AC voltage regulation28-7.ppt

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Presented by,Ms. J.Uma Maheswari,

(91408415008)Raja College of Engg and Tech

Guided by,

Mrs. J.Raha Priya,

Lecturer/EEE

Raja College of Engg and Tech


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ABSTRACT To provide a solution to the sag/swell voltage

problems with the help of using renewable source so

that a regulated voltage is given to the load.

To well utilise the renewable source power so that

power consumed from the main supply is greatly

reduced.

To make available of uninterrupted power forever.

28 July 2010 AC Voltage Regulation using Renewable Sources 2


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INTRODUCTION

Reliable electrical power is the key to the economicdevelopment, industrial revolution , medical care and soon for a developing country

Electric power is generated by means of non renewablesources such as coal, oil and natural gas.

The non renewable sources are now-a-days exhaustedin rapid manner according to our usage. This leads todemand for AC power .


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CONTINUES.,

Also they cause pollution.

This forces the usage of renewable sources such as

solar energy and wind energy to produce power.

Voltage fluctuations cause a no. of harmful technicaleffects, resulting in disruption to production processes



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CONTINUES.,

Voltage fluctuation means the amplitude of rms

voltage changes during the disturbance occurs.

The number of voltage changes over a specified unit

of time.

Variations in generation capacity of power plant is

one of the root cause for the voltage fluctuations.



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LITERATURE REVIEW

The summary of literature review is as follows:

A digital proportionalintegral current control

algorithm is implemented to keep the current injected

into the grid sinusoidal and to have high dynamicperformance with rapidly changing atmospheric

conditions. [1]

To achieve buck and boost operation, couple a dcdcboost converter to the conventional VSI with no

sharing of components and semiconductor

functionalities, with less components. [2]



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CONTINUES.,Output power of the photovoltaic can be estimated

with an average value and ripple amplitude of the

detected current. [3]

PWM AC voltage regulator based on Cuk

converter is capable of correcting voltage sags down

to 60% and voltage swells up to 30%, with the output

returning to its nominal value [4]



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EXISTING SYSTEM

The AC power is generated by means of non

renewable sources such as coal, fossil fuels etc.,

Non-renewable energy sources are being depleted at a

rapid rate in these days due to large demand of power.

So, availability of power at constant rate gets

affected.



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CONTINUES.,

Transformer tapings may be used.

But, Number of windings used in secondary side is

more.

Electromechanical voltage regulator may be used.

Auto Transformer is used to step down or step up the

output voltage for regulation.



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CONTINUES., Buck boost converter may be used for voltageregulation .

But usage of more power devices leads to more power

loss while regulating the power.

Drawbacks of CVTs (constant voltage transformers)are their larger size, audible humming sound, and high

heat generation and electromagnetic interference

problems.

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BLOCK DIAGRAM


Sunlight

Speed Sensor3 ,50 Hz AC

SUPPLY

REFERENCE SPEED

PWM

CONTROLLER

3 PHASE

CONVERTER

RENEWABLE

POWER

3 PHASE

PWM

INVERTER

3PH

IM


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DESCRIPTION

Here, a part of power generated by means of nonrenewable source is fed from main supply which isconverted into DC .

Power generated by means of renewable source is notfeasible to run a load at necessary circumstances as such.

A part of power generated by means of non renewablesource is fed to the inverter along with the renewablesource power.



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CONTINUES.,

Here 3 rectifier is used to convert available AC source

into DC source

Power generated by renewable power is also added

with it, then both of them fed to 3 Inverter.

Three phase PWM Inverter is used to convert DC into

AC.



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CONTINUES., Fluctuations in any one of the supplies will

compensate other and capable producing constant

supply to the load

Speed sensor may used to sense the speed of

Induction motor which is compared with the

reference and accord to the error, PWM signals aregenerated in PWM controller to activate PWM

inverter.



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CONTINUES.,Here PI Controller is used to generate a reference

signal for PWM signal generation.

A digital ProportionalIntegral algorithm isimplemented to keep the output of inverter insinusoidal nature with elimination of offset error andovershooting.

This digital PI Controller control algorithm havehigh dynamic performance with rapidly changing

voltage.28 July 2010 AC Voltage Regulation using RenewableSources 15


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CONTINUES.,

The speed of Induction motor is measured andcompared with Reference speed .

