Constant Frequency Torque Controller for DTC with Multilevel Inverter of Induction Machines

Author(s):  
Norjulia Mohamad Nordin ◽  
Naziha Ahmad Azli ◽  
Nik Rumzi Nik Idris ◽  
Nur Huda Ramlan ◽  
Tole Sutikno

Direct Torque Control using multilevel inverter (DTC-MLI) with hysteresis controller suffers from high torque and flux ripple and variable switching frequency. In this paper, a constant frequency torque controller is proposed to enhance the DTC-MLI performance. The operational concepts of the constant switching frequency torque controller of a DTC-MLI system followed by the simulation results and analysis are presented. The proposed system significantly improves the DTC drive in terms of dynamic performance, smaller torque and flux ripple, and retain a constant switching frequency.

2013 ◽  
Vol 646 ◽  
pp. 134-138
Author(s):  
Fethia Hamidia ◽  
Abdelakader Larabi ◽  
Mohamed Seghir Boucherit

The conventional Direct Torque Control approach has some drawbacks such as high torque ripple and switching frequency, which is varying with speed, load torque and the selected hysteresis bands, this paper discuss the application of neural network and fuzzy logic on DTC of Doubly fed induction motor DFIM, the proposed techniques having the advantages of low torque and flux ripples. Simulation results emphasize the good performance of the fuzzy and neural techniques.


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>


2012 ◽  
Vol 614-615 ◽  
pp. 1570-1573
Author(s):  
Ying Pei Liu ◽  
Ran Li ◽  
Zhi Chao Zhang

In order to reduce the ripples of flux linkage and torque for direct torque control (DTC) and ensure constant inverter switching frequency, permanent magnet synchronous motor (PMSM) DTC based on space vector modulation (SVM) and extended Kalman filter (EKF) is researched in the paper. Simulation results have shown that the inherent advantages of fast dynamic response of DTC are maintained, and flux linkage and torque ripples are effectively reduced. Speed is estimated accurately, and sensorless operation is realized.


2011 ◽  
Vol 143-144 ◽  
pp. 350-354
Author(s):  
Jun Zhu ◽  
Xu Dong Wang ◽  
Bao Yu Xu ◽  
Hai Chao Feng

In order to improve the dynamic servo performance of PMLSM, a classical direct torque control (DTC) scheme based on bang-bang control is proposed in the paper. The proposed control method uses the bang-bang hysteresis controller formed a dual-closed loop control system, it contains torque loop and flux loop. The DTC control model was established and the simulation experiment was made. The simulation experiment results show that the DTC can improve the dynamic performance of PMLSM. It can reduce the ripples of speed and torque, so that it can provide more precision and accuracy servo performance.


2011 ◽  
Vol 383-390 ◽  
pp. 2628-2635
Author(s):  
Yu Ying Gao ◽  
Ming Ji Liu ◽  
De Ping Kong ◽  
Yun Gao Li

Direct torque control (DTC) has been widely used due to its advantages of less parameter dependence and faster torque response. However, in conventional DTC, there are obvious torque and flux ripples. This paper studies the influence of zero space voltage vectors on DTC system of permanent magnet synchronous motor (PMSM). The control model is established with Matlab/Simulink software. The simulation results show that the ripple torque can be reduced significantly when zero space voltage vectors are used. Meanwhile, the use of zero space voltage vectors can evidently decrease the switching frequency of the power switches as well as the switching loss. The achievements in this paper can provide a reference to improve DTC performance of PMSM.


Author(s):  
Muhd Zharif Rifqi Zuber Ahmadi ◽  
Auzani Jidin ◽  
Maaspaliza Azri ◽  
Khairi Rahim ◽  
Tole Sutikno

This paper presents the significant improvement of Direct Torque Control (DTC) of 3-phases induction machine using a Cascaded H-Bidge Multilevel Inverter (CHMI). The largest torque ripple and variable switching frequency are known as the major problem founded in DTC of induction motor. As a result, it can diminish the performance induction motor control. Therefore, the conventional 2-level inverter has been replaced with CHMI the in order to increase the performance of the motor either in dynamic or steady-state condition. By using the multilevel inverter, it can produce a more selection of the voltage vectors. Besides that, it can minimize the torque ripple output as well as increase the efficiency by reducing the switching frequency of the inverter. The simulation model of the proposed method has been developed and tested by using Matlab software. Its improvements were also verified via experimental results.


Sign in / Sign up

Export Citation Format

Share Document