Voltage Stabilization With Shunt Reactors

(1)

V

oltage stabilization

in transmission grids

with fixed

and variable shunt reactors

AB

(2)

Month DD, YYYY | Slide 2 Month DD, YYYY | Slide 2

ABB Red T

ie event, 6/4/2013.

Agenda

Re

Reactive power compactive power comp ensaensatiotion, Wn, Why shhy shunt runt r eaeactoctors?rs? Re

Reliable Dliable Design oesign of shf shunt unt reareactoctorsrs



 General designGeneral design



 Sound and VibrationsSound and Vibrations



 Variable shunt reactor (VSR)Variable shunt reactor (VSR)



 TestingTesting

T

Transmisransmis sion sion aapplpplicationications wits with VSh VSRR References and summary

(3)

Month DD, YYYY | Slide 2 Month DD, YYYY | Slide 2

ABB Red T

ie event, 6/4/2013.

Agenda

Re

Reactive power compactive power comp ensaensatiotion, Wn, Why shhy shunt runt r eaeactoctors?rs? Re

Reliable Dliable Design oesign of shf shunt unt reareactoctorsrs



 General designGeneral design



 Sound and VibrationsSound and Vibrations



 Variable shunt reactor (VSR)Variable shunt reactor (VSR)



 TestingTesting

T

Transmisransmis sion sion aapplpplicationications wits with VSh VSRR References and summary

(4)

Reactive power compensation,

Why shunt reactors?

AB

(5)

Month DD, YYYY | Slide 4

Apparent power consists of active(true) and reactive power components

P = S*cos 

Q = S*sin 

Reactive power compensation

Definitions

(6)

Active (True) power

Voltage and current in phase, cos = 1

Reactive power compensation

Definitions

(7)

Reactive power

Voltage and current out of phase 90 deg, cos = 0ind

Inductive circuit, we say that the current

lags

the voltage.

Capacitive circuit, we say that the current

leads

the voltage.

Reactive power compensation

Definitions

(8)

To run a marathon with your hands in your

pockets is very tiresome

The swinging movement of your body

has to be compensated with your arms.

This arm movement could be called a reactive power

needed to help you move

forward and also to keep the body balance

Likewise in an electrical power system the

reactive power in balance is the carrier of the

true power.

If the reactive power is consumed the voltage

decreases, its ability to transport the true

power decreases.

Reactive power compensation

Definitions

(9)

Reactive power compensation

Voltage control

(10)

Reactive power compensation

Voltage control

(11)

Transmission planning in North America

The ISO/RTO Council (IRC) is comprised of 10

Independent System Operators (ISOs) and Regional Transmission Organizations (RTOs) in North America. These ISOs and RTOs serve two-thirds of electricity

consumers in the United States and more than 50 percent of Canada's population

(12)

Reactive power compensation

Voltage control

(13)

Reactive power compensation

Voltage control

(14)

1.

Stability on long line transmissions

2.

Voltage control during light load

conditions

Reactor restores voltage to specified value

Voltage increase from capacitive generation X X 1 U X Q Q Q Q X

(15)

AC power cable is never loaded

with its natural load

(losses, heating and cooling)

Always more reactive power is

produced than what is absorbed

Need for shunt reactors.

(16)

Reactive power compensation

Voltage control

(17)

Reactive power compensation

Voltage control

(18)

Z

_c

= sqrt( l/c)

Surge impedance

P

_SIL

= V

₀2

_{/ Z}

c

Natural load at transmission voltage V

0

At P

_SIL

•Insulation is uniformly stressed at all points along line

•Power factor is unity, cos



= 1

•The ”natural” reactive power is zero

Reactive power compensation

Voltage control

(19)

Reactive power compensation

Voltage control

(20)

Reactive power compensation

Voltage control

(21)

Reactive power compensation

Voltage control

(22)

-The shu nt reactor A volt age

regulating device

Electrical power system

Transmission line at no load condition, I2=0

V1 V2

I1 _I2

V1 = Vr cos

Vr

At 200 miles, electrical length

 at 60 Hz is 23,2 degrees



(at 50 Hz is 19,3 degrees)

V2 will be 1,088 pu (1,06 pu)

I1 = 0,429 pu !!!

Q1 = 0,429 P

_SIL

(23)

Reactive power compensation

Voltage control

(24)

-The shu nt reactor A volt age

regulating device

Electrical power system

V1 V2

I1 _I2

Transmission line at no load condition and X chosen so that V2 = V1

At 60 Hz

Midpoint voltage = V1/cos (/2)= 1,021 pu I1= I2= Q1 = Q2 = 0,2055 P_SIL

Required rating of shunt reactor

At 500 kV voltage system, Z_SIL= 250 ohm

Q2 =

(25)

Reactive power compensation

Voltage control

(26)

Degree of shunt compensation

Z

_c

´

= Z

_c

/ sqrt( 1-k

_sh

) ; k

_sh

positive, inductive compensation

Shunt reactors

- increase virtual surge impedance Z

_c

´

- reduce virtual natural load P

_SIL

´

100 % inductive shunt compensation, k

_sh

=1

- reduces P

_SIL

´

to zero

- increases Zc

´

to ∞

implies a flat voltage profile at zero load.

