ST. AUGUSTINE, TRINIDAD & TOBAGO, WEST INDIES FACULTY OF ENGINEERING
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Department of Electrical & Computer Engineering
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BSc. in Electrical & Computer Engineering
ECNG 2005
Lab and Project Design III
Individual Design Project
PI Control of a DC Motor
Keshan Kevin Babooram
810001070
Group F
Course Lecturer: Marcel Byron
Date Submitted: April 20th, 201
Abstract
This project is based on the PI control of a DC motor with consideration given to a cooling fan application. This design also utilizes microprocessor as the controller. The designed system will have a means of overcurrent protection as a form of motor protection and will also use the rotary method of motor speed sensing. Also motor speed displayed 7 segment displays. Within project there will be algorithms that are to be implemented and the interfacing circuitry that is to be used when interfacing with the microprocessor.
Table of Contents Abstract i Introduction 6 Background theory 7 DC motor 7 Control schemes 7 Current sensing 9 Motor protection 10 Implementation of control algorithm 11 Motor speed measurement 12 Design Brief 13 Production Design Specification 15 Performance 16 Environment 16 Product life cycle 16 Safety and standards 17 Testing 17 Conceptual Design 17 Control design 19 Microprocessor design 20 Controller design 21 Mathematically modelling the system using the step response 21 Determination of suitable performance specs 23 Determination of key circuit parameters 26 Finding the Armature Resistance 26 Finding the Armature Inductance 26 Finding the motor torque constant and the back EMF constant 27 Finding the Time Constant for the system in the electrical domain 28 Finding the Inertia 28 Justification of choice of the controller 29 Implementation of a PI controller
References: "DC Motor Protection." Electric Motors and Industrial Electric Motors by OEM. http://www.ohioelectricmotors.com/dc-motor-protection-804 (accessed April 16, 2012). "DC Motor Theory - Developer Zone - National Instruments." NI Developer Zone. http://zone.ni.com/devzone/cda/ph/p/id/52 (accessed April 16, 2012). Goodwin, Graham C., Stefan F. Graebe, and Mario E. Salgado. "PID Theory Explained - Developer Zone - National Instruments." NI Developer Zone. http://zone.ni.com/devzone/cda/tut/p/ "Closed Loop Speed and Position Control of DC motors | IKALOGIC."IKALOGIC. IKALOGIC Electronic Solutions, n.d. Web. 10 Apr. 2012. <http://www.ikalogic.com/closed-loop-speed-and-position-control-of-dc-motors/>. Babooram, Keshan. “Design Project -2004.” 2011. MicroChip. n.d. http://ww1.microchip.com/downloads/en/devicedoc/41233a.pdf (accessed 4 13, 2012).