Direct Torque Control for a Bearingless Induction Motor Based on Model prediction

Purpose The purpose of this paper is to address the large stator flux linkage ripple and electromagnetic torque ripple caused by the hysteresis comparator in traditional direct torque control for a bearingless induction motor (BIM). Design/methodology/approach Model predictive direct torque control (MPDTC) strategy is adopted. On the basis of the mathematical model of BIM, the stator current and stator flux observational values are obtained, and the electromagnetic torque and stator flux at the next moment are predicted. Then, based on the relationship between the stator flux and the electromagnetic torque, the predicted stator flux can be transformed into an equivalent flux linkage vector, which eliminates the weighting coefficients problem among multiple variables in traditional objective functions. The objective function and torque PI controller will output the optimal stator flux linkage and the increments of the torque phase angle. Through the phase angle increments, the space voltage vector can be obtained by the reference flux linkage controller instead of the stator flux linkage and the torque hysteresis controller. Findings The proposed MPDTC method can effectively improve the stator flux linkage and the torque ripple. It can implement the stable suspension of the rotor and improve the dynamic performance and steady-state accuracy of the BIM system. Originality/value A MPDTC strategy is proposed to reduce the ripple of stator flux and electromagnetic torque. The phase angle increment angle of stator flux linkage and electromagnetic torque is optimized by model prediction, and the optimal space voltage vector is obtained by designing the reference flux controller.

Flux-weakening control methods for hybrid excitation synchronous motor

The hybrid excitation synchronous motor (HESM), which aim at combining the advantages of permanent magnet motor and wound excitation motor, have the characteristics of low-speed high-torque hill climbing and wide speed range. Firstly, a new kind of HESM is presented in the paper, and its structure and mathematical model are illustrated. Then, based on a space voltage vector control, a novel flux-weakening method for speed adjustment in the high speed region is presented. The unique feature of the proposed control method is that the HESM driving system keeps the q-axis back-EMF components invariable during the flux-weakening operation process. Moreover, a copper loss minimization algorithm is adopted to reduce the copper loss of the HESM in the high speed region. Lastly, the proposed method is validated by the simulation and the experimental results.

Simulation of DC Regulated Power Supply by SVPWM Control

To make the voltage of and the power factor of AC side adjustable, according to the working principle of the three-phase voltage source PWM rectifier,establish the mathematical model of DC regulated power supply, introduce the space voltage vector modulation technology, and build its circuit model based on SVPWM control on the Matlab/Simulink software platform, The simulation results show that this control strategy is feasible.

Research on Drive and Control System of Bearingless Brushless DC Motor for Satellite Flywheel

Compared with the complex structure and unsatisfactory performance of traditional flywheel drive system, the proposed strategy adopts bearingless brushless DC motor as the drive actuator of flywheel. The direct torque control which combines the space voltage vector pulse width modulation is presented to control the system. Moreover, a simulation system is built with Matlab/Simulink toolbox. From the simulation results, the proposed control strategy is verified and the rotor can be stably suspended by suspension force along the central axis.

Research on the Method of Variable-Frequency Hysteresis SVPWM Current Control for Three-Phase PWM Rectifier

Aiming at the shortcomings of the method of conventional hysteresis current control for three-phase PWM rectifier, this paper proposes a new method, which combines Variable-frequency hysteresis current control with Space Vector Pulse-width Modulation (SVPWM) strategy. With this method, the error current can be limited in a given hysteresis loop by switching the space voltage vector of the voltage source PWM rectifier (VSR) in real time. And it can get a faster response for the current, while the frequency of the switches can be reduced. So, this method can obtain a high quality for the current control of PWM rectifier.

Simulation Study of Permanent Magnet Synchronous Motors Energy Feedback Control System

Combined with the brake working principle of Permanent magnet synchronous motors, the three-phase PWM rectifier mathematical model and Simulink simulation model are set up. On this basis, according to the design requirements of energy feedback system, the voltage current double-loop control is applied in this system. The space voltage vector tracking is achieved by the use of space voltage vector PWM algorithm. The system modeling and simulation study is conducted in the MATLAB simulation environment, and the correctness of the proposed program is verified, which provides the corresponding theoretical basis for the future product design.

Research on Neutral-Point Balancing for Three-Level Space Voltage Vector Converter

A novel hybrid clamped dual-PWM three-level converter topology is proposed for induction motor drives in this paper. The switching states of hybrid clamp three-level converters increase to sixty-four from twenty-seven switching states of diode clamp three-level converters. In order to realize optimization of its redundant voltage space vectors by detecting voltage of clamp capacitor and difference of capacitor voltage in DC side, Generating an optimized switching pattern, The hybrid clamped three-level converter increases the voltage levels number, reducing the harmonics associated to the commutation frequency and limiting the dv/dt by all the switches . It can quickly balance the DC voltage, Realized system of 4-Quardant Running. the control circuit and main circuit was designed with DSP and CPLD, experimentation results proved it is very effective and practicability.