power flow control with upsc

8/7/2019 Power Flow Control With Upsc

1/23

Authorised By

SANTOSH BHARADWAJ REDDY

Email: [email protected]

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mailto:[email protected]:[email protected]


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ABSTRACT:

In the early days of power transmission, problems like voltage

deviation during load changes and power transfer limitation

were observed due to reactive power unbalances. Today these

problems have even higher impact on reliable and secure power

supply in the world of globalisation and privatisation of

electrical systems and energy transfer.

Energy is the basic necessity for the economic

development of the country. The rate of growth of electricity

usage through out the world is increasingly high in the last ten

years. In recent years ecological concern and high installation

costs have put constraints over construction over head lines in

many countries; there by forcing existing to be used more

efficiently & effectively. AC transmission systems are thoughtof as being inflexible.

This paper presents a new approach for realizing a smart, fault

tolerant, controllable and asset efficient power grid through the

use of massively manufactured communications-enabled

sensors, power converter and actuator networks. One example is

Smart wires implemented using many modules of a unified

power flow controller (UPFC) device that can be clamped on aexisting power lines, and can be operated so as to control the

impedance of the conducters, reactive power-thus controlling

power flow. This approach promises important system-wide

benefits including-increased line and system capacity; increased

reliability; improved asset utilization; improved operation under

contingencies; reduced environmental impact; incremental

deployment; and rapid implementation.

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INTRODUCTION:

Nowadays, it is becoming increasingly

difficult to build new transmission lines, due to restrictions

regarding environment and financial issues. Besides that,

electrical energy consumption continues to increase, leading to a

situation where utilities and independent system operators have

to operate existing transmission systems much more efficiently

and closer to their stability limits. This leads to the study of

FLEXIBLE AC TRANSMISSION SYSTEM (FACTS).

The need to augment existing transmission

network is overdue as networks have not grown commensurate

to generation. This has become particular series after

introduction of independent power produces (IPP) & capacitive

generation (CG) are connected to the existing networks. There is

a need to review border aspects of planning transmissionsystems the need to have better discipline and control over the

system to cater to network constraints on one hand to stringent

requirements of the consumer on the other. The use of newer

technology available today including solid state devices such as

FACTS, which are entering the power sector, have also to be

considered in any future planning/augmentation studies.

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Why is energy needed..

How can we transfer power more Flexible..

What is meant by FACTS.

How it transfers power more Efficiently

BASIC EQUATION

P = (Vs*Vr/ X) sin

BENEFITS OF UTILISING FACTS DEVICES:

Better utilization of existing transmission system assets.

Increased transmission system reliability and availability.

Increased dynamic and transient grid stability and reduction of

loop flows.

Increased quality of supply for sensitive industries.

Environmental benefits.

Less cost

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PURPOSE OF FACTS

CONNECTION OF GENERATION

CONNECTION F

ISOLATED LOADS

FACTS

FACTS

INTERCONNECTION BETWEEN

THE WITHin AGRID(SAME FREQUENCY)GRIDS(DIFFERENT FREQUENCIES)

facts

facts 50Hz 50 Hz 50 Hz

60 Hz

INCREASE EXISISTING GRID UTILIZATION

New transmission lines are expensive

And are not permitted.

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Facts

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IEEE DEFINATIONS:

FACTS :

A.C TRANSMISSION SYSTEM INCORPORATING THE POWER

ELECTRONIC BASED AND OTHER STATIC CONTROLLERSTO ENHANCE

CONTROLLABILITY AND INCREASE POWER TRANSFER CAPABILITY

FACTS CONTROLLERS :

A POWER BASED SYSTEM &OTHER STATIC EQUIPMENT

THAT PROVIDE CONTROL OF ONE OR MORE A.C TRANSMISSION

PARAMETERS

BASIC TYPES OF FACTS DEVICES:

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CONTROLLERS

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CONTROL SYSTEM OF STATCOM

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SSSC DYNAMIC RESPONSE

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15

0.5 1 1.5 2 2.5 3 3.5 4 4.5200

300

400

500

600

700

800

900

1000

1100

Time (s)

Power(MW)onlineL1

SSSC operation with and without POD

POD on

10-cycle fault


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S h u n t 5 0 0 k V , 1 0 0 M V A

