Final Project Content

7/25/2019 Final Project Content

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What is FACTS?

FACTS is defined as "a power electronic based system and other static equipment that provide

control of one or more AC transmission system parameters to enhance controllability and

increase power transfer capability.

In general, FACTS Controllers can be divided into four categories:

1. Series Controllers-

The series controller could be variable impedance, such as capacitor, reactor etc.,

or a power electronics based variable source of main frequency, subsynchronous

harmonic frequencies to serve the desired need. !n principle all series controllers

inect volta#e in series with the line.

2. Shunt Controllers-

The shunt controllers may be variable impedance, variable source, or a

combination of these. !n principle, all shunt controllers inect current in to the

systems at the point of connections.

3. Cobined series-series Controllers-

This could be a combination of separate series controllers, which are

controlled in a coordinated manner, in a multiline transmission system. These

controllers provide independent series reactive compensation for each line but

also transfer real power amon# the lines via the power lin$.

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!. Cobined series-shunt Controllers-

This could be the combination of separate shunt series controllers, which are

controlled in a coordinated manner. !n principle, combined shunt series

controllers inect current in to the system with the shunt part of the controller

volta#e in series in the line with the series part of the controllers.

"eed of co#ensation:-

To avoid transmission line con#estions thermal ratin# violation on transmission

networ$

%urpose of contin#ency analysis concern non compliance with reliability criteria.

For increased interconnection with nei#hborin# utilities, new overhead line circuit

planned

!f there is wide area volta#e control problem and the need for effective reactive power

compensation

Series co#ensation #rovides the follo$ing benefits:

&educes line volta#e drops

'imits load(dependent volta#e drops

!nfluences load flow in parallel transmission lines

!ncreases transfer capability

&educes transmission an#le

!ncreases system stability

Shunt co#ensation #erfors the follo$ing tas%s:

Stabili)e volta#e

Control dynamic reactive power

!mprove transient stability

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*amp active power oscillations

!ncrease power transfer capability

&ASIC T'ST S(ST'):This is five bus two #enerator system.This system is used ahead in modified form, to illustrate how the various FACTS

controllers perform in networ$ wide applications.

This power flow solution will be used as the base case a#ainst which all other

solutions will be compared.!n conventional power flow calculations, #enerators are set to #enerate a pre(

specified amount of active power, e+cept the slac$ #enerator which is left free, since it

has to #enerate sufficient active power to meet any shortfall in system#eneration. !t will

also #enerate or absorb any reactive power e+cess in the system.!n this e+ample the #enerator connected at the orth node is selected to be Slac$

-enerator, #eneratin# /.0 12 and 34.516Ar. The volta#e ma#nitude was $ept at

.47p.u and the volta#e phase an#le 44.The #enerator connected at the South node was set

to #enerate 8412 and the power flow solution indicates that it absorbs 7.93 16Ar to

$eep the nodal volta#e ma#nitude at specified value of p.u. The remainin# three nodes

contain no equipment to provide local reactive support and their nodal volta#e ma#nitude

drop below p.u. :owever, they $eep above 4.39p.u. 2hich is the minimum accepted

value by most electricity companies; So, the power networ$ does not seem to be in ris$

of under#oin# volta#e collapse at any point if an incremental load increase were to occur.!t should be noted that the ma+imum phase an#le difference between any pair of

adacent nodes is smaller than 94, which indicates that the power networ$ is not over

stretched in terms of active power flows. The lar#est active power flow ta$es place in the

transmission line connectin# the orth and South nodes< 53.//12 leaves the sendin#

end transmission line and 57.7812 reach the receivin# end. The lar#est transmission

active power loss also ta$es place in the transmission line, 0.8312. From the plannin#and operational point of view, this may be considered a #ood result. :owever, it should

be pointed out that no attempt was made to optimi)e the performance of the operation. !f

an optimi)ed solution is required where #enerator fuel cost and transmission power loss

are minimi)ed then an optimal power flow al#orithm =Ambri)(%ere), 335> would be

used as opposed to a conventional power flow al#orithm =Fuerte(?squivel, 33@>

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Test net$or% and #o$er flo$ result for base

"odal co#le* voltages of original net$or%:

+oltage

inforation

"orth South a%e )ain 'l

+#.u./ 1.0 1 0.4 0.! 0.42

5degrees/ 0 -2.0 -!.! -!. -6.44

7en

erator

#araeters:

"ode 87)9/ in)+Ar/ a*)+Ar/ +#.u./

South !0 -300 300 1

"et$or% connectivit; #.u./ .u./

"orth South 0.02 0.0 0.0

"orth a%e 0.0 0.2! 0.06

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South a%e 0.0 0.1 0.0!

South )ain 0.0 0.1 0.0!

South 'l 0.0! 0.12 0.03

a%e )ain 0.01 0.03 0.02

)ain 'l 0.0 0.2! 0.06

oad #araeters:

"ode 8load)9/ load)+Ar/

South 20 10

a%e !6 16

)ain !0 6'l 0 10

8o$er flo$ in basic s;ste:

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Static +ar Co#ensatorS+C/:-

*escription. it is a controlled node where volta#e ma#nitude

and the nodal active and reactive powers are specified while the S6CDs variable susceptance BS6C

is handled as a state variable. !f BS6C is within limits the specified volta#e is attend and

controlled node remains %6B type. :owever if B S6C #oes out of limit, BS6C is fi+ed at violated

limits and the node becomes % type in the absence of any other re#ulatin# equipments

connected to the node and capable of achievin# volta#e control.

The active and reactive powers drawn by a variable shunt compensator connected

at node El are< %l4 , l(G6lG0BS6C

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S+C at bus )ain:

S6C at 'AH?

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S+C at "orth:

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S+C at South:

S+C at '):

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?bserved =esults:

Conclusion:

Above table shows the five cases where S6C is connected to different buses so the active power

flow chan#es with respect to position of S6C.when S6C is at bus 'AH? the followin#

conclusion we can see.The power flow result indicates that the S6C #enerates 04.9 16Ar in

order to $eep the volta#e ma#nitude at p.u. volta#e ma#nitude at 'a$e ode. The S6C

installation results in an improved networ$ volta#e profile e+cept in ?'1, which is too far away

from 'a$e ode to benefit from the S6C influence. The Slac$ #enerator reduces its reactive

power #eneration by almost 7I compared to the base case and the reactive power e+ported from

orth to 'a$e reduces by more than /4I. The lar#est reactive power flow ta$es place in the

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transmission line connectin# orth and South, where @8. 16Ar leaves orth and @8 16Ar

arrives at south. !n #eneral, more reactive power is available in the networ$ than in the base case

and the #enerator connected at south increases .its share of reactive power absorption compared

to the base case. As e+pected, active power flows are only mar#inally affected by the S6C

installation. the best location to insert S6C is at bus ?'1 as at that bus active power flow

increased and reactive power flow is decreased.

Th;ristor Controlled Series Co#ensation TCSC/:-

!t is possible to control the current and thus the load flow in parallel transmission lines, which

simultaneously improves system stability. %ower oscillation dampin# and miti#ation of sub(

synchronous resonance can be reali)ed.

@escri#tion:

Series capacitors installations can also be controlled by thyristors. The Thyrister

Controlled Series Compensation =TCSC> offers several advanta#es over conventional

fi+ed series capacitor installations.

Th;ristor Controlled Series Co#ensation TCSC:-

These advanta#es include

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