EE 5

200

- Lec

ture

16

Mon

Oct

5, 2

015

Topi

cs fo

r Tod

ay:

•A

nnou

ncem

ents

•M

atla

b to

be

inco

rpor

ated

in u

pcom

ing

Hm

wks

.•

Offi

ce h

rs: 2

:05-

2:55

pm M

,W; 1

0-11

am F

riday

•O

ffice

: EE

RC

614

.P

hone

: 906

.487

.285

7•

Rec

omm

ende

d pr

oble

ms

from

Ch.

4,5

solu

tions

pos

ted

•N

ext:

Tran

smis

sion

Lin

e C

Par

amet

ers,

Cha

pter

6

Cha

pter

4 -

Ser

ies

Res

ista

nce

of T

rans

mis

sion

Lin

es•

Con

duct

or d

ata

(link

s pr

ovid

ed o

n w

eb p

age)

•S

pira

ling,

effe

ctiv

e le

ngth

is a

bout

2%

long

er•

Ser

ies

Res

ista

nce,

tem

pera

ture

cor

rect

ion

Cha

pter

5 -

Ser

ies

Indu

ctan

ce o

f Tra

nsm

issi

on L

ines

•S

elf-i

nduc

tanc

e of

a c

ondu

ctor

•R

evie

w o

f mut

ual i

nduc

tanc

e co

ncep

ts•

Mut

ual i

nduc

tanc

e be

twee

n 2

cond

ucto

rs•

Indu

ctan

ce m

atrix

for g

roup

of c

ondu

ctor

s

Win

d-in

duce

d os

cilla

tion

(from

Wik

iped

ia)

Win

d ca

n ge

nera

te th

ree

maj

or m

odes

of o

scill

atio

n in

sus

pend

ed c

able

s:[4

]

•G

allo

p ha

s an

am

plitu

de m

easu

red

in m

etre

s an

d a

frequ

ency

rang

e of

0.08

to 3

Hz;

•A

eolia

n vi

brat

ion

(som

etim

es te

rmed

flut

ter)

has

an

ampl

itude

of

mill

imet

res

to c

entim

etre

s an

d a

frequ

ency

of 3

to 1

50 H

z;•

Wak

e-in

duce

d vi

brat

ion

has

an a

mpl

itude

of c

entim

etre

s an

d a

frequ

ency

of 0

.15

to 1

0 H

z

The

Sto

ckbr

idge

dam

per t

arge

ts o

scill

atio

ns d

ue to

aeo

lian

vibr

atio

n; it

is le

ssef

fect

ive

outs

ide

this

am

plitu

de a

nd fr

eque

ncy

rang

e. A

eolia

n vi

brat

ion

occu

rs in

the

verti

cal p

lane

and

is c

ause

d by

alte

rnat

ing

shed

ding

of v

ortic

eson

the

leew

ard

side

of t

he c

able

. A s

tead

y bu

t mod

erat

e w

ind

can

indu

ce a

stan

ding

wav

e pa

ttern

on

the

line

cons

istin

g of

sev

eral

wav

elen

gths

per

span

.[4] A

eolia

n vi

brat

ion

caus

es d

amag

ing

stre

ss fa

tigue

to th

e ca

ble[

5] a

ndre

pres

ents

the

prin

cipa

l cau

se o

f fai

lure

of c

ondu

ctor

stra

nds.

[4] T

he e

nds

ofa

pow

er li

ne s

pan,

whe

re it

is c

lam

ped

to th

e tra

nsm

issi

on to

wer

s, a

re a

tm

ost r

isk.

[5] T

he e

ffect

bec

omes

mor

e pr

onou

nced

with

incr

ease

d ca

ble

tens

ion,

[5] a

s its

nat

ural

sel

f-dam

ping

is re

duce

d.

Tran

smis

sion

Lin

e V

ibra

tion

Dam

pers

-

Top:

Tra

ditio

nal S

tock

brid

ge -

2 fre

quen

cies

Bot

tom

: Spi

ral t

ype

Tran

smis

sion

Lin

e V

ibra

tion

Dam

per -

Fou

r Res

onan

t Pea

ks

Spacer Dampers, Stockbridge Dampers, Recorders and Warning Spheres

Triple Spacer DamperPFISTERER’s spacer dampers are specifically designed and coordinated to providedamping against conductor motions caused by wind. In particular the spacer damperscontrol the levels of aeolian vibration and subspan oscillation within the acceptedsafety limits, under all service conditions and for the expected life time of the line.PFISTERER offers a complete range of spacer dampers for two, three, four and sixbundles, with spacing ranges from 300 to 600 mm.

Stockbridge DamperPFISTERER’s range of stockbridge dampers is designed to dissipate energy from alltypes of conductors, shieldwires and OPGW cables caused by wind-induced motions.Many tests are needed to prove a successful damper design, which includescorrosion resistance, damping performance and fatigue behaviour. These tests arenecessarily supplemented by electrical tests in regard to corona and RIV and areperformed in PFISTERER’s own laboratories.

Vibration RecorderAs the ultimate means of checking damping systems or to investigate the cause ofconductor damages, PFISTERER offers vibration recorders. These can be used toeasily measure vibrations on lines in operation. Moreover, the component of windvelocity acting perpendicularly to the line and the ambient temperature can berecorded. The conductor vibration data can be recorded and converted. Byautonomous, long-term and direct measurements, an assessment of all critical linesections can be made.

Warning SpherePFISTERER’s warning sphere has a diameter of 600 mm and is especiallymanufactured to avoid the loss of colour and UV-degradation by using a specialmaterial and painting technology. Optimisations have been applied to eliminate clamploosening and audible noise due to vibration. Installation costs can be reduced thanksto its simple installation. The sphere is available in various colours and for severalconductor diameters.

Spacer Dampers, Stockbridge Dampers, Recorders and Warning Spheres http://us.pfisterer.com/p-freileitung_feldabstandhalter.php?nav=overheadl...

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