characteristics of multiphase transmission lines lecture 11 power engineering - egill benedikt...
TRANSCRIPT
26-Oct-11
1Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Characteristics of Multiphase Transmission Lines
26-Oct-11
2Lecture 11 Power Engineering - Egill Benedikt Hreinsson
The Electrical Transmission LineThe major components
are:• Shield (ground) conductors for
lightning protection.• Tower (lattice or tubular)• Phase conductors
(Transposed?, Bundled conductors?)
• Insulators (V string shown)• Foundation and grounding
grounding grounding
Foundation
26-Oct-11
3Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Examples of Transmission Line Towers
a) Low voltage tower with ground conductor
b) Medium voltage towerc) Concrete towerd) 110-380 kV towere) 110-220 kV tower
Source: Happoldt/Oeding: Elektrische Krafwerke und Netze.
26-Oct-11
4Lecture 11 Power Engineering - Egill Benedikt Hreinsson700-800 kV Transmission lines in Canada and Russia
Conductor bundles
Source: Happoldt/Oeding: Elektrische Krafwerke und Netze.
26-Oct-11
5Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Electrical Transmission Towers
Conductor bundles
26-Oct-11
6Lecture 11 Power Engineering - Egill Benedikt HreinssonSteel and Wooden Transmission Structures in Iceland
SteelWood
26-Oct-11
7Lecture 11 Power Engineering - Egill Benedikt HreinssonSteel and Wooden Transmission Structures in Iceland 145-420 kV
•The size and type of towers will generally depend on voltage, climate and general conditions along the right of way
Source: Landsnet, Grid operator, Reykjavik
26-Oct-11
8Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Transmission towers, Hellisheiði, Iceland
26-Oct-11
9Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Transposition of Transmission Lines•Objective: To obtain phase symmetry with the
approximate same average inductance and capacitance between phases and to earth for the total line length
26-Oct-11
10Lecture 11 Power Engineering - Egill Benedikt Hreinsson
LJªSIFOSS 66 kV
T S R
T S R T S R
T S R
T S R
132 kV
S
T
S
R
T
R
HRYGGSTEKKUR
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
T S R
S
T
R
BLANDA
132 kVS
T
R
T
S
R
T S R
T S R
BºRFELL
220 kV
132 kV
PRESTBAKKI
132 kV
KRAFLA
309 312 669 672
363 265 138
920
923
18
314
631
HªLAR
132 kV
132 kV
133 126
74
77
4
6
65
68
RAFVEITA
HAFNARFJ
S S
TT
RR
T
S
R
HRUTATUNGA
LAXñRVATN
SR T
132 kV
VARMAHLIï
361 167
TSR
T S R
66 kV
LAXñ
132 kV
ÑRAFOSS
132 kV
220 kV
S
T
R
KORPA
S
T
R
HAMRANES
132 kV
S
T
RGEITHñLS
S
T
R
S
T
RHAMRANES
220 kV
220 kV
ÑSAL
S
T
RGLERñR-
SKªGAR
132 kV
S
R
T
132 kV
KªPASKER
151
220 kV
220 kV
HRAUNEYJAFOSS
R TS
132 kV
VATNSHAMRAR
132 kV
A5
S
T
R
S
T
R
S
T
R
S
T
R
T
S
R
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
S
R
T
S
R
T
S
R
T
T
R
S
T
S
R
T
S
R
S
T
R
RST
RST
RSTS TR
S TR S TR
S TR S TR
S TR
S TR
S TR
S RT
S RT
S
R
T
T
R
S
RS T
TS R
TS R
KR2
LV1GL1
HT1
VA1
BR1
HVERAGERïI SELFOSS
HG1 SE1
KO1
S
R
T
EL1
HF1
HN2
HN1
SU1
ÑS2
ÑS1
MJ1
S
R
T
BL1
S
R
T
BL2
S
R
T
RA1
TE1
RST
PB1
Hª1
SI4SI3
S
T
R
SO2
S
T
R
SO3
BU2
LA1
LJ1
Aï7
SN1
S
T
R
R
132 kVT
S
R
T
S
R S
T
R
S
T
'
SEM OG HN1 OG HN2
GILDIR FYRIR ÑS1 OG ÑS2
'
Bº1
'
GE1RST
T
S
R
VEGAMªT
'ANDAKILL
S
R
TVATNS-
HAMRAR
66 kV
EYVINDARñ
STEKKUR
ÑRAFOSS
T S R
RANGñRVELLIR
66 kV
66 kV
66 kV
DALVÑK
RARIK
11 kV
132 kVS
R
TTEIGARHORN
S
T
R
Bº3
GEITHñLS
132 kV
220 kV
ìINGVALLASTRÆTI
66 kV
MJªLKñ
132 kV
BRENNIMELUR
NA1 NA2
STUïLAR
S TR
HRYGG-
66 kV
VELLIR
132 kV
RANGñR-
S
R
T
KR1
DALUR
GEIRA-
SI2
T S R
S TR
RST
Bº3
Bº2144218 T
R
S
66
NORïURñL
MELUR
BRENNI-
132 kV
HR1
T
S
R
SANDSKEIï
220 kV
Jñ1
JñRNBLENDI
KOLLUGERïI
SULTARTANGI
220 kV
NE1
VELLIR
NESJA- A3
S
T
R
S
T
RAKRANES
66 kV
AK1
AKRANES
MELUR
BRENNI-
66 kV
ANDAKÑLL
SP 3
132 kV
SIGALDA
220 kV
SIGALDASP1 SP2
SP2 SP1
SP2 SP1
SP5
SP4
SP2
SP1
SP2
SP1
BºRFELL
13.8 kV
T
S
R
HVOLS-
VÖLLUR
66 kV
FLºïIR
66 kV
SP4
BºRFELL
66 kV
SP5
R-FASI (L1)
S-FASI (L2)
T-FASI (L3)
T S R
220 kV
VATNSFELL
T S R
ST1 STEINGRÑMSSTÖï 66 kV
Dags. Nafn Næsta bl. -
