Urgent Opportunities for Transmission System Enhacement.ppt

Research Results in Transmission Line Research Results in Transmission Line

s-Domain Models, Power System s-Domain Models, Power System

Harmonics, Electromagnetic Transients, Harmonics, Electromagnetic Transients,

Switching Overvoltage Suppressing Switching Overvoltage Suppressing

Devices Devices

and FACTS Controlsand FACTS Controls

Research Results in Transmission Line Research Results in Transmission Line

s-Domain Models, Power System s-Domain Models, Power System

Harmonics, Electromagnetic Transients, Harmonics, Electromagnetic Transients,

Switching Overvoltage Suppressing Switching Overvoltage Suppressing

Devices Devices

and FACTS Controlsand FACTS Controls

Urgent Opportunities for Transmission System Enhacement

2

Modal AnalysisModal AnalysisModal AnalysisModal Analysis• Used worldwide and number of engineering Used worldwide and number of engineering

applications continuosly increasesapplications continuosly increases

• Helps determining the nature of problemsHelps determining the nature of problems in spite of in spite of the limitations associated with linearizationthe limitations associated with linearization

• Most effective locations for placing equipment or Most effective locations for placing equipment or controllers to improve system controllers to improve system performanceperformance

• Equipment or controller designEquipment or controller design

• Cost-effective solutions in several power systems Cost-effective solutions in several power systems areasareas

3

Modal AnalysisModal Analysis in Power Systems in Power SystemsModal AnalysisModal Analysis in Power Systems in Power Systems

• Modeling of ac networks using descriptor and s-Modeling of ac networks using descriptor and s-domain models (transmission linesdomain models (transmission lines with with distributed distributed and frequency dependent parameters)and frequency dependent parameters)

• Small signal stability (Small signal stability (electromechanical oscillations, electromechanical oscillations, voltage stability andvoltage stability and ssubsynchronous ubsynchronous rresonance)esonance)

• Harmonic Harmonic aanalysisnalysis and filter design and filter design

• Electromagnetic Electromagnetic ttransientsransients

4

Poles(Eigenvalues)

TF Zeros

Pole Location

System Model(Descriptor System or

S-Domain)

Mode-Shapes,Participation Factors,TF Residues & Other

Modal Sensitivities

Linear TimeResponse

FrequencyResponse

Root-Locus &Root-Contour Plots

Bifurcations;Stability

Boundaries

Filter orController

Design

Reduced OrderModel

(SISO & MIMO)

Dynamic Analysis of Linear(ized) SystemsDynamic Analysis of Linear(ized) SystemsDynamic Analysis of Linear(ized) SystemsDynamic Analysis of Linear(ized) Systems

5

ss-Domain Modeling-Domain Modelingss-Domain Modeling-Domain Modeling

• NNodal admittance matrix (odal admittance matrix (YYbusbus)) is built is built in the s- in the s-domaindomain

• Equations are written directly in the s-domainEquations are written directly in the s-domain sisimpler, efficient and accurate mpler, efficient and accurate model for distributed model for distributed parameter,parameter, frequency dependen frequency dependentt transmission lines transmission lines

• YYields lower dimension system matricesields lower dimension system matrices

• EfficientEfficient eigensolution eigensolution algorithms algorithms have been have been developeddeveloped

• Advances the state-of-the-art Advances the state-of-the-art in modal analysisin modal analysis

6

Electromagnetic Transient ResultsElectromagnetic Transient ResultsElectromagnetic Transient ResultsElectromagnetic Transient Results

Synthetic System for Switching Transient Synthetic System for Switching Transient StudiesStudies

Transmission Line(500 kV, 300 km)

0.06 mH

100F

1 H

550

7 H 1.4FTransmission Line Parameters:

Zu = 0.028 /km +s 0.862 mH/km

Yu = s 0.0138 F/km

100F

7 H

E sin(0t + )

VS

VR

7

Reduced Order ModelReduced Order Model for V for VRR(s) / V(s) / VSS(s)(s)Reduced Order ModelReduced Order Model for V for VRR(s) / V(s) / VSS(s)(s)

• VVRR = Receiving end voltage / V = Receiving end voltage / VS S = Sending end = Sending end voltagevoltage

0

5

10

15

20

25

0 500 1000 1500 2000 2500 3000

Frequency (Hz)

