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18 Νοε 2013 (πριν από 3 χρόνια και 7 μήνες)

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1

Report 4.1


on behalf of WG A3.22

UHV Equipment Requirements

Anton Janssen

2

CIGRÉ WG A3.22

Scope: Review state
-
of
-
the art of project specific and national



technical specifications for all substation equipment



within scope of SC A3, at voltages exceeding 800 kV.



Recommend future specifications and standardizations



for 1100 and 1200 kV equipment and provide, to IEC



TC 17, technical background information.


General information in Report 3.1, and the presentation of
Report 3.1, by the convenor Hiroki Ito.


UHV circuit
-
breaker information in Report 4.1.


3

TRV envelope






t
d

U
1
/t
1

Uc/t
2

RRRV

RV=
k
pp
*Ur
2
/
3

U
1
=0.75*RV

Uc=
k
af
*U
1
/0.75

t
1
=U
1
/RRRV

t
2
=
?
*t
1

ITRV

MOSA

4

K
pp




K
pp

depends on X
0
/X
1

ratio


X
0
/X
1
for transformers << 1.0

X
0
/X
1
OH
-
lines


>> 1.0


UHV: long OH
-
lines, heavy transformers
-
>


In UHV substations X
0
/X
1

less than at EHV
-
>


K
pp
= 1.2 instead of 1.3

5

RRRV


UHV OH
-
lines:


* large diameter conductor bundles

* heavy sub
-
conductors

* no bundle contraction before interruption


for first and last clearing pole
Z < 330
Ω


At 50 kA, 50 Hz rating (n is number of OH
-
lines):

for T100 with n>3 RRRV< 2 kV/µs

for T60 with n>1 RRRV< 3 kV/µs

6

K
af
, t
2
, t
3


At UHV less damping expected, but
limited
experience
, therefore proposed:

for T100 K
af

from 1.4 to 1.5


T60


1.5


T30


1.54


T10


1.76 (covering LLF)


t
2

calculated by simplified model and compared
with TEPCO
-
network, proposed:

for T100 t
2
from 4*t
1

to 3*t
1



T60 t
2

from 6*t
1

to 3*t
1

(covering LLF~IEEE)


for T30, T10 t
3
= Uc/RRRV

7

ITRV



* Applicable to AIS and MTS (HGIS) substations


* Surge impedance of busbars and bays for


instance
263
Ω to 325

Ω (Powergrid 1200 kV)


* First reflections: t
i

= 1.5 μs (Powergrid 1200 kV)


* For 260 Ω ITRV covered by SLF without t
dL



* What about 325 Ω?


*
What about ITRV traveling waves at both sides?



8

ITRV (PowerGrid 1200 kV)
































80 m

> 40 m

120 m

160 m 60 m

240 m

9

SLF, LLF


* Z = 330
Ω

* t
dL

= 0.5 µs


* LLF covered by T60, T30, T10 with:


T60

t
2

= 3*t
1


T60

k
pp

= 1.2, k
af

= 1.5


T30

k
pp

= 1.2, k
af

= 1.54


T10

k
pp

= 1.2, k
af

= 1.76

10

TLF


* new specification ~ IEEE draft C37.06


* TLF
-
current from R10 series (close to T30/T10)


*

t3 = k
x
Ur with k = 6,
based on information of



I
0.21


surge cap. of some UHV transformers



* k
pp

= 1.3, k
af

= 0.9*1.7


* 1.3*0.9*1.7 < 1.2*1.76 (T10)

11

Out
-
of
-
Phase


* at UHV large out
-
of
-
phase angles possible: 180
°


* with low k
pp
, at 180
°
,

first pole RV
~ 2.0 pu


* I
op

and RRRV are proportional to RV


* Uc is proportional to RRRV and line length


* at 105º: RV, I
op
, RRRV and Uc will be 20% lower


*
not enough information about probability, I
op



and k
af
in service

12

Impact of MOSA on Uc

13

Impact of MOSA on Uc


* there is a clear impact of UHV MOSA on Uc


* variation in MOSA characteristics and application
require to apply some margin above SIPL


* another margin is required to be specified between Uc
and SIPL plus margin


* due to both margins effect of MOSA on specified Uc
for T100, T60 is nihil or small


* due to load side part of TRV at LLF and TLF effect of
MOSA on Uc for T30, T10 is nihil or small

14

Impact of opening resistors



* opening resistors advantageous to further
reduce switching surges


* Opening resistors positive effect on Uc and
RRRV for both main and auxiliary contacts


* Caution for capacitive current and OP
switching, in some cases


* Application and specification very user
specific




15

WG A3.22:



Thank you for your attention


Thank you for your input!!