Control and Analysis of Unified Power Flow Controller

5/22/2018 Control and Analysis of Unified Power Flow Controller

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CONTROL AND ANALYSIS OF UNIFIED

POWER FLOW CONTROLLER

By

K. VIMALAGOURIHT.NO: 13U01D4308

M. TECH (Power Electronics)


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ABSTRACT

This paper presents a control scheme and comprehensiveanalysis for a unified power flow controller (UPFC) on thebasis of theory, computer simulation and experiment.

A UPFC rated at 10 KVA is designed and constructed,which is a combination of a series device consisting ofthree single-phase pulse width modulation (PWM)converters and a shunt device consisting of a three-phase diode rectifier.

Experimental results agree well with both analytical andsimulated results and show viability and effectiveness ofthe proposed control scheme.


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FACTS

Flexible AC TransmissionSystem (Facts) is a newintegrated concept basedon power electronic

switching converters anddynamic controllers toenhance the systemutilization and powertransfer capacity as well

as the stability, security,reliability and powerquality of AC systeminterconnections.


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INTRODUCTION

Two main objectives of FACTS

Increase the TX capability ofAC line

Improved power transmissioncapability Improved system stability and

availability Improved power quality

Minimized environmentalimpact

Minimized transmission losses


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FACTS KEY DEVICES

STATIC SYNCHRONOUSCOMPENSATOR(STATCOM).

STATIC SYNCHRONOUSSERIES COMPENSATOR(SSSC)

.UNIFIED POWER FLOWCONTROLLER(UPFC).


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STATIC SYNCHRONOUS COMPENSATOR

It is a static synchronousgenerator as shunt static varcompensator whosecapacitive or inductive

current can be controlledindependent of the system

voltage.

The operation of the

STATCOM scheme isValidated in both thecapacitive and inductivemodes of operation.


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STATIC SYNCHRONOUS SERIES

COMPENSATOR

It is a static synchronousgenerator operated withoutan external energy sourceas a series compensator.

The o/p voltage is inquadrature with andcontrollable independentlyof the line current.

It is increase or decrease

the overall reactive voltagedrop across the line andthereby controlling thetransmitted electric power.


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SSSC

The main function of the SSSC is to regulate theTLpower flow PL. This can be accomplished by

either direct control of the line current or indirectcontrol by compensating for the TL impedance,Xs via a compensating injected voltage, Vs


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UNIFIED POWER FLOW CONTROLLER

(UPFC) The UPFC scheme consists of two basic switching

power converter namely shunt and series

converters connected to each other through a dclink capacitor.

The shunt converter operates exactly asSTATCOM for reactive power compensation and

voltage stabilization. The series converter operates as SSSC to control

the real power flow


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UNIFIED POWER FLOW CONTROLLER


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INTRODUCTION OF UPFC THE UPFC PROPOSED BY GYUGYI IS THE MOST

VERSITILE FACTS CONTROLLER FOR THEREGULATION OF VOLTAGE AND POWER FLOW INA TRANSMISSION LINE.

AN UPFC CONSISTS OF TWO VOLTAGE SOURCECONVERTERS.

1. SHUNT CONNECTED.

2. SERIES CONNECTED.

BOTH THE CONVERTERS CAN OPERATE IN ARECTIFIER MODE OR IN AN INVERTER MODE.


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UPFC

may control

voltage,impedence and

angle.

impact active and reactive

power flow in line.


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BASIC CONFIGURATION OF A UPFC

the upfc is installed between the sending end andreceiving end of a transmission line.

the upfc consists of a combination of a series deviceand shunt device, the dc terminals of which areconnected to a common dc-link capacitor.

the series device acts as a controllable voltage source.

the shunt device acts as a controllable current source.


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Contd.. the main purpose of the shunt device is to

regulate the link voltage by adjusting theamount of active power drawn from thetransmission line.

the active power can either be absorbed orsupplied by the series connected converter.

the shunt connected converter provides the

necessary power required, but also the reactivecurrent injected at the converter bus.


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CONSTRUCTION


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EXPERIMENTAL SYSTEM PARAMETERS

1. CONTROLLABLE POWER RATING (P) 10 KW

2. SERIES DEVICE CAPACITY(PINV) 1.1 KVA (=11%)

3 .RMS VOLTAGE OF VC (VC) +12 V/-12 V (=10%)

4. UTILITY LINE TO LINE VOLTAGE (V) 200 V

5. UILITY ANGULAR FREQUENCY (W0) 2*3.14*60 rad/sec

6. LINE INDUCTANCE (L) 1.0 mH (=10%)

7. LINE RESISTANCE (R) 0.04 OMH (=1%)


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CIRCUIT DIAGRAM


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RESULTS

Injected active power and Injected reactive power


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Line active power and line reactive power


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line voltage and line current


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MATLAB High-Performance language for technical

computing

Integrates computation, visualisation andprogramming

Matlab = MATrix LABoratory

Features family of add-on, application-specifictoolboxes


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SIMULINK Software Package for modelling, simulating

and analysing dynamic systems

Supports linear & Non-linear systems

Supports continuous or discrete timesystems

Supports multirate systems

Allows you to model real-life situations

Allows for a top-down and bottom-upapproach


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MATLAB VS SIMULINK

MATLAB SIMULINK


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OPPORTUNITIES control power so that it flows on the desired

routes.

increase loading capacity of transmission lines. prevent blackouts

improve generation produtivity.

Effective use of upgrading/uprating.


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ADVANTAGES OF A UPFC

A UPFC MAY BE REQUIRED WHENEVERTHE PROBLEMS OF VOLTAGE AND POWERFLOW ARE PRESENT.

THE POWER PLANNING STUDIES AREREQUIRED TO DETERMINE THE NEED OF ACONSUMER.

THIS TYPE OF DEVICE IS MOST USEFUL IN

THE OPERATION OF RESTUCTURED POWERSYSTEM.


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CONCLUSION

Most sophisticated power flow controller Expensive.

Gives better performance as compared toSTATCOM,SSSC and TCSC.

Provide simultaneous, real-time control of all basicpower system parameters (transmission voltage,impedance and phase angle) and dynamiccompensation of ac system.


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QUERIES?????.......


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Control and Analysis of Unified Power Flow Controller