SPEED CONTROL OF DC MOTOR USING PWM TECHNIQUE

Transcription

1 SPEED CONTROL OF DC MOTOR USING PWM TECHNIQUE Shubham Naik 1 1 Electrical Engineering Abstract DC motors are widely used in industries where high speed torque requirement. Because of it characteristics & features it is very much in constant speed application demand. PWM based is electronic control method which gives smooth speed control as per load regulation. Arduino board is heart of system having program for counting speed revolutions of motor through LM 393 speed sensor. Controlling the duty cycle of waveform similar to controlling terminal voltage applied to motor. Keywords Speed control, Arduino, LM393, DC motor, PWM I. INTRODUCTION High performance motor drive system must have dynamic speed command tracking as per load regulating. Device which converts electrical energy to mechanical energy called as a motor and which uses dc supply to produce mechanical output is DC Motor. Higher efficiency, better overload & peek voltage characteristics, speed-torque characteristics due to this motor are useful for constant speed characteristics. Because of simplicity, ease of application, cost favor used in industrial, robotics and defense application Several method to control speed of DC motor electronically PWM,PID,PI Fuzzy etc. Purpose of developing a control system to enable stable & reliable supply. By changing pot value firing MOSFET change and change in voltage applied to Motor.Hence speed of motor is smoothly controlled. II. DIFFERENT TECHNIQUE OF SPEED CONTROL OF DC MOTOR Due to torque-speed characteristics, it is compatible with most mechanical loads.hence DC motor controllable wide range of speeds by proper adjustment of armature voltage and filed current. Flux per pole (Flux control) Armature voltage control (Voltage control ) Above both methods having some drawbacks like large amount of energy wasted in controlling due to which speed control efficiency is decreased.semiconductor components like GTO, Thyristors,MOSFET have been used as electric switching. This method provide armature voltage regulation by PWM pulse through PWM controller.it helps to provide greater speed reliability,quick response, Higher efficiency. In this PWM control technique is used for speed control DC motor, controlled voltage fed to motor with MOSFET.By changing position of POT change in the voltage applied to motor hence change in speed of motor. DOI: /IJMTER MLMY 114

2 II. BASIC BLOCK DIAGRAM Figure 1 Basic Block diagram for Speed control of DC motor using PWM. SCHEMATIC DIAGRAM Figure 2 Schematic diagram for speed control III. HARDWARE DESIGN & DETAILS Power supply: Power needs transformer of 230/24 V supply. Power supply consist of above rated transformer, bridge rectifier,5 volt IC.For bridge calculation of average current per diode important. I d c =0.90 Average current per diode = 0.5 x 0.90 = 0.45 Amp C = (I x T)/V, V=5v,I=1A T= 3.18 x 10-3 C= 637 Microfarad Hence Choose Bridge Rectifier according to above values. Figure 3 Design of Power supply using All rights Reserved 115

3 M393 sensor with encoder disc Basically it is speed sensor for measuring actual speed of motor. This device consists of independent voltage comparator that is operated at designed voltage from 2v to 36 v. Following are features: 1. Single supply or dual supplies 2. Current drain independent supply 3. Low input Bias current 4. Low O/P saturation voltage 5. Compatible with TTL,MOS & CMOS Sensor attached with encoder disc obtained from optical mouse having four slots.one side having LED & other side of sensor having phototransistor. IV. ARDUINO UNO Arduino UNO 328 microcontroller is heart of overall system.it has 14 digital input/outputs pins,6 analog inputs,16mhz quartz crystal,usb connection etc. Arduino is user-friendly microcontroller just simply connection to computer with USB cable.it uses Arduino IDE software for programing. Technical specification: 1. Operating voltage = 5 V 2. Input voltage = 7-12 V 3. Digital I/O pins = PWM I/O = 6 5. Clock speed = 16 MHz V. MOSFET & POTENTIOMETER The metal oxide field semiconductor filed effect transistor is type of Field effect transistor (FET).MOSFET has insulated gate terminal & voltage applied to this terminal decides conductivity of the device.the ability to change conductivity of this device by changing voltage applied to it. Hence it is uses as switching voltage applied to DC motor.rotary pot is used as changing value & adjust speed of motor. VI. TEPS INVOLVING IN PROJECT Following steps are involved in project. 1. Arduino interface with LCD. 2. Arduino interface with speed sensor for speed measurement. 3. PWM based control Arduino interface with LCD Here Arduino UNO 328 interfaces with 16x 2 LCD. 1. Turn on LCD. 2. Select input and output pins. 3. Select line 4. Enter require letter Hardware requires are jumper wires,lcd board with breadboard for connection& Arduino.Program download from PC to board by USB cable and text message displayed on All rights Reserved 116

4 Arduino interface with speed sensor Here UNO 328 interfaces with speed sensor. 1. Select pulses per turn 2. Assign input pin2 for digital pulses from sensor 3. Counter start 4. Assign interrupts value 5. RPM formula 6. Print on serial monitor PWM Control circuit 1. Select pulses per turn 2. Assign input pin2 for digital pulses from sensor 3. Assign pot pin A0 for Ana log input 4. Assign LCD pins 5. Assign PWM output pin Counter increment 7. RPM formula 8. Print RPM & pot value on serial monitor 9. Print RPM on LCD 10. HIGH pin Use delay 12. LOW pin 12 Figure 4 Actual results on LCD VII. RESULTS Table 1 Speed variation results Sr.no Serial monitor LCD speed Tachometer Voltage current speed speed All rights Reserved 117

5 Table 2 PWM results Sr.no Pot value Speed VIII. CONCLUSION The hardware makes use of Arduino microcontroller, speed sensor, Power supply and MOSFET for electronic armature voltage control. Speed control using PWM was smooth control which gives ease of control of speed. Results were obtained from various pot positions.measured RPM was displayed on LCD as well as Serial monitor and programmed in IDE software. Results are obtained and verified with actual measured speed using Tachometer. Both speeds were matching together. REFERENCES [1] Masoom Raza, Mohd. Kamil, Pushpendra Kumar Speed control of DC motor using PWM International Journal of Advanced Research in Computer and Communication Engineering [2] Atul Kumar Dewangan, Nibbedita Chakraborty, Sashi Shukla, Vinod Yadu PWM based automatic closed loop speed control of DC motor International Journal of engineering Trends and technology - Volume 3 Issue [3] Manoj Kumar Swain, Bibhuti Nemalpuri, Deepak Kumar Das and Aieshwarya Nath Four quadrant dc motor speed control using Arduino International Journal of Modern Trends in Engineering and All rights Reserved 118