ADAPATIVE ESTIMATE METHOD OF STATOR RESISTANCE IN STATOR FLUX ORIENTED DIRECT TORQUE CONTROL SYSTEM FOR INDUCTION MOTOR

2006 ◽  
Vol 42 (06) ◽  
pp. 24 ◽  
Author(s):  
Qinghui WU
Keyword(s):  
Control System ◽  
Induction Motor ◽  
Direct Torque Control ◽  
Torque Control ◽  
Estimate Method ◽  
Stator Flux ◽  
Stator Resistance ◽  
Stator Flux Oriented

scholarly journals Low-Speed Performance Improvement of Direct Torque Control for Induction Motor Drives Fed by Three-Level NPC Inverter

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 77 ◽  
Author(s):  
Samer Hakami ◽  
Ibrahim Mohd Alsofyani ◽  
Kyo-Beum Lee
Keyword(s):  
Induction Motor ◽  
Direct Torque Control ◽  
Basic Structure ◽  
Motor Drives ◽  
Torque Control ◽  
Low Speed ◽  
Speed Performance ◽  
Sinusoidal Current ◽  
Stator Flux ◽  
Stator Resistance

Classical direct torque control (DTC) is considered one of the simplest and fastest control algorithms in motor drives. However, it produces high torque and flux ripples due to the implementation of the three-level hysteresis torque regulator (HTR). Although, increasing the level of HTR and utilizing multilevel inverters has a great contribution in torque and flux ripples reduction, stator flux magnitude of induction motor (IM) droops at every switching sector transition, particularly at low-speed operation. This problem occurs due to the utilization of a zero voltage vector, where the domination of stator resistance is very high. A simple flux regulation strategy (SFRS) is applied for low-speed operation for DTC of IM. The proposed DTC-SFRS modifies the output status of the five-level HTR depending on the flux error, torque error, and stator flux position. This method regulates the stator flux for both forward and reverse rotational directions of IM with retaining the basic structure of classical DTC. By using the proposed algorithm, the stator flux is regulated, hence pure sinusoidal current waveform is achieved, which results in lower total harmonics distortion (THD). The effectiveness of the proposed DTC-SFRS is verified through simulation and experimental results.

scholarly journals RESEARCH OF THE DIRECT TORQUE CONTROL SYSTEM BY INDUCTION MOTOR

2018 ◽  
Vol 2 (48) ◽  
pp. 3-8
Author(s):  
Ahmed Ibrahim Jaber Alzubaydy ◽  
V. P. Dorohobid ◽  
Mohammed Saady Hasan ◽  
M. K. Borozdin
Keyword(s):  
Control System ◽  
Induction Motor ◽  
Mathematical Description ◽  
Direct Torque Control ◽  
Torque Control ◽  
Transient Processes ◽  
Flux Coupling ◽  
Matlab Program ◽  
Stator Flux ◽  
The Moment

The article presents a mathematical description of an induction motor with further modeling in the MATLAB program. In the model, the method of direct torque control (DTC) is implemented. The basic idea of control is that at each step of the calculation the optimum state of the inverter voltage is determined, which causes a change in both the moment and the stator flux coupling in the necessary direction. The obtained transient processes.

scholarly journals Performance Improvement of Servo Control System Driven by Novel PMSM-DTC Based On Fixed Sector Division Criterion

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2154 ◽  
Author(s):  
Dazhi Wang ◽  
Tianqing Yuan ◽  
Xingyu Wang ◽  
Xinghua Wang ◽  
Yongliang Ni
Keyword(s):  
Control System ◽  
Performance Improvement ◽  
Error Compensation ◽  
Permanent Magnet Synchronous Motor ◽  
Direct Torque Control ◽  
Torque Control ◽  
Servo Control ◽  
Flux Linkage ◽  
Servo Control System ◽  
Stator Flux

In order to improve the performance of the servo control system driven by a permanent magnet synchronous motor (PMSM) under novel direct torque control (NDTC), which, utilizing composite active vectors, fixed sector division criterion, is proposed in this paper. The precondition of the accurate compensations of torque and flux errors is that the sector where the stator flux linkage is located can be determined accurately. Consequently, the adaptive sector division criterion is adopted in NDTC. However, the computation burden is inevitably increased with the using of the adaptive part. On the other hand, the main errors can be compensated through SV-DTC (DTC-utilizing single active vector), while another active vector applied in NDTC can only supply the auxiliary error compensation. The relationships of the two active vectors’ characteristics in NDTC are analyzed in this paper based on the active factor. Furthermore, the fixed sector division criterion is proposed for NDTC (FS-NDTC), which can classify the complexity of the control system. Additionally, the switching table for the selections of the two active vectors is designed. The effectiveness of the proposed FS-NDTC is verified through the experimental results on a 100-W PMSM drive system.

Study on speed sensorless system of permanent magnet synchronous motor based on improved direct torque control

2021 ◽  
pp. 014233122110629
Author(s):  
Xiaoxin Hou ◽  
Mingqian Wang ◽  
Guodong You ◽  
Jinming Pan ◽  
Xiating Xu ◽  
...  
Keyword(s):  
Control System ◽  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Direct Torque Control ◽  
Torque Ripple ◽  
Synchronous Motor ◽  
Torque Control ◽  
Switching Frequency ◽  
Speed Sensorless ◽  
Stator Resistance

The traditional direct torque control system of permanent magnet synchronous motor has many problems, such as large torque ripple and variable switching frequency. In order to improve the dynamic and static performance of the control system, a new torque control idea and speed sensorless control scheme are proposed in this paper. First, by deriving the equation of torque change rate, an improved torque controller is designed to replace the torque hysteresis controller of the traditional direct torque control. The improved direct torque control strategy can significantly reduce the torque ripple and keep the switching frequency constant. Then, based on the improved direct torque control and considering the sensitivity of the stator resistance to temperature change, a speed estimator based on the model reference adaptive method is designed. This method realizes the stator resistance on-line identification and further improves the control precision of the system. The performance of the traditional direct torque control and the improved direct torque control are compared by simulation and experiment under different operating conditions. The simulation and experimental results are presented to support the validity and effectiveness of the proposed method.

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