If reference speed and actual speed are equals then

there is no change in firing angle of inverter.

In case both are not equal then firing angle may be

varied to compensate low voltage problem.

Finally required voltage is fed to the load to meet its

requirements.28 July 2010 AC Voltage Regulation using Renewable Sources 16


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CONTINUES., Here induction motor is used as a load which runs at a

constant speed due to fluctuations free voltage.

Here, asynchronous machine is used to run at 1200 rpmwith power of 4KW with input rms voltage of 400 V with

supply frequency of 50 Hz.



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IMPLEMENTATION



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The scale factor for X-axis : one block = 0.1 sec

The input rms voltage 183V(voltage from nonrenewable source)


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The voltage which is generated by means of renewable power

which is varying at the period of 0.3 second due to change intemperature from 20C to 60C from 195V to 250V



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The non renewable voltage which is varying at the period of 0.5

second due to fluctuations from 550V to 250V



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Simulation result of summation of non renewable and

renewable voltage



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Simulation result of the speed of rotor



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The voltage which is generated by means of renewable power

which is varying at the period of 0.5 second due to change in

temperature from 50C to 100C from 240V to 300V



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The non renewable voltage which is varying at the period of 0.3

second due to fluctuations



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Simulation result of the speed of rotor



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SIMULATION DIAGRAM FOR A SYSTEM

WITHOUT USING RENEWABLE SOURCE



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Simulation result of a system only with non renewable

source voltage



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Simulation result of decrease in speed of rotordue to

voltage fluctuations



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ADVANTAGES Conservation of non renewable source is possible.

Make use of renewable source in efficient manner.

Output Voltage is free from fluctuations

Capable of having uninterrupted power.

Power consumed from main supply is dramatically

reduced. Thus we save power.28 July 2010

AC Voltage Regulation using RenewableSources 30


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CONCLUSION By this system we regulate the voltage which is fed to

the load with the help of renewable source power.

Solution to the sag/swell voltage problems is

achievable.

Power quality issue may be solved.



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CONCLUSION

To provide a stabilized output to the load even there is

fluctuations in the input power.

By providing a regulated voltage to the load, the load

may be operated at required conditions.

Conservation of non renewable source is possible.



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REFERENCES

[1]Selvaraj And Rahim: Multilevel Inverter For Grid-connected Pv System Employing PIController, IEEE

Transactions On Industrial Electronics, Vol. 56, No. 1,

January 2009

[2] Diode-Assisted BuckBoost Voltage-Source

Inverters ,Feng Gao, Poh Chiang Loh, Remus

Teodorescu, IEEE Transactions On PowerElectronics, Vol. 24, No. 9, September 2009



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CONTINUES.,

[3] T. Esram and P. L. Chapman, Comparison of photovoltaicarray maximumpower point tracking techniques,IEEE Trans.

Energy Convers., vol. 22, no. 2, pp. 439449, Jun. 2007.

[4] Jose Hoyo a; Hugo Calleja a;Janeth Alcala, High-qualityoutput PWM AC voltage regulator based on Cuk converter,International Journal of Electronics, Volume 92, Issue 4 April2005 , pages 231 - 242

[5] S. J. Park, F. S. Kang, M. H. Lee, and C. U. Kim, A newsingle-phase fivelevel PWM inverter employing a deadbeatcontrol scheme,IEEE Trans.Power Electron., vol. 18, no. 18,

pp. 831843, May 2003.

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AC Voltage Regulation using RenewableSources 34


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CONTINUES.,[6] Ali M. Eltamaly, A. I. Alolah, R. Hamouda, and M. Y.

Abdulghany, A Novel Digital Implementation of ACVoltage Controller for Speed Control of Induction Motor,

World Academy of Science, Engineering and Technology54 2009

[7] G. Carrara, S. Gardella, M. Marchesoni, R. Salutari, andG. Sciutto, A new multilevel PWMmethod: A theoretical

analysis,IEEE Trans. Power Electron., vol. 7, no. 3, pp.497505, Jul. 1992.

The Book named, Power Electronics ,by Bimbhra



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THANK YOU

AC Voltage Regulation using Renewable

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AC voltage regulation28-7.ppt