Vol

tag

e (p

u)

Complete Model

16th Order Model

8


Sine Input ( = 0o)

9


Cosine Input ( = 90o)

10


Voltage Source Phase Angle ( in degrees)

Maximum Overvoltages

11


Maximum Overvoltage Case ( 60o)

12

Harmonic ResultsHarmonic ResultsHarmonic ResultsHarmonic Results

0.24 MW0.21 MVAr

0.10 MW0.09 MVAr

8.49 F

22.48 F

0.90 MW0.79 MVAr

0.12 MW0.10 MVAr

0.13 MW0.11 MVAr16.86 F

0.86 MW0.76 MVAr

0.86 MW0.76 MVAr

0.23 MW0.20 MVAr

1.09 MW0.96 MVAr

1.20 MW0.11 MVAr

11.24 F

0.14 MW0.12 MVAr

1.00 MW0.88 MVAr

0.15 MW0.13 MVAr

0.02 MW0.02 MVAr

2.81 F0.14 MW

0.13 MVAr

8.49 F2.54 MW

2.23 MVAr

15.18 MW6.47 MVAr

Bus 01

Bus 50

138 kV

11.9 kV

Bus 10 11.9 kV

Bus 11

Bus 12

Bus 13

Bus 14

Bus 101

Bus 21

Bus 22

Bus 23

Bus 24

Bus 25

Bus 201

Bus 31

Bus 32

Bus 33

Bus 34

Bus 35

Bus 301

Bus 41

Bus 42

Bus 43

0.43 MW0.38 MVAr

Bus 26

480 V

480 V

480 V

Z=1.712+j 8.94

0.50 MVA( 0.05 + j 5.0 )%

2.60 MVA( 0.05 + j 5.0 )%

7.00 MVA( 0.05 + j 5.0 )%

15.00 MVA( 0.08 + j 8.0 )%

15.00 MVA( 0.08 + j 8.0 )%

Source 1

Source 2

Source 3

13

Harmonic ResultsHarmonic ResultsHarmonic ResultsHarmonic Results

Weighted Impedance Seen from Bus 13

0

0.2

0.4

0.6

0.8

1

1.2

0 150 300 450 600 750 900 1050 1200 1350 1500Frequency (Hz)

Impe

danc

e (p

u)

Original System

Proposed Solution

14

TransientTransient Overvoltage Overvoltage Suppress Suppressinging DeviceDevice


• Line energization (500 kV, 300 km)

• Receiving end is open

TOSD

LOA

D

15



Line Energization

-1000

-500

0

500

1000

1500

0 0.05 0.1 0.15 0.2 0.25Time (ms)

Rec

eivi

ng

En

d V

olt

age

(kV

) Phase a

Phase b

Phase c

16



Line Energization (Enlarged View of Time Axis)

-1000

-500

0

500

1000

1500

0 0.005 0.01 0.015 0.02 0.025 0.03Time (ms)

Rec

eiv

ing

En

d V

olt

age

(kV

)

Phase a

Phase b

Phase c

17



Line Energization with Device

-1000

-500

0

500

1000

1500

0 0.05 0.1 0.15 0.2 0.25Time (ms)

Rec

eivi

ng

En

d V

olt

age

(kV

) Phase a

Phase b

Phase c

18



Line Energization with Device (Enlarged View of Time Axis)

-1000

-500

0

500

1000

1500

0 0.005 0.01 0.015 0.02 0.025 0.03Time (ms)

Rec

eivi

ng

En

d V

olt

age

(kV

) Phase a

Phase b

Phase c

19

FACTS Control StrategiesFACTS Control StrategiesFACTS Control StrategiesFACTS Control Strategies

• TCSC used for:TCSC used for:

– Line Power SchedulingLine Power Scheduling

– System Oscillation Damping (Power Oscillation System Oscillation Damping (Power Oscillation Damping – POD Controller)Damping – POD Controller)

1

3

4

P12

2

1000 MW

TCSC

P24

P23

20

TCSC Control System DiagramTCSC Control System DiagramTCSC Control System DiagramTCSC Control System Diagram

+

Power System

x re f

PI Controller

TCSC Controls

P I (s )

P O D (s )

xcont

POD Controller

+

B 2-4

B P O D

+F 2 (s )