S e r i e s 1 0 0 M V A , 1 0 % i n j e c t i o n

1 0 0 0 M W

< - - - - - -

I

I

V

1 9 7 M W

< - - - - - -

1 2 7 7 M W

- - - - - - >

5 0 0 M W

- - - - - - >

6 9 0 M W

- - - - - - >

6 8 7 M W - 2 7 M v a r

- - - - - - >

2 3 0 k V

5 0 0 k V

C o n t r o l o f P o w e r F l o w u s i n g a U n i f i e d P o w e r

7 9 6 M W 1 5 M v a r

9 5 M W5 0 0 M W

1 0 0 0 M W

5 8 9 M W5 8 7 M W - 2 7 M v a r 1 2 7 9 M W

8 9 9 M W 2 8 M v a r

N a tu r a l p o w e r f l o w s

( B y p a s s b r e a k e r c l o s e d )a r e s h o w n i n r e d n o te s .

P o w e r f l o w s w i t h U P F C

( P r e f = 6 8 7 M W , Q r e f= - 2 7 M v a r )

a r e s h o w n i n b l u e n o te s .

P h a

p o w e r g u i

?

i n f o

V d

V d q r e f

V P Q L i n e s

V P

M e a s

U P F C

U P F

M e a s

T r i pB y p a s

P Q r e f

V d q r e

m

A 1

B 1

C 1

A

B

C

U P F

U P F C

BC

b c

T r 2 : 8 0 0 M V A

2 3 0 k V / 5 0 0 k V

BC

b c

T r 1 : 1 0 0 0 M V A

2 3 0 k V / 5 0 0 k V

D o u b l e

U P F C

C o n t r o

- 0 .

Q r e f ( p u )

P r e f ( p u )

A

BC

P o w e r

P n o m =

A

BC

P o w e r P l a n t # 1

P n o m = 1 0 0 0 M W

L 3 _ 5 0 k m

L 2 _ 5 0 k m

L 1 _ 6 5 k m

d o u b l e c i r c u i t

[ P Q

[ V d

[ V d[ P Q

m

A

B

C

E q u i

5 0 0

1 5 0

B y p a s s

A

B

C

B _ U P F C

A

B

C

B 5

a b c B 4

A

B

C

B 3

A

B

C

B 2

a

bc

B 1

A c t i v e P

B 1 B 2 B

B C

2 0 0 M W

V p o s . s e q . B 1 B 2 B 3 B

Q B 1 B 2 B 3 B 4 B 5 ( M

P P r e f ( p u )

Q Q r e f ( p u )

V c o n v _ m a g ( p u )

V c o n v _ p h a s e ( d e g . )

P B 1 B 2 B 3 B 4 B 5 ( M W


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POWER CONTROL OF UPFC

VPQ LINES

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TECHNICAL BENFITE OF FACTS DEVICES

*

** Better Operation

***

APPLICATIONS OF FACTS

LIMITATIONS OF FACTS

FUTURE SCOPE OF FACTS

controller load flow

control.

voltage

stability

transient

stability

dynamic

stability

STATCOM * *** *

SSSC ** * ***

UPFC *** *** **

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CONCLUSIONPower systems are being operated closer

than ever to there operating limits with the increased burden on

the use of transmission system and the heightened requirements

on the quality of power delivered, the application of power

electronic based equipment, such as FACTS and custom power

is being increased.

The Various Facts such as SHUNT,SERIES

And combination of SHUNT & SERIES controllers is found to

be efficient in improving existing technology. The stability of

the system considerably increased, the control of voltage,

damping of oscillation and increase in power for the same line

are the advantages associated with the FACTS technology.

In our study among all the FACTS controllers

UPFC is the most superior to other controllers. SHUNT

controllers (STATCOM) are compensates only reactive power

i.e. maintains constant voltage profile in the system. Series

controllers (SSSC) reduce the impedance of the line and also

provide reactive power compensation. Where as UPFC provide

both active and reactive power compensation independently.

BIBLOGRAPHY1. N.G. Hingorani, L.Gyugyi Under standing facts concept and

technology of flexible AC transmission systems.

2. L.Gyugyi unified power flow concept for Flexible AC transmission

systems

3. Dr. R. sreeram Kumar Flexible AC transmission systems-an

introduction

4. A. Deepak devan (ATLANTA university) paper presentation.

5. Anjan havanur, U.K. Hambrade, Active and Reactive power

management in transmission system.

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power flow control with upsc

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