Prepared by : 1. Goti Tushar ( ) 2. Pandya Uday ( ) 3. Mangukiya Jayesh( ) Guided By: Prof.M.R.Vasavada

Contents : 1.Induction Motor  General Aspects  Parts Of Ac Motor  Construction  Principle Of Operation  Specification Of I.M.  Literature View 2. Speed Control Of I.M.  Necessity Of Speed Control  Methods Of Speed Control 3.Project details  Block Diagram and Description  Circuit Diagram  Components of the Circuit  Limitations Ac Voltage Controller

General aspects: A induction machine can be used as either a induction generator or a induction motor. Induction motors are popularly used in the industry Focus on three-phase induction motor Main features: cheap and low maintenance Main disadvantages: speed control is not easy

Parts Of Ac Motor:

Construction : The three basic parts of an AC motor are the rotor, stator, and enclosure. The stator and the rotor are electrical circuits that perform as electromagnets. According to rotor construction,Induction motor types :  Squirrel cage type Wound rotor type  Wound rotor type In Our Project, we choose the Speed Control Of Squirrel Cage Induction Motor. Principle of operation : connected When a 3 phase stator winding is connected to a 3 phase voltage supply, induced which will induced 3 phase flux in the stator.. These flux is called as Rotating magnetic field. This magnetic field cuts the rotor windings and produces an induced voltage in the rotor windings.

Specification of I.M. MotorSQIM Output capacity(kW/H.P.)3HP Voltage220/415V AMP. 4.6A RPM1440 HZ50 Connection Type:Star-Delta Efficiency84 DUTYS1 InsulationClass F/H ENCL.TEFC/TE TEMP. 88°C

Literature View 1. Design And Fabrication Of 3-Phase Ac Voltage Controller Fed Speed Control Of 3-PHASE S.Q.I.M. International Journal of Engineering Research & Technology (IJERT) Vol. 1 Issue 6, ISSN: ,August –  This paper presents the hardware implementation for speed control of 3-phase induction motor by using TRIAC-based AC voltage controllers with line commutation technique.  In their results they conclude that the stator voltage control method is used which offers limited speed drives. Based on the advantages and disadvantages of this method, they are used for low power drives, and also where flexibility in control, fast response is required.

Conti Speed Control of 3-Phase Squirrel Cage Induction Motor by 3-Phase AC Voltage Controller Using SPWM Technique International Journal of Engineering Research & Technology (IJERT) Vol. 3 Issue 1, January IJERT, ISSN:  In these paper, Researcher discusses the Modeling and simulation of 3- phase Ac voltage controller for speed control of I.M. With the help of SPWM technique speed control of induction motor is very effective and harmonic free.  The disadvantages in SPWM technique can be eliminated with the help of space vector modulation. Speed control of IM is achieved with help of controlling the angle of ac voltage controller and for closed loop reference speed can be achieved with SPWM technique. simulation model & its rms o/p voltage reading of practical, mathematical and matlab simulink results are compared.

 Necessity Of Speed Control Of 3- phase Induction Motors : It ensures smooth operation. It provides torque control and acceleration control. Different processes require the motor to run at different speeds. It compensates for fluctuating process parameters. During installation, slow running of the motors is required. All these factors present a strong case for the implementation of speed control in Induction Motors.  Main Disadvantage: The major disadvantage of I.M. is that its speed control is not Easy. For its speed control requires many kind of power electronics devices and having Its complex circuitry. Also while using Power electronics Semiconductor Switches, it introduces harmonics in system.

 Methods Of Speed Control  3 phase I.M. are admiringly suited to fulfill the demand of loads requiring substantially a constant speed. How ever, need adjustable speeds for their efficient operation.  The various methods of speed control are as under: 1. Stator Voltage Control 2. Stator Frequency Control 3. Stator Voltage Control and Frequency Control 4. Stator Current Control 5. Static Rotor Resistance Control 6. Slip-Energy Recovery Control

From that methods, we were chose the method of Speed Control are as given below: 1. Stator Voltage Control using Three phase Ac Voltage Controller With RF Modules

1.Stator Voltage Control using Ac Voltage Controller

DISCRIPTION : power supply to microcontroller(89s52) which drive the scr driver to vary firing angle of anti parallel scr bridge as firing angle of scr vary the voltage across motor will vary. And such manner speed of IM will vary.

Circuit Diagram:

Sub-Circuits :  Micro controller 89s52:  Controller Power Supply Circuit Components & Specifications :  Zero Crossing Detector Circuit  SCR Gate Driving Circuit  Reset circuit  Transmission Circuit  Receiving Circuit

Block Diagram of 89s52:

 Pin Diagram:

Features Compatible with MCS-51 Products 8 K Byte of In System Programmable (ISP) Flash Memory Endurance: 10,000 Write / Erase Cycle 4.0V to 5.5V Operating Range Fully Static Operation: 0Hz to 30 MHz Three level Program Memory Lock 256 x 8-bit Internal RAM 32 Programmable Input / Output Lines Three 16 bit Timer / Counters Eight Interrupt Sources Full Duplex UART Serial Channel Low power Idle and Power down Mode Interrupt Recovery from Power down Mode Fast Programming Time Flexible ISP Programming (Byte and Page Mode )

Controller Power Supply Circuit Components & Specifications : Components(Specifications Single Phase(0-12) V, 1.5 A DiodeIN4007 Capacitor1000 µF, 25 V Voltage Regulator ICIC 7805 Heat Sink

Zero Crossing Detector Circuit Components & Specifications : ComponentsSpecifications Transformer(0-12)V, 500mA Resistor470 Ω Opto -IsolatorMCT2E Resistor10 kΩ

SCR Gate Driving Circuit Components Specifications: ComponenetsSpecifications TriacBTA16, 16A Opto-coupler4N36 DiodeIN4007 Resistor100 Ω

Reset circuit ComponenetsSpecifications Resistor10kΩ Capacitor10 µF,63V Push back switch-

Transmission Circuit Pin NoFunctionName 1Ground (0V)Ground 2Serial data input pinData 3Supply voltage; 5VVcc 4Antenna output pinANT

Receiving Circuit

Limitations of Ac voltage Controller: There has to be limited range of speed control of induction motor. The RMS output voltage contains harmonics which undesirable for operation of motor. The input supply power factor is low. The starting torque must be low. The motor attached to the ac voltage controller is usually never started with high starting torque

References :  IEEE Journal  Power electronics Book, Prof. P.S,Bhimbhra Khanna Publication  Other Research Organization Journals.  