Voltage Stabilization With Shunt Reactors

 AB B Tran sf or mer s, Tom as Ol ss on , Syr acu se (NY), 6/4/2013

Voltage stabilization in transmission grids with fixed and variable shunt reactors

 ABB Red Tie Tie event, 6/4/2013.  Agenda Reactive Reactive power comp ensatio ensation, n, Why Why sh unt r eacto eactors? rs? Reliable Reliable Design Design of o f sh unt reacto reactors rs    

General design Sound and Vibrations Variable shunt reactor (VSR) Testing

Transmis sion application ppl ications s with wit h VSR VSR References and summary

© ABB Month DD, YYYY | Slide 2

 ABB Red Tie Tie event, 6/4/2013.  Agenda Reactive Reactive power comp ensatio ensation, n, Why Why sh unt r eacto eactors? rs? Reliable Reliable Design Design of o f sh unt reacto reactors rs    

General design Sound and Vibrations Variable shunt reactor (VSR) Testing

Transmis sion application ppl ications s with wit h VSR VSR References and summary

© ABB Month DD, YYYY | Slide 2

 ABB  AB B Transf Tran sfor ormer mers, s, Tomas Ols Olsso son, n, Syrac Sy racus use e (NY), 6/4/2013 6/4/2013

Reactive power compensation, Why shunt reactors?

Reactive power compensation Definitions Apparent power consists of active(true) and reactive power components

P = S*cos  Q = S*sin 

© ABB Month DD, YYYY | Slide 4

Reactive power compensation Definitions Voltage and current in phase, cos = 1

Active (True) power 

© ABB Month DD, YYYY | Slide 5

Reactive power compensation Definitions Voltage and current out of phase 90 deg, cos = 0ind 

Reactive power 

Inductive circuit, we say that the current lags the voltage. Capacitive circuit, we say that the current leads the voltage.

© ABB Month DD, YYYY | Slide 6

Reactive power compensation Definitions 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

© ABB Month DD, YYYY | Slide 7

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 Voltage control

© ABB Month DD, YYYY | Slide 8

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 9

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

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 11

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 12

 Application of shunt reactors 1. Stability on long line transmissions 2. Voltage control during light load

conditions X Q Q

Q U

X Voltage increase from capacitive generation

X Q

Reactor restores voltage to specified value

1 X

© ABB Month DD, YYYY | Slide 13

Reactive Power Generation in cables  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.

© ABB Month DD, YYYY | Slide 14

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 15

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 16

Reactive power compensation Voltage control Zc = sqrt( l/c) PSIL = V02 / Zc

Surge impedance Natural load at transmission voltage V0

 At PSIL •Insulation is uniformly stressed at all points along line •Power factor is unity, cos  = 1 •The ”natural” reactive power is zero

© ABB Month DD, YYYY | Slide 17

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 18

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 19

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 20

The shu nt reactor   A volt age regulating device

Electrical power system Transmission line at no load condition, I2=0

V1

Vr 

V2

V1 = Vr cos At 200 miles, electrical length  at 60 Hz is 23,2 degrees  (at 50 Hz is 19,3 degrees)

I1

     1    2     s   r   e   m   r   o    f   s   n   a   r    T    A    B    B    B    A    ©

V2 will be 1,088 pu (1,06 pu) I2

I1 = 0,429 pu !!! Q1 = 0,429 PSIL There is a line charging current in the sending end generators

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 22

The shu nt reactor   A volt age regulating device

Electrical power system 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 V1

V2

Q2 =      3    2     s   r   e   m   r   o    f   s   n   a   r    T    A    B    B    B    A    ©

= 205 Mvar (3 phase) I1

I2

Reactive power compensation Voltage control

© ABB Month DD, YYYY | Slide 24

Reactive power compensation Voltage control Degree of shunt compensation Zc´ = Zc / sqrt( 1-ksh) ; ksh positive, inductive compensation Shunt reactors

- increase virtual surge impedance Zc´ - reduce virtual natural load PSIL´

100 % inductive shunt compensation, ksh =1 - reduces PSIL´to zero - increases Zc´to ∞ implies a flat voltage profile at zero load.

© ABB Month DD, YYYY | Slide 25

 Application of shunt reactors Voltage profile (R) + X

U1

P2, Q2 U2

Q

 At natural loading, SIL; P2 = PSIL ( reactive power balance) 1,0 pu

U1

U2

 Application of shunt reactors Voltage profile (R) + X

U1

P2, Q2 U2

Q

 At no or low load (P2), voltage profile, ”Ferranti effect” 1,0 pu

U1

U2

 Application of shunt reactors Voltage profile (R) + X

U1

P2, Q2 U2

Q

 At no or low load (P2), voltage profile with connected SR 1,0 pu

U1

U2

 Application of shunt reactors Voltage profile (R) + X

U1

P2, Q2 U2

Q

Increased load (P2), voltage profile with connected SR 1,0 pu

U1

U2

 Application of shunt reactors Fine tuning of the voltage with a variable shunt reactor  (R) + X

U1

P2, Q2 U2

Q

Reactor power less than rated power.

Increased load (P2), voltage profile with connected VSR 1,0 pu

U1

VSR = Variable Shunt Reactor 

U2

 ABB Reactors (oil immersed), Types and usage Shunt reactors Voltage control

 ABB Transformers, Tomas Olsson, Syracuse (NY), 6/4/2013

Reliable Design of shunt reactors

Design Low sound

Rigid gapped core limb for lo w soun d level 1. 2. 3.

