By

Turki al saleh

Harmonic Reduction in the Utility Interface SCR Rectifier

Under Supervision of

Dr. Ali M. Eltamaly

: Abstract

Improved approach to reduce harmonics in the three-phase controlled rectifier is presented.

The injection current path uses zigzag transformer and boost converter to control the injection current.

Complete implementation of boost converter

Experimental results have been used to verify the mathematical and simulation results.

Harmonics:

harmonics can be defined as a sinusoidal component having frequencies that are an integral multiple of the fundamental frequency.

S C RC o n v erte r

I a

Harmonic Reduction in the three-phase controlled rectifier

Harmonic Reduction by Using R-L in Injection Path

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Experimental Results

Simulation Results

Harmonic Reduction by Using Boost Converter

Implementation of Boost Converter

1- Control Circuit: DC Power Supply. Voltage Controlled Saw-tooth Oscillator and

Comparator.

2- Isolation Circuit

3- Power Circuit

Boost Consist-:

The Component Required for Power Supply:

Transformer 220/ 24-0-24

Two Regulator 7815 & 7915

Two capacitors 100uF & two capacitors 10uF

Bridge diode

The Power Supply Module

Voltage Controlled Saw-tooth Circuit Components-:

PUT 2n6027

Two OP-amp 741

Diode

Capacitor 10nF

Two Potentiometer 100k

Resistors

Voltage Controlled Saw-tooth Oscillator and Comparator Circuit:-

Isolating Circuit Components-:

Transformer 220/ 18-0-18

Optocoupler 4N32

Regulator 7815

Two capacitors 10uF

Bridge diode

Isolating Circuit Module

2 -Power Circuit Component-:

Transformer

Inductance

MOSFET

Capacitor 470uF(250V)

High current diode

bridge diode

Power Circuit of Boost Converter

Control Circuit

IsolatingCircuit

PowerCircuit

BOOST

The Input & Output of Control Bridge

Experimental Results:

The Output of Voltage Regulators 7815 and 7915

The Saw-tooth Waveform and Control Pulse

The Input & Output of Pulse

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Vdn

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Vfn

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Conclusions :

We got low THD with no power losses.

The wave form after reinjection is very near to sinusoidal.

Experimental results agrees with simulation results.