and noise generated in a permanent magnet synchronous motor are effectively suppressed. A motor control device 1 comprises: a triangular wave generation unit 17 which generates a triangular wave signal Tr that is a carrier wave, a carrier frequency adjustment unit 16 which adjusts a carrier frequency fc that represents a frequency of the triangular wave signal Tr, and a gate signal generation unit 18 which performs pulse-width modulation on three-phase voltage commands Vu*, Vv*, Vw* according to a torque command T* using the triangular wave signal Tr, thereby generating a gate signal for controlling an operation of an inverter. The carrier frequency adjustment unit 16 adjusts the carrier frequency fc so as to change a voltage phase error Δθv representing a phase difference of the three-phase voltage commands Vu*, Vv*, Vw* and the triangular wave signal Tr based on the torque command T*, and a rotation speed ωr of a motor.

The vibration and noise generated in a permanent magnet synchronous motor are effectively suppressed. A motor control device 1 comprises: a triangular wave generation unit 17 which generates a triangular wave signal Tr that is a carrier wave, a carrier frequency adjustment unit 16 which adjusts a carrier frequency fc that represents a frequency of the triangular wave signal Tr, and a gate signal generation unit 18 which performs pulse-width modulation on three-phase voltage commands Vu*, Vv*, Vw* according to a torque command T* using the triangular wave signal Tr, thereby generating a gate signal for controlling an operation of an inverter. The carrier frequency adjustment unit 16 adjusts the carrier frequency fc so as to change a voltage phase error Δθv representing a phase difference of the three-phase voltage commands Vu*, Vv*, Vw* and the triangular wave signal Tr based on the torque command T*, and a rotation speed ωr of a motor.