scholarly journals An Efficient of Direct Torque Control of Indirect Three Level Matrix Converter Fed Dual Stator Induction Motor Based on Synergetic Controller

2020 ◽  
Vol 53 (5) ◽  
pp. 617-627
Author(s):  
Yahia Moati ◽  
Katia Kouzi

As know, Direct Torque Control (DTC) suffers from the high ripples of the torque and flux, caused by the variable switching frequency. Torque ripple in DTC drives can be reduced if an Indirect Three-Level Matrix Converter (ITLMC) is employed instead of a conventional Two-Level Indirect Matrix Converter. Nevertheless, this problem can be still large if low switching frequencies are used. In order to overcome this problem, a Constant Switching Frequency controller (CSFC) is proposed to replace the five-level hysteresis torque comparator for reducing the ripples and improving the flux regulation in low and zero speed operation. Furthermore, the control scheme performance is enhanced by inserting a robust Synergetic Controller (SC) in the outer loop for speed regulation. Simulation results with a comparative analysis have indicated the special merit of the proposed scheme, which makes it competitive with the existing control strategies.

2019 ◽  
Vol 11 (9) ◽  
pp. 2604 ◽  
Author(s):  
Arzhang Yousefi-Talouki ◽  
Shaghayegh Zalzar ◽  
Edris Pouresmaeil

In this paper, a direct power control (DPC) technique is proposed for matrix converter-fed grid-connected doubly fed induction generators (DFIGs). In contrast to what has been investigated in the past for direct torque control (DTC) or DPC of matrix converter-fed DFIGs, the active and reactive powers are regulated in a fixed switching frequency using indirect space vector modulation (ISVM) technique. Hence, designing input filters for matrix converters (MCs) becomes convenient. In addition, the reactive component of input side of MC is controlled which leads to reduction of distortion in grid current waveform. Also, an extensive discussion is addressed for nonlinear voltage errors of MC that may cause inaccurate power control. Simulation results done in MATLAB/Simulink show the effectiveness of the proposed method.


2020 ◽  
Author(s):  
Adhavan Balashanmugham ◽  
Maheswaran Mockaisamy ◽  
Sathiyanathan Murugesan

The asynchronous or Induction Motor (IM) is one of the most widely used electrical machines in the world, due to the three following advantages namely 1.Their construction is simple and rugged 2.The absence of slip rings, commutators and brushes make it cheaper, and 3.It is also maintenance free compared to DC motors and Synchronous motor due to wear and tear of brushes, slip rings and commutators respectively. The Section 1 deals with the introduction of induction motor and Direct Torque Control scheme. Section 2 briefly discusses the types of Induction motor. Section 3 tells about the control strategies of Induction motor respectively scalar control and vector control, and also briefly explains about Direct Torque Control (DTC) method. The Section 4 discuss about the Types of Control Strategies for Torque ripple Reductions in DTC as well as the two proposed schemes namely 1.Fuzzy Logic Controller (FLC) for DTC-SVM and 2.Artificial Neural Network (ANN) controller for DTC-SVM respectively for IM and its results, The two proposed schemes uses Hybrid Asymmetric Space Vector Pulse Width Modulation (HASVPWM) for switching the inverter. The Section 5 revels about the modern advanced techniques such as ANN and FLC based DTC.


Author(s):  
Xiaoxin Hou ◽  
Mingqian Wang ◽  
Guodong You ◽  
Jinming Pan ◽  
Xiating Xu ◽  
...  

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.


2011 ◽  
Vol 291-294 ◽  
pp. 2871-2874
Author(s):  
Li Hua Zou

In direct torque control system for induction motor, the system has big torque ripple and strong noise caused by torque ripple. In indirect stator-quantities control, a slip frequency controller, based on power frequency exponent integration reaching law sliding model, is adopted by using practical measure velocity and calculation torque of motor flux model. The slip frequency error is fast convergent and stable in the nearby zero value, the method reduces torque ripple and improve dynamic and stable performance. The stability analysis of the scheme is given by using Lyapunov method. The simulation results verify the effectiveness and correctness of the method.


Author(s):  
Huzainirah Ismail ◽  
Fazlli Patkar ◽  
Auzani Jidin ◽  
Aiman Zakwan Jidin ◽  
Noor Azida Noor Azlan ◽  
...  

<p>Direct Torque Control (DTC) is widely applied for ac motor drives as it offers high performance torque control with a simple control strategy. However, conventional DTC poses some disadvantages especially in term of variable switching frequency and large torque ripple due to the utilization of torque hysteresis controller. Other than that, performance of conventional DTC fed by two-level inverter is also restricted by the limited numbers of voltage vectors which lead to inappropriate selection of voltage vectors for different speed operations. This research aims to propose a Constant Switching Frequency (CSF) torque controller for DTC of induction motor (IM) fed by three-level Neutral-Point Clamped (NPC) inverter. The proposed torque controller utilizes PI controller which apply different gain for different speed operation. Besides, the utilization of NPC inverter provides greater number of voltage vectors which allow appropriate selection of voltage vectors for different operating condition. Using the proposed method, the improvement of DTC drives in term of producing a constant switching operation and minimizing torque ripple are achieved and validated via experimental results.</p>


Author(s):  
Amirah J. Mohammed ◽  
◽  
Raaed F. Hassan

The work presented in this paper aims to compare the effectiveness of different control strategies to improve the performance of the three-phase Induction Motor (IM). The Conventional Direct Torque Control (CDTC) was employed as the first strategy for driving the IM. This control strategy causes high ripples in the IM's torque and speed due to the hysteresis comparators and a variable switching frequency due to the look-up table. A modified DTC strategy based on Space Vector Modulation (DTC-SVM) was chosen as a second strategy to enhance the performance of the IM using the two-level inverter. This method, which leads to the reduction of the torque and speed ripples and achieves constant switching frequency. As the multi-level inverter becomes most popular than the two-level inverter, the third strategy is devoted to adopting the three-level flying capacitor inverter (TLFCMLI) -based DTC-SVM. The third strategy uses the method of mapping the multi-level space vector based on basic two-level SVM. Matlab/Simulink software package is utilized to implement the suggested controllers. Simulation results show that the DTC-SVM based on TLFCMLI significantly enhances the IM's performance compared with the other two strategies from the voltage and current profiles, torque, and speed points of view.


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