F 1 (s )

x inp

B P I

21

TCSC ControlsTCSC Controls (Detail) (Detail)TCSC ControlsTCSC Controls (Detail) (Detail)

Ki = 5, Kp = 0.5 in all cases

xcont = P2-4 for Constant Line Power Strategy

+

s

+

B2-4

Ki + Kp

BPOD +

xinp

SeriesSusceptance

1 + sTws Tw Kstab

1 + saT

1 + sT

n

POD Controller

PI Controller

LogicON/OFF

Protection

Parallel LineStatus

Bmax

Bmin

xref

xcont

Washout Lead-Lag Gain

BPI

Bmax

Bmin

Bmax = 5

Bmin = 2.5

= 0.1

22

TCSC at Fixed Impedance ModeTCSC at Fixed Impedance ModeTCSC at Fixed Impedance ModeTCSC at Fixed Impedance Mode

• Step disturbance Step disturbance PPMECMEC = 1 % = 1 %

• Dominant Mode Dominant Mode = +0.305 ±j 6.126= +0.305 ±j 6.126

-70

0

70

0. 5. 10. 15. 20. 25. 30.

Time (s)

P1-2

P2-3

P2-4

1

3

4

2

TCSC

P24

P23PMEC

P12

23

TCSC with POD ControllerTCSC with POD ControllerTCSC with POD ControllerTCSC with POD Controller

-0.004

0.000

0.004

0.008

0.012

0.016

0. 5. 10. 15. 20.

Time (s)

P1-2

P2-3

P2-4

Time (s)Time (s)

• PPMECMEC = 1 % = 1 % D Dominant Mode ominant Mode = = --0.0.890890 ±j ±j 55..822822

• Incremental steady-state powers are equally shared Incremental steady-state powers are equally shared between the two linesbetween the two lines

1

3

4

2

TCSC

P24

P23PMEC

P12

24

TCSC with POD and Constant Line Power TCSC with POD and Constant Line Power ControllersControllers

TCSC with POD and Constant Line Power TCSC with POD and Constant Line Power ControllersControllers

-0.004

0.000

0.004

0.008

0.012

0.016

0. 5. 10. 15. 20. 25. 30.

Time (s)

Brings the power flow in line 2-4 to the specified value

P1-2

P2-3

P2-4

• PPMECMEC = 1 % = 1 % Dominant ModeDominant Modess = = --0.0.889889 ±j ±j 55..771 and 771 and = = --0.0.123123

1

3

4

2

TCSC

P24

P23PMEC

P12

25

Transient Stability ResultsTransient Stability ResultsTransient Stability ResultsTransient Stability Results

• Non-linear simulation data:

– t = 0.5 s Short circuit in line 2-3

– t = 0.6 s Fault clearance by line tripping

– t = 0.6 s Rejection of one generation unit (200 MW)

1

3

4

P12

2

800 MW

TCSC

P24

P23 = 0

26

Line Outage Condition (Small Signal Stability Line Outage Condition (Small Signal Stability Results)Results)


Serious Control Problem

Dominant Mode: = 0

-0.04

-0.02

0.00

0.02

0.04

0. 5. 10. 15. 20.

Time (s)

PI-Controller = ON

POD Controller = ON

V2

V4

1-2

27



0.000

0.003

0.006

0.009

0.012

0.015

0. 5. 10. 15. 20. 25. 30.

Time (s)

PI-Controller = OFF

POD Controller = ON

System Stable

Dominant Mode: = -2.41 ±j 3.64

P1-2

P2-4

28


2.5

3.0

3.5

4.0

4.5

5.0

0. 2. 4. 6. 8. 10.

Time (s)

400

600

800

1000

0. 2. 4. 6. 8. 10.

Time (s)

PI-Controller = ONPOD Controller = ON

(TCSC output limiter is active – Bmin , Bmax)

System Very Poorly

Damped

P2-4BTCSC

Short circuit in line 2-3 ( t = 0.5 s )

Fault Clearance by line tripping and one generator unit drop ( t = 0.6 s )

29


2.5

3.0

3.5

4.0

4.5

5.0

0. 2. 4. 6. 8. 10.

Time (s)

400

600

800

1000

0. 2. 4. 6. 8. 10.

