Sensorless Direct Torque Control of Induction Motor Using AI Based Duty Ratio Controllers

Among all control methods for induction motor drives, Direct Torque Control (DTC) seems to be particularly interesting being independent of machine rotor parameters and requiring no speed or position sensors. The DTC scheme is characterized by the absence of PI regulators, coordinate transformations, current regulators and PWM signals generators. In spite of its simplicity, DTC allows a good torque control in steady state and transient operating conditions to be obtained. However, the presence of hysterics controllers for flux and torque could determine torque and current ripple and variable switching frequency operation for the voltage source inverter. This paper is aimed to analyze DTC principles, and the problems related to its implementation, especially the torque ripple and the possible improvements to reduce this torque ripple by using a proposed fuzzy based duty cycle controller. The effectiveness of the duty ratio method was verified by simulation using Matlab/Simulink software package. The results are compared with that of the traditional DTC models.

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Improved Sensorless Direct Torque Control of Induction Motor Using Fuzzy Logic and Neural Network Based Duty Ratio Controller

IAES International Journal of Artificial Intelligence (IJ-AI) ◽

10.11591/ijai.v6.i2.pp79-90 ◽

2017 ◽

Vol 6 (2) ◽

pp. 79

Author(s):

Sudheer H ◽

Kodad SF ◽

Sarvesh B

Keyword(s):

Neural Network ◽

Fuzzy Logic ◽

Induction Motor ◽

Direct Torque Control ◽

Torque Control ◽

Duty Ratio ◽

Time Period ◽

Hysteresis Controller ◽

Remaining Time ◽

Selection Of

This paper presents improvements in Direct Torque control of an induction motor using Fuzzy logic with Fuzzy logic and neural network based duty ratio controller. The conventional DTC (CDTC) of induction motor suffers from major drawbacks like high torque and flux ripples and poor transient response. Torque and flux ripples are reduced by replacing hysteresis controller and switching table with Fuzzy logic switching controller (FDTC). In FDTC the selected switching vector is applied for the complete switching time period. The FDTC steady state performance can be improved by using duty ratio controller, the selected switching vector is applied only for the time determined by the duty ratio (δ) and for the remaining time period zero switching vector is applied. The selection of duty ratio using Fuzzy logic and neural networks is projected in this paper. The effectiveness proposed methods are evaluated using simulation by Matlab/Simulink.

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The Influence of Moment of Inertia to Induction Motor Rotation in Sensorless Direct Torque Control and Duty Ratio

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.313-314.55 ◽

2013 ◽

Vol 313-314 ◽

pp. 55-60

Author(s):

Ridwan Gunawan ◽

Muhammad Luniara Siregar ◽

Feri Yusivar

Keyword(s):

Vector Control ◽

Induction Motor ◽

Control Method ◽

Direct Torque Control ◽

Moment Of Inertia ◽

Torque Control ◽

Duty Ratio ◽

Motor Power ◽

Three Phase ◽

Torque Ripples

The vector control has become the first alternative in control of three phase induction motor. One of the vector control method which is commonly used is the direct torque control (DTC) method. However, this system has drawback due to the existence of torque ripples. The addition of the duty ratio control base on fuzzy logic can give better performance compared to conventional DTC. By doing an examination on DTC and duty ratio using small, medium and big capacities of three phase induction motors can be shown the influence from moment of inertia to rotor rotation. This paper uses MATLAB SIMULINK for the simulation study with three types of motor power, for example 1, 10 and 50 hp. It is shown that using the same parameters, a motor with a larger moment inertia gives a better performance in comparison to a motor with smaller moment of inertia.

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