hector latorre, abb facts, 201611- -24 tcsc introduction ... · tcsc introduction and its...

© ABB Group November 28, 2016 | Slide 1

TCSC Introduction and its capability on SSR Mitigation

Hector Latorre, ABB FACTS, 2016-11-24


500 kV TCSC


TCSC Single Line Diagram

Capacitor Bank

MOV

Thyristorvalve

Reactor

Bypassswitch

Bypassswitch

Bypassdisconnector

Seriesdisconnector

TCSCOperational objectives

Thyristor Controlled Series Compensations (TCSC)

Subsynchronous resonance (SSR) mitigation,

Power oscillation damping,

Transient stability

Current (power flow) control,

Voltage control (reactance control),

Phase balancing control


TCSCMain components

Capacitor bank:compensation degree given by the customer

MOV:study performed as a FSC

Reactor:determined by the factor 𝜆𝜆

𝜆𝜆 = 𝜔𝜔0𝜔𝜔𝑁𝑁

𝜆𝜆 = 𝑋𝑋𝐶𝐶𝑋𝑋𝐿𝐿

𝜆𝜆 can be between 2 and 4. Typical values: 2.5 and 3.5

Thyristor valves:Number of thyrstors is mainly a function of the capacitorvoltage at triggering instant and protective level


TCSCSteady state operation

Currents in TCSC circuit

𝑖𝑖𝑉𝑉 = 𝑖𝑖𝐿𝐿−𝑗𝑗𝑋𝑋𝐶𝐶

𝑗𝑗 𝑋𝑋𝐿𝐿 − 𝑋𝑋𝐶𝐶

𝑖𝑖𝐶𝐶 = 𝑖𝑖𝐿𝐿−𝑗𝑗𝑋𝑋𝐿𝐿

𝑗𝑗 𝑋𝑋𝐿𝐿 − 𝑋𝑋𝐶𝐶


iCiL

iV

iLXC

XL


TCSC OperationBlocked mode

1.004 1.006 1.008 1.01 1.012 1.014 1.016-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Time [s]

Lin

e cu

rren

t [pu

] C

apac

itor

curr

ent [

pu]

Cap

acito

r vo

ltage

[pu]


TCSC OperationCapacitive (boost or Vernier) mode

-50 0 50 100 150 200 250

-1

-0.5

0

0.5

1

-50 0 50 100 150 200 250-2

-1

0

1

2

-50 0 50 100 150 200 250-2

-1

0

1

2

deg

α

β

α−π/2 IL

UC

IV

𝑖𝑖𝐿𝐿

𝑢𝑢𝐶𝐶

𝑖𝑖𝑉𝑉


TCSC OperationCapacitive (boost or Vernier) mode

1.004 1.006 1.008 1.01 1.012 1.014 1.016-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Time [s]

Lin

e cu

rren

t [pu

] V

alve

cur

rent

[pu]

Cap

acito

r cu

rren

t [pu

] C

apac

itor

volta

ge [p

u]

𝑘𝑘𝐵𝐵 =�𝑈𝑈𝐶𝐶𝐶�𝑈𝑈𝐶𝐶𝐶

Boost factor:

𝑘𝑘𝐵𝐵 =𝑋𝑋𝑎𝑎𝑎𝑎𝑎𝑎𝑋𝑋𝐶𝐶𝐶


Operation in CAP mode

-200 0 200-2

-1

0

1

2

deg

uCbeta= 20.0 deg

-200 0 200-3

-2

-1

0

1

2

3

deg

iL, i

V

-200 0 200-2

-1

0

1

2

deguC

beta= 25.0 deg

-200 0 200-3

-2

-1

0

1

2

3

deg

iL, i

V-200 0 200

-2

-1

0

1

2

deg

uC

beta= 30.0 deg

-200 0 200-3

-2

-1

0

1

2

3

deg

iL, i

V


Steady state relation between firing angle and kB

0 10 20 30 40 50 60 70 80 90-3

-2

-1

0

1

2

3

4

beta (deg)

