Al-Najah National University Al-Najah National University

Electrical Engineering Department Electrical Engineering Department Speed Drive For Three-Phase Induction MotorSpeed Drive For Three-Phase Induction Motor

Presentation Presentation By

Eng.Mu’taz S. Al-Sheikh & Eng.Khalid Hammoudeh

Supervisor

Prof . Dr . Marwan Mahmmod

NNsyn syn = 120 f / P= 120 f / P

Changing number of poles (P) :

Methods for drive speed of IM :Methods for drive speed of IM :

This method requires a motor with special stator winding Changing line frequency (f) :Changing in (f) is affect in magnetization current & flux

Ф α 1/f

Changing line voltage (v):

Changing in (v) is affect in magnetization current & flux

Ф α v

The perfect method for drive is :The perfect method for drive is :

Methods for drive speed of IM :Methods for drive speed of IM :

Changing line voltage proportional to frequency

The ratio V / f constant.

The advantages of this method clearly in: The flux (Ф) remains constant. The torque remains constant at any speed

under the rated speed.

Note that : this project use the fourth

method for controlling under rated speed.

Characteristic curve for V/f constant :Characteristic curve for V/f constant :

Methods for drive speed of IM :Methods for drive speed of IM :

The general categories of (VSI) inverter:The general categories of (VSI) inverter:

Square wave inverter :

Voltage source inverter (VSI) :Voltage source inverter (VSI) :

The DC voltage Is controlled in order to control the magnitude of the AC output voltage and the inverter control the frequency.

The output voltage is a square wave voltage.

Voltage source inverter (VSI) :Voltage source inverter (VSI) : Pulse width modulation inverter (PWM) :

The DC voltage Is constant and the inverter control the magnitude of the AC output voltage and the frequency.

The behavior of one leg inverter.

To obtain any desired frequency , a sinusoidal control signal at desired frequency compared with a triangle wave .

Vcont > Vtri T+ IS ON Vcont < Vtri T- IS ON

The control wave & output wave form for three leg (PWM):The control wave & output wave form for three leg (PWM):

Three-phase pulse width modulation :Three-phase pulse width modulation : It is contain from three leg inverter .

Full power circuit for three phase IM drive .

PIN CONFIGURATION FOR THE CHIP :PIN CONFIGURATION FOR THE CHIP :

PWM generation chip (HEF-4752V)PWM generation chip (HEF-4752V)

Information of the pins :Information of the pins :

Pin 8 : drive signal for upper switching device for R-phase

Pin 9 : drive signal for lower switching device for R-phase

Pin 22 : drive signal for upper switching device for S-phase

Pin 21 : drive signal for lower switching device for S-phase

Pin 3 : drive signal for upper switching device for T-phase

Pin 2 : drive signal for lower switching device for T-phase

Pin 25: for determine the drive signal are in thyristor or transistor mode

Pin 24 : stop /start signal

Pin 7 : for the delay time

Pin 5 : for the reversing direction

Information of pinsInformation of pins

Pin 12 : to control the inverter output frequency

(f p12 = 3360*f0)

Pin 17 : control the output voltage of inverter

Pin 4 : setting for inverter switching frequency

Project Block Diagram :Project Block Diagram :

PWM Inverter (sequence of operation) :PWM Inverter (sequence of operation) :

Control Circuit of Project :Control Circuit of Project :

1. fFCT = 100 - 220 KHz ( results in varying output frequency from 30 to 85 Hz ) 2. fVCT = 300 KHz (results in obtaining V/f constant up to f01 =50 Hz).3. fOCT = 560KHZ (results in delay between the upper and lower transistor

operation = 0.0285 ms ). 4. fRCT = 560KHz (results in the maximum switching frequency = 2KHz )

Setting for Data Input :Setting for Data Input :

Isolator & Driver Circuit :Isolator & Driver Circuit :

The Results :The Results :• The minimum output frequency set to be 30Hz and the wave form of VRY is shown in fig

• The maximum output frequency set to be 85Hz and the wave form of VRY is shown in fig.

The Results :The Results :

• The 120˚ phase shift between R,Y phases :

Inverter Use in Project :Inverter Use in Project :

V / F = Constant , Showing in the table belowV / F = Constant , Showing in the table below

Measurements :Measurements :

VoltageVoltage V / F ratioV / F ratioFrequencyFrequency

1414 0.470.4730301616 0.460.4635351919 0.470.4740402020 0.40.450502020 …………50-8550-85

Thank you