A motor drive system according to an embodiment includes an inverter and a control device. The inverter causes a current to flow through a winding of an induction motor. The control device drives the induction motor by controlling the inverter through vector control. The control device includes a plurality of calculation criteria for a stator magnetic flux estimated value of the induction motor and includes an appropriate magnetic flux command generation unit that selects a calculation criterion for the stator magnetic flux estimated value that further increases a loss of the induction motor from among the plurality of calculation criteria on the basis of at least a rotation speed of the induction motor in the case of braking the induction motor.

A method for controlling an asynchronous electrical motor, implemented in a processing unit associated with a power converter connected to the electrical motor, the method including an identification phase, which includes generating a speed trajectory in input of a control law of the motor in order to make the speed reference take several determined successive values, for each value taken by the speed reference, determining the voltage at the terminals of the electrical motor, for each value taken by the speed reference, determining and storing the flux value for which the voltage at the terminals of the electrical motor is equal to a determined threshold value.

A system for estimating flux linkage in an electric motor includes a flux estimation module that generates estimated flux linkages based on a back electromagnetic force and estimated velocity of the electric motor, the flux linkages having an alpha flux linkage component and a beta flux linkage component, and a velocity estimation module that generates an estimated motor velocity based on the back electromagnetic force and the estimated flux linkages.

The present invention relates to a method of determining the magnetic flux φ of an electric machine, based on measurements (MES) of currents and voltages in the phases of the electric machine, on a dynamic model (MOD) of the magnetic flux and on an adaptive Kalman filter (KAL).

A control system for a switched reluctance (SR) machine having a rotor and a stator is provided. The control system may include a converter circuit in electrical communication between the stator and a common bus, and a controller configured to monitor a bus voltage of the converter circuit and a phase current of the SR machine. The controller may be configured to determine a phase voltage based on one or more of main pulses and any diagnostic pulses, determine an estimated flux based on the phase voltage and an associated mutual voltage, determine a rotor position based at least partially on the estimated flux, and control the SR machine based on the rotor position and a desired torque.

An apparatus for controlling an induction motor is provided, the apparatus generates generating a d-axis current command and a q-axis current command of a torque command, estimating speed of a rotor of the motor, and correcting the d-axis and q-axis current commands by using the estimated speed, to enhances the rotor speed and position estimation performance by increasing the slip frequency.

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.

A power conversion device includes processing circuitry that estimates a magnet magnetic flux of an electric motor based on a d-axis magnetic flux generated in the electric motor, a d-axis inductance of the electric motor, and a d-axis current flowing in the electric motor, estimates a q-axis inductance of the electric motor based on a q-axis magnetic flux generated in the electric motor and a q-axis current flowing in the electric motor, estimates a drive force of the electric motor based on the magnet magnetic flux and the q-axis inductance, and corrects a current command such that the drive force follows a drive force command.

An electric motor is controlled using a feedback signal that includes an error between the measured current and the estimated current determined using the measured current, the measured voltage, and a model of the motor. A feedback gain is determined as an error function of a feedback signal and a speed of the motor is estimated using a product of the feedback gain and the feedback signal. The voltage of the motor is determined using a difference between the estimated speed of the motor and a reference speed of the motor and the motor us controlled using the determined voltage.

A motor drive system and method for determining an optimized efficiency of the motor drive system are provided. The motor drive system includes a system controller, a motor drive having includes an inverter configured to generate the AC power upon one or more motor leads, and an electric motor, which is to convert the AC power from the motor leads to rotational energy. A dynamometer may include a load coupled to the shaft and sensors to measure to measure operating characteristics such as torque and speed of the electric motor. The system controller is configured to generate a lookup table, with an entry describing an output current command for operating the inverter and the motor at a maximum system efficiency for a given combination rotational speed and output torque. Motor temperature may also be measured and used as an additional index into the lookup table.