A MICROPROCESSOR BASED SPEED CONTROL WITH SLIDING MODE FOR THE D.C. DRIVE

Abstract

This dissertation describes the application of the slid-ing mode control technique for the closed-loop speed control of a separately excited d.c. motor. A systematic procedure for the selection and the implementation of switching hyper-planes in the design of the variable structure controller for the d.c. drive is given. The ,.power source to the drive is a thyristorized three phase fully controlled bridge rectifier with a free-wheeling diode. The implementation of the control scheme is achieved using on Intel 8086 Microprocessor Trainer. The system control model is also simulated on the computer to study the influence of variations in the control parameters on the transient per-formance of the drive and to compare the response of such a drive with that of a conventional (PI-process) controlled drive. Chapter 1 contains the introduction where in the basic idea of the variable structure control is given and Chapter 2 provides a review of literature. Chapter 3 describes the design of controller', hardware and software for the micropro-cessor implementation. Chapter 4 deals with the experimental performance of the drive under transient and steady state conditions. Chapter 5 concerns the simulation studies and brings out the explanation of the simulation work. Chapter 6 gives the conclusions together with the suggestions to further improve the performance.