Reactive power compensation

Voltage control

(27)

P

₂

, Q

₂

U

₂

U

₁

(R) + X

Q

At natural loading, SIL; P

₂

= P

_SIL

(

reactive power balance

₎

U

₁

U

₂

1,0 pu

Application of shunt reactors

Voltage profile

(28)

P

₂

, Q

₂

U

₂

U

₁

(R) + X

Q

At no or low load (P

₂

), voltage profile, ”Ferranti effect”

U

₁

U

₂

1,0 pu

Application of shunt reactors

Voltage profile

(29)

P

₂

, Q

₂

U

₂

U

₁

(R) + X

Q

At no or low load (P

₂

), voltage profile with connected SR

U

₁

U

₂

1,0 pu

Application of shunt reactors

Voltage profile

(30)

P

₂

, Q

₂

U

₂

U

₁

(R) + X

Q

Increased load (P

₂

), voltage profile with connected SR

U

₁

U

₂

1,0 pu

Application of shunt reactors

Voltage profile

(31)

P

₂

, Q

₂

U

₂

U

₁

(R) + X

Q

Increased load (P

₂

), voltage profile with connected VSR

U

₁

U

₂

1,0 pu

Reactor power less than rated power.

VSR = Variable Shunt Reactor

Application of shunt reactors

(32)

ABB Reactors (

oil immersed

), Types and usage

Shunt reactors

(33)

Reliable Design of shunt reactors

(34)

Rigid gapped core limb for lo w soun d level 1. Non-flexible grain oriented steel core sheet 2. Bounded with well proven stiff steatite spacers 3. Spacers are machined to exactly the same height Precisi on crafted process ensures:

 Small axial movements  Low vibrations & sound

Design

(35)

Earthed shield

no stress concentration towards core or winding Winding centre entry and ground potential towards yokes reduces overall size and losses

Neutral

HV line terminal

Design

(36)

It should

withstand the load

of 40 cars, applied

120 times per

second for 30

years continuous

without rattling

and high noise

Design

(37)

Options for sound reduction

– Typical sound levels

Internal noise control on ly:

Sound power level 80 – 95 dB(A) Sound pressure level 65 – 75

dB(A)

With s ound panels:

dB(A)

With so und enclosur e:

(38)

Overvoltage Operating voltages

Voltage Current

Application of shunt reactors

Linearity

(39)

Variable Shunt Reactor (VSR)

(40)

June 10, 2013 | Slide 39

Variable shunt reactor applications

To foresee the future?

 We cannot today foresee the grid conditions

of the future

 Generation and load patterns  Interconnections

 Regulations

 Need for reactive power compensation  Trend towards controllability, flexibility and

intelligence of the networks

 The expected life time of a reactor is 30-40

years

 This talks to the favor of variable shunt

(41)

Neutral Phase terminal Neutral Phase terminal

OLTC An unconventional

Reactor built on

conventional technology

Design sol utions taken from our way of bui lding Shunt Reactors and Power Transfor mers

(42)

Normal shunt reactor Regulated shunt reactor

(43)

Feasible regulatio n r atio, R, versus operation voltage

(44)

On-load tap changer ABB

Three-phase neutral point tap changer of the diverter switch type

With conventional or vacuum current interrupters

(45)

Control of LTC of a VSR



Manual / Remote control



Automatic relay control



Control parameters, voltage and Mvar

(46)

Testing

(47)

 Winding resistance  Applied voltage test

 Inductance and loss m easurement  Zero-sequence impedance

 Accessories and small wiring  Switching impulse test

 Lightning impulse test  PD-measurement

 Audib le no ise test an d v ibratio ns  Test of temperature ris e

 Measurement of harmonics  Inductance curve measurement  Insulation resistance measurement

 Capacitance and power factor in insulation

Design

(48)

G C C

T1 T2

R

Design

(49)

Transmission applications with VSR

(50)

Variable Shunt Reactors (VSR) benefits

Statnett Norway

•Reduced voltage jump at switching on operation.

•Coarse tuning of SVC equipment for best dynamical operation. •Reduction of number of breakers. No parallell fixed reactors. •Adjusting of seasonal related loads.

•Adjusting of daily dependable loads. •Flexible spare unit possibility.

•Flexibility for new load conditions in the network. At revisions for example. •Flexibility to move reactor to other locations.

(51)

Variable Shunt Reactors (VSR)

420 kV

(52)



High voltage level situation in the state, especially in the

north.



Surplus of reactive power .



Therefore big need for inductive power compensation.



VSR solution gives flexible voltage control.