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
Ferli Sæti Staîur
FASARÖï OG SNºNINGAR. 220 - 132 - 66 kV
YFIRLITSMYND HñSPENNUKERFIS 12. 2002
UNNIï ºR ELDRI ºTGñFUM. FRñ FEB.97, ñGº.98 OG NªV.99Verknúmer: 13-109-101
Blaî 1
Dags.12.2002
ºtg. A
= ++Kvarîi: 0
1 2 3 4 5 6 7 8 9 10 11 12
1 2 3 4 5 6 7 8 9 10 11 12
AFL OG ORKA EHF
VERKFRÆïISTOFAN
Yfirf. BreytingLV/VAO
Gert aKKS
Hannaî bSB/KKS
Dags. 12.2002 c
Stærî: A1
Teikningarnr. 130-109-101-0004 (FASA1202.PRT)
Verkfræîistofan Afl og Orka ehf
Samòykkt LV: BG
LANDSVIRKJUN
26-Oct-11
11Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Transposed HV line in Hellisheiði, Iceland• A familiar view from the
east in Hellisheiði, showing 2 adjacent towers in the HV line from Sog hydro to Reykjavik (Geithals). In these 2 towers next to each other transposition takes place and the conductors are rotated
26-Oct-11
12Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Distribution line13.8 kV
Transformer
240/120V line
Fuse and disconnector
Telephone line
Distribution Cable13.8 kV
Distribution line and Transformer in North America
26-Oct-11
13Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Phase Conductors
• Transmission lines use stranded aluminum conductors.
• Typical type of conductors are:– Aluminum-Conductor-steel -
Reinforced (ACSR)– All-Aluminum (AAC)– All-Aluminum Alloy (AAAC)
• Shield Conductors– Aluminum-clad-steel (Alumoweld)– Extra-High-Strength-Steel
ACSR Conductors
Most frequently used is the ACSR conductor. The steel provides mechanical strength, and the aluminum conducts the current.
Aluminum strands2 layers, 24 conductors
Steel strands7 conductors
Transmission Line Conductors
26-Oct-11
14Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Cross Section of Conductors
Steel reinforcement
Winding of layers on opposite directions
26-Oct-11
15Lecture 11 Power Engineering - Egill Benedikt HreinssonAluminum Conductor Steel Reinforced (ACSR) Conductors
Steel reinforcement
Winding of layers on opposite
directions
26-Oct-11
16Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Stranding of ACSR/ACAR
ACAR ACSRSource: Soutwire Cable Co.
26-Oct-11
17Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Transmission Line Insulators
Cup and pin Insulator Insulator chain
26-Oct-11
18Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Conductors - spacersExtra high voltage lines use bundled
conductors:– to reduce corona discharge by
reducing the maximum electrical field near the conductor.
– to increase current carrying capacity.
• Bundles with two, three and four conductors are used.
• The distance between the conductors in the bundle is maintained by steel or aluminum bars (spacers) as indicated in the figure.
d
d
r
d
r
d
r
Bundled conductors
26-Oct-11
19Lecture 11 Power Engineering - Egill Benedikt Hreinsson
Bundled conductors• More than one conductor per
phase for higher voltages• Approximate increase in the
number of conductors:– 0-400 kV: 1 conductor per phase– 400-500 kV: 2 conductors per
phase– 500-700 kV: 3 conductors per
phase– 700-800 kV: 4 conductors per
phase– 80-1200 kV: 6-12 conductors
per phase (experimental)
26-Oct-11
20Lecture 11 Power Engineering - Egill Benedikt HreinssonThe Electrical Field in the Vicinity of Conductor Bundles
The electrical field is at maximum at the outer edge of the conductors
26-Oct-11
21Lecture 11 Power Engineering - Egill Benedikt Hreinsson
765 kV and 1100 kV Bundles
26-Oct-11
22Lecture 11 Power Engineering - Egill Benedikt HreinssonThe Electrical Field in the Vicinity of Transmission Lines
26-Oct-11
23Lecture 11 Power Engineering - Egill Benedikt HreinssonThe Magnetic Field in the Vicinity of Transmission Lines
26-Oct-11
24Lecture 11 Power Engineering - Egill Benedikt Hreinsson
References• O.I. Elgerd: Electric
Energy Systems Theory. McGraw Hill
• J.D Glover, M.S. Sarma: Power system Analysis and Design, Brooks/Cole 2002
• M.E. El-Hawari: Electrical Energy Systems, CRC Press, 2000