MICROCONTROLLER BASED CHOPPER FED DC DRIVE

Abstract

DC machines are characterized by their versatility. Because of the ease with which they can be controlled, systems of DC machines are often used in applications requiring wide range of motor speeds or precise control of motor output. A major demand of the present day industries is to have precise and wide range of speed control for drives with good speed resolution and reproducibility. The present work deals with the implementation of a fully digital system using an Intel 8031 microcontroller and some random logic for speed control of a DC motor which is fed by a chopper circuit employing three thyristors. The drive system - DC motor coupled to DC generator, is tested for both the open-loop and closed-loop performance. Chapter 1 is introduction, in which chopper control of DC drives and digital control of power converters is dealt in brief. Chapter 2 is the literature review. Chapter 3 about the INTEL 8031 microcontroller, in which the salient features of this microcontroller and its comparison with INTEL 8085AAP is given. Chapter 4 gives a wide review of the concepts of New Chopper Circuit. Chapter 5 gives a detailed idea of the hardware circuits used. Chapter 6 gives a perspective in the logic used for controlling the chopper output voltage. Chapter 7 is devoted to detailed study of performance of the drive both in open-loop and closed-loop. Chapter 8 is related to conclusions reached and further scope of work related to improvement of system developed.