1. Development and testing of 1100 kV GIS
HOLAUS Walter, RIECHERT Uwe, SOLOGUREN Diego, KRÜSI Urs
ABB Switzerland Ltd.
ELK-5 equipment at ”Jingmen” substation
IEC/CIGRE UHV Symposium, New Dehli

2. Development of UHV GIS: Environment
Only a few potential markets worldwide e.g. China, India, ..
Huge development effort for a limited number of customers
Chinese market supplied by local suppliers
International standards (so far) do not cover 1100 kV AC
Development is based on customer specification
Limited possibilities to test 1100 kV GIS equipment
Only a few test labs worldwide are equipped for UHV testing
Test items and test poles tend to be huge -> transport & space limitations
Rated power of one UHV GIS bay is 6‘9 GW
Robustness is key factor for UHV GIS and other components
Substation layouts to support high availability
ABB finished UHV GIS development and type testing in 2008
Equipment assembled by Xian Shiky in China
Equipment is installed and in operation at “Jingmen” substation

3. ELK-5 GIS: Main ratings Um 1100 kV System Voltage 1000 kV
Rated lightning impulse withstand level 2400 kV
Rated short-duration pfwv to ground 1100 kV, 1 min
Rated short-duration pfwv across isol. distance kV
Rated lightning impulse wv. across open gap kV
Rated switching impulse wv. to ground 1800 kV
Rated switching impulse wv. across open gap kV
Rated frequency 50 Hz
Rated normal current for feeder circuits 4000 A
Rated normal current for main busbar circuits 8000 A
Rated short time withstand current 50 kA, 3s
Rated peak withstand current 125 kA
Partial discharge level of each GIS component <3pC at Um/3

4. Layout proposal for Hybrid GIS, 2 CB layout
BB1
15 m
Exit
18.5 m
BB2
Top view 1 phase:
DES CT CB CB
drive
Closing resistor

5. Layout characteristics
All GIS equipment close to floor level
“Hook” shape compensates elongations
All drives placed within 1.5 m height
Density sensors close to floor level
No platforms required for GIS installation
CB drive and CB tank can be removed without disassembling other GIS parts
Only small steel structures required
Biggest transport unit less than 8 tons
Most spacers are arranged vertically

6. Design of 1100 kV circuit breaker
Existing interrupting units applied
4 interrupter units connected in series,
A high-speed switch for closing resistor
One drive operating interrupters and switch
Closing resistor in separate tank as an option
Overall weight: 7.5 tons CB
Switch R
9300 mm
Drive
Circuit breaker: 4 interrupters
Linkage CO
switch
Closing resistor

7. Drive energy for 1100 kV circuit breaker
Calculation of drive energy i1 i2 i3 ix
Result
4 interrupting units connected in series require the least drive energy for 1100 kV
Using less interrupting units increases opening speed and drive energy demand

8. Thermal dimensioning of closing resistor
Example: Assumptions for simulation
Results for this simulation
2 x Phase opposition within 30 min,
11 ms pre-insertion each
Resistance value: 560 Ohm at 20°C
Starting temperature 50 °C
Cooling time constant: 3000 s
Resistance value changes due to Temperature Voltage
Dissipated Energy 91.7 MJ
Temperature rise °K
Max temp of resistor discs °C
Cooling during 30 min
First PO insertion
Second PO insertion
Resistance Ohm
Energy MJ
Temperature K

9. Size comparison ABB circuit breaker & drive
1100 kV with closing resistor
4 interrupters
HMB 16
Linkage
CO switch
Closing resistor
550 kV with closing resistor
2 interrupters + closing resistor
HMB 8
550 kV
2 interrupters
HMB 8
300 kV
1 interrupter
HMB 4

10. Size comparison ABB circuit breaker & drive
550 kV with closing resistor
2 interrupters + closing resistor
HMB 8
550 kV
2 interrupters
HMB 8
300 kV
1 interrupter
HMB 4

11. Voltage grading along the 4 interrupters
Static calculations
Simulation circuit
Voltage grading capacitance
Inner: CP=2.5 nF, Outer: CP=2.7 nF
Stray capacitance: CE=75.5 pF
AC 50 Hz calculations
Voltage grading factor: 1.056
Dynamic voltage distribution
Series resistance: 25 Ohm
Inductance: 500 nH
Using worst-case assumptions for tolerances
Specific calculations required for half-pole testing

12. Dielectric Type Tests AC: 1100 kV, 1 min AC-AC: 1100 + 635 kV
UHV PD
Sensor 1
Sensor 2
Sensor 3
Sensor 4
AC: 1100 kV, 1 min
AC-AC: kV
LI-AC: kV
SI: 1800 kV
SI-AC kV
Specific remarks
Lightning impulse voltage
Overshoot of 7 – 10 %
Combined voltages
Overcoupling of 20 %
PD measurement
Background noise level of 7 pC at 1000 kV
Non-conventional PD measurement methods (UHF)

13. Power tests on UHV Circuit breaker
Breaking and switching tests at XIHARI lab as half-pole tests
Two interrupters under test
The other two breaks act as auxiliary breaker.
T100a and T100s additionally as full-pole tests
TRV voltages at both sides of the circuit breaker
The enclosure was connected to one side TRV

14. Examples: TRV’s from power testing
T100a
Major loop
Half pole test
T60a
Half pole test
Voltage
Time [ms]
Voltage
Time [ms]

15. Making Tests T100s(a)
Laboratories have synthetic making circuits capable to ignite 550 kV CB
For longest pre-striking arc in the 1100 kV breaker, SF6 pressure was reduced to 0.2 MPa
The pre-arcing time of the 1100 kV circuit breaker with four breaks was similar to the pre-arcing time of a 550 kV circuit breaker with two breaks of the same design.
Advantages by reducing pressure
Simple measure to perform a making test without having the full making voltage available.
Multiple making operations without disassembly
Correct mechanical forces for the drive
Correct pre-arcing distance

16. Design of TV5 disconnector
Designed as 90 ° angle disconnector
Existing DES drive from ABB 550 kV applied
No linkage between the three phases
No VFT resistor applied
VFT calculations show, that VFT resistor is not required. VFT levels remain below 2.2 pu.
BIL levels is 2.6 pu. This provides margins for VFT stress.
Enclosure as welded construction
Contact area optimized for improved bus transfer switching capability
Earthing switch as an option
Simple design with small number of parts
Moving contact
Fixed contact
Drive
Insulator
Insulator
Active parts of disconnector

17. UHV Disconnector switching tests at STRI lab
Test set-up for disconnector switching tests in STRI, Ludvika, Sweden
Test circuit TD2
TD1, TD2, TD3 tests performed
Huge effort for testing
Max. VFT peaks of pu measured
Confirmed simulations
Average arcing time 280 ms at TD2

18. Conclusions
UHV GIS equipment rated 1100 kV, 4/8 kA, 50 kA has been designed and fully type tested
Design of the UHV GIS components has been done for optimum layouts and flexibility in GIS or hybrid GIS substations
Energization done in 12/2008 at Jingmen substation in China
Although test laboratories have invested in facilities for testing at UHV voltage levels, type testing remains a very challenging task