1. UHV Equipment Requirements Anton Janssen
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 MOSA Uc/t2 RV= kpp*Ur 2/3 U1=0.75*RV U1/t1 Uc=kaf*U1/0.75
t1=U1/RRRV
t2=?*t1
U1/t1
ITRV
RRRV td

4. Kpp Kpp depends on X0/X1 ratio X0/X1 for transformers << 1.0
X0/X1 OH-lines >> 1.0
UHV: long OH-lines, heavy transformers ->
In UHV substations X0/X1 less than at EHV ->
Kpp = 1.2 instead of 1.3

5. RRRV UHV OH-lines:. large diameter conductor bundles
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> RRRV< 3 kV/µs

6. Kaf, t2, t3 At UHV less damping expected, but limited experience, therefore proposed: for T100 Kaf from 1.4 to T T T (covering LLF) t2 calculated by simplified model and compared with TEPCO-network, proposed: for T100 t2 from 4*t1 to 3*t T60 t2 from 6*t1 to 3*t1 (covering LLF~IEEE) for T30, T10 t3 = Uc/RRRV

7. ITRV. Applicable to AIS and MTS (HGIS) substations
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: ti = 1.5 μs (Powergrid 1200 kV) * For 260 Ω ITRV covered by SLF without tdL * What about 325 Ω? * What about ITRV traveling waves at both sides?

8. ITRV (PowerGrid 1200 kV)
80 m
240 m
160 m m
120 m
> 40 m

9. SLF, LLF. Z = 330 Ω. tdL = 0. 5 µs. LLF covered by T60, T30, T10 with:
SLF, LLF * Z = 330 Ω * tdL = 0.5 µs * LLF covered by T60, T30, T10 with: T60 t2 = 3*t1 T60 kpp = 1.2, kaf = 1.5 T30 kpp = 1.2, kaf = T10 kpp = 1.2, kaf = 1.76

10. TLF. new specification ~ IEEE draft C37. 06
TLF * new specification ~ IEEE draft C * TLF-current from R10 series (close to T30/T10) * t3 = k x Ur with k = 6, based on information of I surge cap. of some UHV transformers * kpp = 1.3, kaf = 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°
Out-of-Phase * at UHV large out-of-phase angles possible: 180° * with low kpp, at 180°, first pole RV ~ 2.0 pu * Iop and RRRV are proportional to RV * Uc is proportional to RRRV and line length * at 105º: RV, Iop, RRRV and Uc will be 20% lower * not enough information about probability, Iop and kaf in service

12. Impact of MOSA on Uc

13. Impact of MOSA on Uc. there is a clear impact of UHV MOSA on Uc
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
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. Thank you for your attention Thank you for your input!!
WG A3.22:
Thank you for your attention
Thank you for your input!!