KBBoost factor vs. control angle, lambda=2.5


Typical operating range for POD


Typical operating range for SSR mitigation

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-0.5

0

0.5

1

1.5

2

2.5

3

3.5

Line current [pu]

Boo

st fa

ctor

kB

CAP-mode: Continuous operationCAP-mode: 30 min overloadCAP-mode: 10 sec overloadBP-mode: Continuous operationBP-mode: 30 min overloadBP-mode: 10 sec overload


TCSC ControlSynchronous Voltage Reversal

-50 0 50 100 150 200 250

-1

-0.5

0

0.5

1

-50 0 50 100 150 200 250-2

-1

0

1

2

-50 0 50 100 150 200 250-2

-1

0

1

2

deg

α

β

α−π/2 IL

UC

IV

𝑖𝑖𝐿𝐿

𝑢𝑢𝐶𝐶

𝑖𝑖𝑉𝑉

1.818 1.819 1.82 1.821 1.822 1.823 1.824 1.825 1.826 1.827 1.828-1

0

1

2

3

4

5

6

Lin

e cu

rren

t [kA

]

1.818 1.819 1.82 1.821 1.822 1.823 1.824 1.825 1.826 1.827 1.828-50

0

50

Cap

vol

tage

[kV

]

1.818 1.819 1.82 1.821 1.822 1.823 1.824 1.825 1.826 1.827 1.828-5

-4

-3

-2

-1

0

1

Time [s]

Val

ve c

urre

nt [k

A]


Synchronous Voltage ReversalThyristor action

-30 -20 -10 0 10 20 30

-25

-20

-15

-10

-5

0

5

10

15

20

25

angle [deg]

uC [k

V]

Capacitor voltage: xC= 20.0 ohms, fN= 50 Hz, iL= 1.5 kA, uZ= -10 kV

-30 -20 -10 0 10 20 30-7

-6

-5

-4

-3

-2

-1

0

1

angle [deg]

iV [k

A]

Valve current: xC= 20.0 ohms, fN= 50 Hz, iL= 1.5 kA, uZ= -10 kV


Equivalent instantaneous voltage reversal

boost

boost

realvoltagereversal

equivalentinstantaneous

voltage reversal

thyristor current

a)

b)

c)

tF tZ


Idealized steady-state voltage

Uc

t

Line current

Thyristor action


Boost control

uC

iL iL iL

uC

∆u >0Z∆u =0Z

∆ϕ >0C

uC

∆u <0Z

∆ϕ <0C

Line current

Capacitor voltage

constantboost

increasingboost

decreasingboost


Outline TCSC control

boost controller

SVR trig pulse

generation

apparent Z evaluation

phasor evaluation

PLL

A ∕ B

Σ

A

B-XC0

kBref

re

im

pulsesiL uC

OCT

OVT

OCT: Optical Current TransducerOVT: Optical Voltage Transducer


Apparent impedance

𝑍𝑍𝑎𝑎𝑎𝑎𝑎𝑎 =∆𝑈𝑈∆𝐼𝐼

𝐼𝐼 + ∆𝐼𝐼 𝑈𝑈 + ∆𝑈𝑈


Apparent impedance for FSC and TCSC

iVsub

iLsub

iLsub

uCsub

uCsub

z = ------- = - j ---- xapp C

z = ------- = - j ---- ------------- xapp C= ?

uCsub

uCsub

iLsub

iLsub

fN

fN

fsub

fsub

i -iLsub Vsub

iLsub

xC

xC

fixed series capacitor

TCSC


10 Hz current in a fixed SC

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-1.5

-1

-0.5

0

0.5

1

1.5

iL [k

A]

Fixed series capacitor xC=20ohms, iL=1000A(50 Hz)+100A(10 Hz)

total line curentonly 10 Hz current

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-30

-20

-10

0

10

20

30

time [s]

uC [k

V]

total cap voltageonly 10 Hz voltage


DC injection

3.45 3.5 3.55 3.6 3.65 3.7

-2

-1

0

1

2

Lin

e cu

rren

t [kA

] d

c co

mpo

nent

[kA

]

