Modeling simulation analysis and real time verification of PWM techniques for DTC based induction motor drive using AI techniques

Abstract

Variable frequency drive is widely used in industrial control purposes ranging from smaller to larger applications Advancements in power electronics has greatly reduced the cost and has also improved the performance of the variable frequency drives Control of avariable frequency drive can be divided into scalar control and vector control Thescalar control is the simplest method which does not deliver high dynamic performance But the vector control is able to control the position of the voltage current and flux vectors It significantly improves the dynamic performance of the drive Because of these reasons vector control drive has become an industrial standard The pulse width modulation technique plays an important role to control the variable frequency drive Different types of PWM techniques are used to control the drive such as SPWM SHEPWM and SVPWM Upon the analysis of different modulation techniques used in drives the space vector PWM technique is found to be highly suitable for vector control drives because it has several advantages over other modulation techniques such as simplicity degree of freedom flexibility and implementation In SVM switching intervals and duration of switching state is calculated by using vector calculation Vector control can be divided into field oriented control feedback linearization control and direct torque control Among these the direct torque control is the most popular method in vector control drive Direct Torque Control DTC does not require any coordinate transformations voltage modulation block or current control loops Because of these features this method has simple structure and good dynamic behavior At the same time this method has some disadvantages such as while starting and low speed conditions the contribution of back EMF is very low due to which the torque ripples are increased Flux distortion also happens while stator flux vector has been changed over a large angle newline newline newline