Presented byLajin B S

Jiji PrabhashMeghana Jayakumar

Nithin JosephMalini Mohan

Guided by: Mr. Rahul R S

DESIGN OF VARIABLE FREQUENCY DRIVE

FOR SPEED CONTROL IN SINGLE PHASE INDUTION MOTOR

OVERVIEW OF PRESENTATION AIM INTRODUCTION FUNCTIONAL BLOCK DIAGRAM WORKING PRINCIPLE

CONTND… FIRST PHASE ADVANTAGES DISADVANTGES APPLICATIONS

AIM

Design of variable frequency drives for speed

control in single phase induction motor

PHASES OF PROJECT

FIRST PHASE

• Experimental set up of the drive using basic knowledge

SECOND PHASE

• Microcontroller programming

THIRD PHASE

• Hardware design, assembling & installation

INTRODUCTION Most of the industries use induction motors as the

drives Rising energy price create a need for energy efficient

motor VFDS are useful in energy saving It reduces the motor speed as demand decreases VFDs consists of Electronic actuator-controller Driving electrical machines – motor Driven machine – pump, fan, blower…

FUNCTIONAL BLOCK DIAGRAM

WORKING PRINCIPLE

Torque of IM depends on flux

Flux α V/f ratio

Hence torque α V/f ratio

Speed = 120 * f/ P

With load change, speed also changes

By retaining V/f ratio constant, torque is

maintained

TORQUE SPEED CHARACTERISTICS OF IM

Serving as the prime power sources for a seemingly

limitless array of small-horsepower applications in

industry and in the home.

Single phase AC electrical supply is what is typically

supplied in homes, three phase electrical power is

commonly only available in a factory setting.

Correctly sized and rated -- can last a lifetime with little

maintenance.

WHY SINGLE PHASE INDUCTION MOTOR?

PWM INVERTERS? Characterized by constant amplitude pulses Width of these pulses is modulated Different PWM techniques – Single pulse

modulation, Multiple pulse modulation and

Sinusoidal pulse modulation These techniques differ each other in harmonic

content Choice – on permissible harmonic content in

input

SINUSOIDAL PULSE WIDTH MODULATION Pulses over half cycle of unequal widths are generated Pulse width is a sinusoidal function of angular position of each cycle By comparing a sinusoidal wave against a triangular carrier wave Simple and ease of implementation No: of cycles is decided by ratio of triangular carrier frequency to that of modulating sinusoidal frequency

WAVEFORMS

CONTND…

PWM inverter model has four sections

o Power supply section

o Power circuit section

o Load circuit section

o Gate control section

BASIC CIRCUIT

HARDWARE

Bridge Rectifier

DC Chopper

PIC Microcontroller

Basic circuit

Keypad & LCD Connection

Dead Band time Generator

3-Phase Bridge Driver

IGBT 3-Phase Inverter

COMPONENTS Diode rectifier- KBPC 35-10, Maximum recurrent

peak reverse voltage 1000 V. Maximum average forward rectified current 35 A

Supply source – 220V, 50 Hz ac Power circuit section – 4 No: of 2MBI50L-120

IGBTs, 1200V, 50 A,400 watts, Vgth > 20V Load circuit section –single phase induction motor Gate control section- PIC 16F877A, 5V Gate driver – IR21363, Gate drive supply

voltage 10-20V

EXPERIMENTAL SETUP

Software used- PROTEUS Microcontroller – 8051

PROGRAMORG 0000HST:JNB P1.0,A1JNB P1.1,A2JNB P1.2,A3JMP STA1:CLR P2.0CALL DELAY1SETB P2.0CALL DELAY1JNB P1.1,A2JNB P1.2,A3JMP A1DELAY1:

MOV R0,0FHL1:MOV R1,0FFHDJNZ R1,$DJNZ R0,L1RETA2:CLR P2.0CALL DELAY2CALL DELAY1SETB P2.0CALL DELAY2CALL DELAY1JNB P1.0,A3JNB P1.2,A1

CONTND…

JMP A2DELAY2:MOV R0,0FHL2:MOV R1,0FFHDJNZ R1,$DJNZ R0,L2RETA3:CLR P2.0CALL DELAY3CALL DELAY1CALL DELAY3CALL DELAY1CALL DELAY2

CONTND…

SETB P2.0CALL DELAY3CALL DELAY3CALL DELAY1CALL DELAY2CALL DELAY1JNB P1.0,A1JNB P1.1,A2JMP A3DELAY3:MOV R0,03FHL3:MOV R1,0FFHDJNZ R1,$DJNZ R0,L3RETEND

CONTND…

ADVANTAGES Rising energy prices creates a need for energy

efficient motor To reduce energy losses we select VFDs Improved operating performance Good control capability Efficient energy saving Consume less energy

DISADVANTAGES

High cost System resonance Increased noise& vibration Shortens life Reduce service factor

APPLICATIONS Boiler pumps , fans& HVAC system Cooling towers Compressors Stairway & packing ventilation Kitchen hoods Roof top units Air handlers Elevators & escalators

THANK YOU