scholarly journals A New Optimal DTC Switching Strategy for Open-End Windings Induction Machine using Dual Inverter

2021 ◽  
Vol 12 (3) ◽  
pp. 1405
Author(s):  
Nabilah Aisyah ◽  
Maaspaliza Azri ◽  
Auzani Jidin ◽  
M. Z. Aihsan ◽  
MHN Talib
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Dynamic Condition ◽  
Dynamic Control ◽  
Direct Torque Control ◽  
Torque Control ◽  
Dynamic Responses ◽  
Voltage Source ◽  
Optimal Switching ◽  
Stator Flux

<span>Since the early 1980s, fast torque dynamic control has been a subject of research in AC drives. To achieve superior torque dynamic control, two major techniques are used, namely Field Oriented Control (FOC) and Direct Torque Control (DTC), spurred on by rapid advances in embedded computing systems. Both approaches employ the space vector modulation (SVM) technique to perform the voltage source inverter into over modulation region for producing the fastest torque dynamic response. However, the motor current tends to increase beyond its limit (which can damage the power switches) during the torque dynamic condition, due to inappropriate flux level (i.e. at rated stator flux). Moreover, the torque dynamic response will be slower, particularly at high speed operations since the increase of stator flux will produce negative torque slopes more often. The proposed research aims to formulate an optimal switching modulator and produce the fastest torque dynamic response. In formulating the optimal switching modulator, the effects of selecting different voltage vectors on torque dynamic responses will be investigated. With greater number of voltage vectors offered in dual inverters, the identification of the most optimal voltage vectors for producing the fastest torque dynamic responses will be carried out based on the investigation. The main benefit of the proposed strategy is that it provides superior fast torque dynamic response which is the main requirements for many AC drive applications, e.g. traction drives, electric transportations and vehicles.</span>

scholarly journals Direct torque control of IM using PID controller

2020 ◽  
Vol 10 (1) ◽  
pp. 617
Author(s):  
Ali Najim Abdullah ◽  
Mohammed Hasan Ali
Keyword(s):  
Pid Controller ◽  
High Performance ◽  
Dynamic Performance ◽  
Asynchronous Motor ◽  
Direct Torque Control ◽  
Torque Ripple ◽  
Torque Control ◽  
Voltage Source ◽  
Stator Flux ◽  
Flux Response

Direct torque control "DTC" technique is one of a high performance control system of an AC motor drive, which was proposed after the vector oriented control scheme during the resent 25 years. It has been developed rapidly for its concise system scheme, transient and dynamic performance. The DTC mechanism consists of voltage vector selection table, two hysteresis comparators and two estimators one for stator flux and another for electromagnetic torque. DTC is directly control torque and flux by using Voltage Source Inverter VSI, space vector and stator flux orientation and indirect speed regulated. A several control techniques can be used for improving the torque and flux performance. In this paper, the DTC with Proportional-Integral-Derivative (PID) controller used to improve the starting and dynamic performance of asynchronous motor AM, which gives good torque and flux response, best speed control and also minimize the unacceptable torque ripple. The mathematical model of DTC with PID controller of 3-phase induction motor IM are simulated under Matlab-Simulink. Therefore, the DTC based on PID controller has good performance of IM compared to classical DTC for starting, running state and also during change in load.

scholarly journals A Novel Switching Table for a Modified Three-Level Inverter-Fed DTC Drive with Torque and Flux Ripple Minimization

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4646
Author(s):  
Yashar Farajpour ◽  
Mohamad Alzayed ◽  
Hicham Chaoui ◽  
Sousso Kelouwani
Keyword(s):  
Control Strategy ◽  
High Speed ◽  
Direct Torque Control ◽  
Harmonic Distortion ◽  
Neutral Point ◽  
Torque Control ◽  
Performance Indexes ◽  
Proposed Model ◽  
Comparative Results ◽  
Stator Flux

The use of a direct torque control (DTC) drive is a well-known control strategy that is applied frequently to induction motors. Although torque and stator flux ripples are major disadvantages of this approach, using a higher-level inverter helps to overcome these issues. In this paper, we propose a novel switching table with a modified control strategy for a three-level inverter to achieve ripple minimization, as well as smooth switching and neutral point balance; the latter features are generally ignored in many works. The proposed model is compared with a conventional DTC and an improved three-level inverter-fed voltage vector synthesis model in the Matlab/Simulink® environment with low, normal, and high-speed operation under load torque disturbances. The performance indexes and the comparative results confirm the effectiveness of the proposed model in reducing the torque and stator flux ripples by up to 70% and 78%, respectively, generating a lower total harmonic distortion (THD%) in all scenarios, in addition to maintaining the neutral point balance and preventing voltage jumps across the switches of the inverter.

scholarly journals Direct Torque Control of Two Induction Motors Using the Nine-Switch Inverter

2018 ◽  
Vol 9 (4) ◽  
pp. 1552
Author(s):  
Draoui Abdelghani ◽  
Allaoua Boumediène
Keyword(s):  
Induction Motors ◽  
Direct Torque Control ◽  
Industrial Applications ◽  
Torque Control ◽  
Voltage Source ◽  
Voltage Source Inverter ◽  
Voltage Source Inverters ◽  
Semiconductor Switches ◽  
Control Scheme ◽  
Stator Flux

<span lang="EN-US">The Nine-Switch Inverter</span><span lang="EN-US">(NSI) is a recently developed dual output converter. It can be used to drive two three-phase loads independently. As a substitute to two separate conventional voltage source inverters, the NSI has been, already, proposed in various industrial applications to reduce the number</span><span lang="EN-US">of semiconductor switches and its associated energy losses and drive circuitry. On the other hand, the Direct Torque Control</span><span lang="EN-US">(DTC) is a robust control scheme of AC motors, which consist of selecting proper state vectors of a conventional voltage source inverter. The NSI, having a different working principle from the conventional voltage source inverter and taking into account the varying influence of active space vectors on motor’s torque and stator flux, a Direct Torque Control is suggested in this paper to, efficiently, drive two induction motors independently, while minimizing the torque and stator flux ripples of both motors. Simulations results confirm the effectiveness of the proposed algorithm. In addition, application of this newly proposed control scheme in operation of an Electric Vehicule</span><span lang="EN-US">(EV) is demonstrated.</span>

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.

Sensorless Grey Prediction Fuzzy Direct Torque Control for High-Speed Permanent Magnet Synchronous Motor

2012 ◽  
Vol 220-223 ◽  
pp. 1040-1043
Author(s):  
Hong Cui ◽  
You Qing Gao
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
High Performance ◽  
Permanent Magnet Synchronous Motor ◽  
Direct Torque Control ◽  
Synchronous Motor ◽  
Torque Control ◽  
Adjustment Process ◽  
Grey Prediction ◽  
The Stability

High-speed permanent magnet synchronous motor (PMSM) is more and more widely applied in high precision processing and high-performance machines. It is very important to research practical control strategy for the stability operation of the high-speed PMSM. The strategy of sensorless grey prediction fuzzy direct torque control (DTC) is proposed which is suitable for high-speed PMSM control system. The method of prediction fuzzy control based on DTC is used to gain the flux, torque and flux oriented angle through the prediction model of the motor parameters. The best control scheme is gained by fuzzy reasoning to overcome the lag on the system making the adjustment process stable and realizing accurate predictive control. Thereby, the dynamic response of the system, anti-disturbance capability and control accuracy can be improved.

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