Non-flexible grain oriented steel core sheet Bounded with well proven stiff steatite spacers Spacers are machined to exactly the same height

Precisi on crafted process ensures:  

Small axial movements Low vibrations & sound

Design Winding arrangement Neutral HV line terminal

Winding centre entry and ground potential towards yokes reduces overall size and losses

Earthed shield no stress concentration towards core or winding

Design Why to be careful when buying a reactor?

It should withstand the load of 40 cars, applied 120 times per second for 30 years continuous without rattling and high noise

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: Sound power level 70 – 85 dB(A) Sound pressure level 55 – 65 dB(A)

With so und enclosur e: Sound power level 65 – 80 dB(A) Sound pressure level 50 – 60 dB(A)

 Application of shunt reactors Linearity Operating voltages

Overvoltage Voltage Current

 ABB Transformers, Tomas Olsson, Syracuse (NY), 6/4/2013

Variable Shunt Reactor (VSR)

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 reactors

© ABB Group June 10, 2013 | Slide 39

VSR winding concept Neutral Neutral

Phase Phase terminal 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

VSR design concept

Normal shunt reactor

Regulated shunt reactor  

VSR feasible Mvar output ranges

Feasible regulatio n r atio, R, versus operation voltage

VSR On-load tap changer ABB Three-phase neutral point tap changer of the diverter switch type With conventional or vacuum current interrupters

Control of LTC of a VSR



Manual / Remote control

 Automatic relay control Control parameters, voltage and Mvar 



© ABB Group June 10, 2013 | Slide 44

 AB B Tran sf or mer s, Tom as Ols so n, Sy rac us e (NY), 6/4/2013

Testing

Design Full scale test              

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 Full scale test T1

G

C

T2 C

R

 AB B Tran sf or mer s, Tom as Ols so n, Sy rac us e (NY), 6/4/2013

Transmission applications with VSR

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.

Variable Shunt Reactors (VSR)

420 kV 120-200

Dominion (VA) Variable shunt reactor applications 

  

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) Variable shunt reactor applications  A, Substation

Carson. B, Substation Garrysonville. C, Substation Yadkin. D, Substation Hamilton. E, Substation Jefferson street. F, Substation Idylwood.

D E

F B

Voltage stabilisation, Virginia state.

VSR 50-100 Mvar, 242 kV, 7 units.

© ABB Group June 10, 2013 | Slide 52

C

Variable Shunt Reactor to Dominion, Virginia USA. EHV

Reactor placed on the high-voltage side

EHV

Q

Q

X NEW

X OLD

• 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 © ABB Group June 10, 2013 | Slide 53

Variable Shunt Reactor  50-100 Mvar, 242 kV

© ABB Group June 10, 2013 2013 | Slide 54

Variable Shunt Reactor  50-100 Mvar, 242 kV. Equipped with sound housing for sound level environmental impact.

© ABB Group June 10, 2013 2013 | Slide 55 55

Case, Cas e, Wind Wind Pow Power er gener generati ation on in Texa Texass

Sharyland Utilities part of CREZ

Wind energy transmission to consumer centres in eastern eastern TX

Wind Power Generation in Texas Sharyland Utilities part of CREZ

© ABB Inc. June 10, 2013 | Slide 57

Wind Power generation in Texas Final stage

Flexibility use for transmission line expansion and voltage stability

Variable shunt reactor applications Sharyland Utilities

 ABB in tank tap changer VUCG for variable Mvar output.

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.

50-100 Mvar/345 kV

Zero Miss Phenomena (and other VSR application)

1.

2. Cable transmission line from wind mill park, 235 kV 3. Siphon transmission line, 400 kV

2

4 5

4. 5.

1 3

Askaer S/S, 50-110 Mvar, 2 units to avoid zero miss phenomena. TC in min Mvar position when cable is energized. Tjele S/S, 70-140 Mvar, to minimise voltage jump min Mvar position when switched in. Revsing S/S,70-140 Mvar, to minimise voltage jump min Mvar position when switched in. Grenaa S/S, 120 Mvar, compensation of sea cable from wind mill park. Trige S/S, 60 -120 Mvar, 2 units to compensate for variable wind power generation and loss optimisation.

 ABB VSR World wide references Customer

Ghana, Africa

Nominal voltage

Rating range, 3

(kV)

phase (Mvar)

161

9‐18

Type

Year of delivery

OLTC

4 units 1989 1 unit 2001

GEW Cologne,

110

10‐30

DETC

1 unit 1996

Channel Islands, UK

132

7‐16

OLTC

2 unit 1999

Sonabel, Burkina

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,

420

120‐200

OLTC

1 unit 2010

242

50‐100

OLTC

Germany

Faso, Africa

Norway Dominion Virginia, USA

3 units 2009 4 units 2010 1 unit 2014

Svenska Kraftnät,

400

110‐180

OLTC

1 unit 2010

235

60‐120

OLTC

2 units 2011

420

90‐200

OLTC

8 units 2012/2013

Sweden Energinet dk, Denmark Statnett, Norway

1 unit 2014 Sharyland Utilities TX,

345

50‐100

OLTC

400

50‐110

OLTC

1 unit 2013

USA Energinet dk, Denmark Center Point Energy TX, USA

70‐140 143

25‐50

3 units 2013/2014 2 units 2013/2014

OLTC

1 unit 2014

 AB B Tran sf or mer s, Tom as Ols so n, Sy rac us e (NY), 6/4/2013

References

 ABB Shunt reactors References

170 Mvar, 525 kV to APS, Arizona

 ABB Shunt reactors References

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

80 Mvar, 230 kV to PEPCO equipped with sound panels

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.