DEVE PMENT OF FUZZY LOGIC BASED CHOPPER FED DC DRIVE

Abstract

This dissertation work deals with the design, development and performance investigations of the 8031 microcontroller based, multi-quadrant Chopper fed, closed loop controlled DC drive system, using fuzzy logic. The separately excited DC motor, which is loaded with separately excited DC generator with lamp load, is fed from a four-quadrant Chopper, which uses fast acting MOSFETs. The closed loop control is achieved by incorriorating ari inner current loop and outer speed loop. The speed error is processed by fuzzy controller to give current reference command. Current error is processed by another fuzzy controller to give T„,, time to Chopper. Both speed and current closed loop controls are realized through software in assembly language using 8031 microcontroller dedicated system. A simulation has also been done to check to correctness of the fuzzy logic controllers. The simulated drive consists of speed and current loops, both employing fuzzy logic controller. The response under the various conditions of loading has been found very good.