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.

In a method for determining the rotor position of a three-phase machine without using a rotary encoder, and a device for controlling a three-phase motor without using a rotary encoder, the three-phase machine is fed by a converter that can be operated by pulse-width modulation, and the converter has model variables for the rotor angle and the current indicator of the three-phase machine, and the converter has device(s) by using which, in control operation, at least two values are measured which represent a measure of the local inductances of the machine which represent a measure of the local inductances of the machine, the error of the model rotor angle is determined in that, depending on the model rotor angle and the model current indicator, at least two weighting factors are determined, and in that a weighted sum is formed from the at least two measured values and the at least two weighting factors, and in that a further offset value is subtracted from the sum, which is likewise determined on the basis of the model rotor angle and the model current indicator.

A rotary machine control device for controlling a rotary machine whose inductance has an inductance variable component that changes with a rotor position includes a current detector detecting rotary machine current flowing through the rotary machine; and a speed estimator computing estimated rotational speed that is an estimated value of rotational speed of a rotor, based on motional electromotive force that is induced voltage generated due to change in the inductance with a rotor position. The rotary machine control device includes a position computing unit computing an estimated position that is an estimated value of the rotor position, using the estimated rotational speed; and a controller outputting a rotary machine voltage instruction to drive the rotary machine, based on the rotary machine current and the estimated position. The rotary machine control device includes a voltage applicator applying voltage to the rotary machine based on the rotary machine voltage instruction.

A method for reducing a total operational load of a method of a model predictive control-by conducting simplifications based on specific observations, in order to drive alternating current motors by using the method of the MPC with a two-level voltage source inverter. The method includes the steps of determining at which one of the predefined sectors a resultant of stator currents is present, determining a motor mode, reducing seven estimation vectors to four estimation vectors and calculating a cost function or reducing seven estimation vectors to five estimation vectors and calculating the cost function.

A method suitable for characterizing a motor, for instance a permanent magnet synchronous motor, includes obtaining a plurality of winding flux linkage values or terminal voltages of the motor, each corresponding to a different combination of phase current magnitude and phase advance. The resultant flux-linkage values or terminal voltages are transformed into the rotor dq reference frame. The flux linkage model is fitted to the one or more dq-axis flux-linkage values or terminal voltages and their linked phase current magnitude and phase advance using a process of parametric optimisation.

A method for noise reduction of a three-phase-driven electrical machine includes recording an angular state of a rotor of the electrical machine, calculating a reference frequency on the basis of the recorded angular state, forming a sine and cosine value of the calculated reference frequency, and filtering the sine and cosine value. The method may also include recording a sound-related feedback variable, forming a weighting vector, forming a superposition signal, and applying the superposition signal to a manipulated variable of the electrical machine.

A method of calibrating a motor assembly includes selecting an electric motor and a motor controller for the motor assembly, obtaining at least one electric motor parameter of the electric motor, determining a correction factor for the electric motor based upon the at least one electric motor parameter, and programming the motor controller with the correction factor.

The present disclosure provides a predictive control method of current increment for a permanent magnet synchronous motor includes: substituting a mathematical expression of a stator voltage during one control period into a continuous time domain current model to obtain a discrete current prediction model and a predicted current at the next time point; obtaining a predicted current increment from a current increment prediction model by subtracting a predictive current at a present time point from a predictive current at a next time point; establishing a cost function according to a preset reference current increment and the predicted current increment; obtaining an optimal voltage increment by minimizing the cost function; superposing the optimal voltage increment on a stator voltage of a present control period to obtain an optimal stator voltage of a next control period for controlling control the permanent magnet synchronous motor.

A method of speed control based on a self-learning model of load torque and a moment inertia is applied to a controller of controlling a motor. The method includes steps of: establishing a relationship between the load torque and the moment inertia by a self-learning manner, correspondingly acquiring a value of the moment inertia according to a value of the load torque, and adjusting parameters of the controller to control rotation of the motor according to the value of the moment inertia.

A unified open-circuit fault-tolerant control method for a vector control (VC) drive system and a direct torque control (DTC) drive system of a five-phase permanent magnet fault-tolerant motor are provided. The control method adopts a unified open-circuit fault-tolerant control strategy. The unified open-circuit fault-tolerant control strategy includes: obtaining a predetermined torque, obtaining predetermined direct-axis and quadrature-axis voltages, analyzing a fault-tolerant mechanism to obtain fault-tolerant currents, obtaining winding phase voltages in a fault mode based on the fault-tolerant mechanism, and obtaining fault-tolerant voltages based on a back-electromagnetic force (EMF). The unified open-circuit fault-tolerant control strategy suitable for the VC drive system and the DTC drive system is proposed based on chaotic pulse width modulation (CPWM). The control method essentially reveals the fault-tolerant mechanism, and solves the problem of variable and complicated fault-tolerant control schemes corresponding to various basic control algorithms.