Dominion (VA)

(53)

Dominion (VA)

A,Substation Carson. B,Substation Garrysonville. C,Substation Yadkin. D,Substation Hamilton. E,Substation Jefferson street. F,Substation Idylwood. Voltage stabilisation, Virginia state. VSR 50-100 Mvar, 242 kV, 7 units.

Variable shunt reactor applications

B D

F

C E

(54)

X

Reactor placed on the high-voltage side

• Reactor power compensation from generators not longer reliable • Minimize number of breaker operations

• Extended use of cables put higher demand on reactive power compensation • Eliminating air core reactors on transformer tertiary

• Air core reactors take place and are spreading magnetic field • Tap changer used to keep voltage at constant value

Variable Shunt Reactor to Dominion, Virginia USA.

(55)

June 10, 2013013 | Slide | Slide 5454

Variable Shunt Reactor

50-100 Mvar, 242 kV

(56)

Variable Shunt Reactor

Equipped with sound Equipped with sound housing for sound level housing for sound level environmental impact. environmental impact.

50-100 Mvar, 242 kV.

(57)

Cas

e, Wi

nd

Pow

er ge

ner

ati

on in T

exa

s

Sharyland Sharyland Utilities Utilities part of CREZ part of CREZ Wind Wind energy energy transmission transmission to consumer to consumer centres in centres in ea eastern stern TXTX

(58)

June 10, 2013 | Slide 57

Wind Power Generation in Texas

Sharyland Utilities part of CREZ

(59)

Wind Power generation in Texas

Final stage

(60)

Variable shunt reactor applications

Sharyland Utilities

ABB in tank tap changer VUCG for variable Mvar output.

(61)

Variable shunt reactor applications

Sharyland Utilities

Reactive power compensation flexibility for better voltage control.

More cost effective customer solution to two or more reactors with fixed ratings. Smaller footprint.

Less number of breakers and breaker maintenance. Customer chooses ABB VSR for the reliability.

(62)

Zero Miss Phenomena

(and other VSR application)

Siphon transmission line, 400 kV

Cable transmission

line from wind mill park, 235 kV

1. Askaer S/S, 50-110 Mvar, 2 units to avoid zero miss phenomena. TC in min Mvar position when cable is energized. 2. Tjele S/S, 70-140 Mvar, to minimise

voltage jump min Mvar position when switched in.

3. Revsing S/S,70-140 Mvar, to minimise voltage jump min Mvar position when switched in.

4. Grenaa S/S, 120 Mvar, compensation of sea cable from wind mill park.

5. Trige S/S, 60 -120 Mvar, 2 units to compensate for variable wind power generation and loss optimisation. 1

2

3

4 5

(63)

ABB VSR World wide references

Customer Nominal voltage (kV)

Rating range, 3 phase (Mvar)

Type Year of delivery

Ghana, Africa 161 9_‐18 OLTC 4 units 1989 1 unit 2001 GEW Cologne,

Germany

110 10_‐30 DETC 1 unit 1996

Channel Islands, UK 132 7‐16 OLTC 2 unit 1999

Sonabel, Burkina Faso, Africa

225 13‐30 OLTC 1 unit 2004

Statnett, Norway 420 120‐200 OLTC 1 unit 2008 Statnett, Norway 420 120‐200 OLTC 2 units 2010 Statnett, Norway 300 80_‐150 OLTC 2 units 2010 E‐Co Vannkraft, Norway 420 120‐200 OLTC 1 unit 2010 Dominion Virginia, USA 242 50_‐100 OLTC 3 units 2009 4 units 2010 1 unit 2014 Svenska Kraftnät, Sweden 400 110‐180 OLTC 1 unit 2010 Energinet dk, Denmark 235 60_‐120 OLTC 2 units 2011

Statnett, Norway 420 90_‐200 OLTC 8 units 2012/2013 1 unit 2014 Sharyland Utilities TX, USA 345 50‐100 OLTC 1 unit 2013 Energinet dk, Denmark 400 50‐110 70_‐140 OLTC 3 units 2013/2014 2 units 2013/2014 Center Point Energy

TX, USA

(64)

References

(65)

ABB Shunt reactors

References

170 Mvar, 525 kV

to APS, Arizona

(66)

150 Mvar, 345 kV

to New York Power Authority

Equipped with a sound

enclosure for very low sound

emission ~ 55 dB

ABB Shunt reactors

References

(67)

ABB Shunt reactors

References

80 Mvar, 230 kV

to PEPCO

(68)

Summary

• AC apparent power (MVA) has two components, Active power (MW) and Reactive power (Mvar).

• Voltage is influenced by the level of Reactive power (AC system). • The Shunt Reactor is a regulating device to limit the voltage.

• High manufacturing accuracy is requested to make reliable shunt reactors. • The Variable Shunt Reactor (VSR) principle is to regulate number of

electrical turns by a tap changer.

• VSR is used by customers to satisfy the demand for improved flexibility (economy driven) in the grid.