3.45 3.5 3.55 3.6 3.65 3.7-2

-1

0

1

2

Thy

risto

r va

lve

curr

ent [

kA]

3.45 3.5 3.55 3.6 3.65 3.7-20

-10

0

10

20

Time [s]

Cap

acito

r vo

ltage

[kV

]


10 Hz current in a TCSC

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-1.5

-1

-0.5

0

0.5

1

1.5iL

[kA]

TCSC disturbed operation iL=1000A(50Hz)+100A(10Hz)

total line currentonly 10 Hz current

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-30

-20

-10

0

10

20

30

time [s]

uC [k

V]

total cap voltage currentonly 10 Hz voltage


SVR apparent subsynchronous impedance

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-100

-50

0

50

100

time (s)

diLi

ne (A

)



0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-100

-50

0

50

100

diLi

ne (A

)

xC=20.0 ohms, fN=50.0 Hz fSub=10.0 Hz

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-4000

-2000

0

2000

4000

duCa

p (V

)

time (s)



0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-100

-50

0

50

100

diLi

ne (A

)


0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-4000

-2000

0

2000

4000

duCa

p (V

)

time (s)



0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-100

-50

0

50

100

diLi

ne (A

)


0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2-4000

-2000

0

2000

4000

time (s)

duCa

p (V

)



0 0.05 0.1 0.15 0.2 0.25-100

-50

0

50

100di

Line

(A)

xC=20.0 ohms, fN=50.0 Hz fSub= 2.0 Hz

0 0.05 0.1 0.15 0.2 0.25-4000

-2000

0

2000

4000

time (s)

duCa

p (V

)2 Hz



0 0.05 0.1 0.15 0.2 0.25-100

-50

0

50

100di

Line

(A)

xC=20.0 ohms, fN=50.0 Hz fSub= 5.0 Hz

0 0.05 0.1 0.15 0.2 0.25-4000

-2000

0

2000

4000

time (s)

duCa

p (V

)5 Hz



0 0.05 0.1 0.15 0.2 0.25-100

-50

0

50

100di

Line

(A)


0 0.05 0.1 0.15 0.2 0.25-4000

-2000

0

2000

4000

time (s)

duCa

p (V

)10 Hz


TCSC impedance characteristics

SSR Mitigation ExampleTCSC

Screening Studies


5 10 15 20 25 30 35 40 45-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4y ,

Ele

ctric

al d

ampi

ng,

De [

-]

Torsional frequency [Hz]

No SCFSCTCSC


RTDS Tests


∆W

Te

Tm

Subsynchronous mechanical

frequency injection

∆ Y

ZLine TCSC

Synchronousmachine

VoltageSource

15 20 25 30 35 40 45 50-14

-12

-10

-8

-6

-4

-2

0

2

4S1:Mode 5 CAP FAT, S2:Mode 5 BLK FAT

Mechanical frequency [Hz] Mechanical frequency [Hz]

Ele

ctric

al d

ampi

ng [t

orqu

e pu

/ spe

ed p

u] E

lect

rical

dam

ping

[tor

que

pu/ s

peed

pu]


RTDS Tests


SSR Mitigation ExampleTCSC and FSC

RTDS Tests


∆W

Te

Tm

Subsynchronous mechanical

frequency injection

∆ Y

ZLine TCSC FSC

Synchronousmachine

VoltageSource

15 20 25 30 35 40 45 50-70

-60

-50

-40

-30

-20

-10

0

10S1:Mode 4 CAP FAT, S2:Mode 4 BLK FAT

Mechanical frequency [Hz] Mechanical frequency [Hz]

Ele

ctric

al d

ampi

ng [t

orqu

e pu

/ spe

ed p

u] E

lect

rical

dam

ping

[tor

que

pu/ s

peed

pu]

SSR Mitigation ExampleTCSC and FSC

RTDS Tests


hector latorre, abb facts, 201611- -24 tcsc introduction ... · tcsc introduction and its...

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