Time (s)

PI-Controller channel turned off by protection logics when line 2-3 is

tripped

System Highly Damped

P2-4

BTCSC

Short circuit in line 2-3 ( t = 0.5 s )

Fault Clearance by line tripping and one generator unit drop ( t = 0.6 s )

30

Emulating UPFC using TCSC + SVC Emulating UPFC using TCSC + SVC Emulating UPFC using TCSC + SVC Emulating UPFC using TCSC + SVC

• Using TCSC & SVC to emulate UPFC with functions:Using TCSC & SVC to emulate UPFC with functions:– Line Power SchedulingLine Power Scheduling– System Oscillation DampingSystem Oscillation Damping– Bus Voltage ControlBus Voltage Control

1

3

4

P12

2

1000 MW

SVC

TCSC

P24

P23

EmulatedUPFC

31

Emulating UPFC using TCSC + SVCEmulating UPFC using TCSC + SVCEmulating UPFC using TCSC + SVCEmulating UPFC using TCSC + SVC

1

3

4

2

TCSC

P24

P23PMEC

P12

SVC

EmulatedUPFC

-5.0E-3

0.0E+1

5.0E-3

1.0E-2

1.5E-2

0. 2. 4. 6. 8. 10. 12. 14. 16. 18. 20.

Time (s)

Line Active Power Flow

P1-2

P2-3

P2-4

Line Active Power Flow Deviations

Brings the power flow in line 2-4 back to the specified value

32

-2.0E-3

-1.0E-3

0.0E+1

1.0E-3

0. 2. 4. 6. 8. 10. 12. 14. 16. 18. 20.

Time (s)

With Voltage Control Without Voltage Control

Voltage Deviation at Bus 2

Emulating UPFC using TCSC + SVCEmulating UPFC using TCSC + SVCEmulating UPFC using TCSC + SVCEmulating UPFC using TCSC + SVC

Brings the voltage at bus 2 to the specified value

1

3

4

2

TCSC

P24

P23PMEC

P12

SVC

EmulatedUPFC

Without Voltage ControlWith Voltage Control

33

Propagation of Electromechanical Propagation of Electromechanical DisturbancesDisturbances


Input: Input: PPMECMEC at at ItaipuItaipu

Output: Output: along the along the systemsystem

1- Itaipu1- Itaipu

2- Emborcação2- Emborcação

3- Serra da 3- Serra da MesaMesa

4- Tucurui4- Tucurui

5- Xingó5- Xingó

1122

33

44

55

PPMECMEC

34



-3.5E-4

-1.8E-4

0.0E+1

1.7E-4

3.5E-4

0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Time (s)

- Itaipu- Itaipu

- Emborcação- Emborcação

- Serra da Mesa- Serra da Mesa

- Tucurui- Tucurui

- Xingó- Xingó

©© Unpublished material from Ph.D. thesis of Julio C. R. Ferraz Unpublished material from Ph.D. thesis of Julio C. R. Ferraz


Output: Output: along along the the systemsystem

35



-3.5E-4

-1.8E-4

0.0E+1

1.7E-4

3.5E-4

0. 0.2 0.5 0.7 0.9 1.1 1.4 1.6 1.8 2.1 2.3

Time (s)

- Itaipu- Itaipu

- Emborcação- Emborcação

- Serra da Mesa- Serra da Mesa

- Tucurui- Tucurui

- Xingó- Xingó

0.4 1.0 1.2 1.5 1.9

©© Unpublished material from Ph.D. thesis of Julio C. R. Ferraz Unpublished material from Ph.D. thesis of Julio C. R. Ferraz


Output: Output: along along thethe

systemsystem

36

Concluding RemarksConcluding RemarksConcluding RemarksConcluding Remarks

• Fernando França has given a broad view of the Fernando França has given a broad view of the challenges faced by the Brazilian ISOchallenges faced by the Brazilian ISO

• Luiz Pilloto presented developments on HSIL lines, Luiz Pilloto presented developments on HSIL lines, Defense Plans, FACTS concepts, new FACTS Defense Plans, FACTS concepts, new FACTS equipment and software toolsequipment and software tools

• This presentation covered a range of topics in which This presentation covered a range of topics in which the speaker is directly involvedthe speaker is directly involved

• Not much was said about Power Infrastructure Not much was said about Power Infrastructure Vulnerability, but the speaker is eager to contribute Vulnerability, but the speaker is eager to contribute to the discussionsto the discussions

Urgent Opportunities for Transmission System Enhacement.ppt

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