2. CONTENTS
SWITCH GEAR
GIS – GAS INSULATED SWITCH GEAR
COMPONENTS OF GIS
TYPES OF GIS
DC SWITCHGEAR
COMPACT DC GIS
TECHNICAL DATA
ADVANTAGES
REFERENCE
26-11-2014HVDC Seminar
2
3. SWITCH GEAR
Switchgear is the combination of electrical disconnect switches, fuses or circuit
breakers used to control, protect and isolate electrical equipment.
used to de-energize equipment to allow work to be done and to
clear faults downstream.
It is directly linked to the reliability of the electricity supply.
The high-voltage switchgear was invented at the end of the 19th century for
operating motors and other electric machines.
The technology has been improved over time and can now be used with voltages
up to 1,100 kV
26-11-2014HVDC Seminar
3
5. GIS – GAS INSULATED SWITCHGEAR
GIS is a metal enclosed switchgear.
SF6 gas is used as insulation between live
parts of the equipment's and earthed metal
enclosure.
GIS is available from 12 KV system to 800
KV system.
For establishing electrical substation in very
limited place SF6 insulated electrical
switchgear plays a major role.
420 kV Gas Insulated Switchgear
26-11-2014HVDC Seminar
5
6. COMPONENTS OF GIS
Electrical bus bars.
Electrical isolators or disconnectors.
Circuit breakers.
Current transformers.
Voltage transformers.
Earth switches.
Surge arrestors or lightning arresters.
The substation, assembled by gas insulated switchgear, is popularly known as Gas
Insulated Metal Enclosed Substation (GIMES).
26-11-2014HVDC Seminar
6
7. TYPES OF GIS
The GIS systems available depending upon their constructional feature are :
• Isolated Phase GIS
• Integrated 3 Phase GIS
• Hybrid GIS System
• Compact GIS
• Highly Integrated GIS System
26-11-2014HVDC Seminar
7
8. DC SWITCH GEAR
The DC switchgear that is part of the converter station currently uses air-insulated
technology and thus requires a large amount of space.
Because of air's relatively low insulating capability, the individual components can
only be installed with a large amount of space between them and also between
them and the earth potential.
The air-insulated DC switchgear that has been used on Siemens' converter
platforms until now requires about 4,000 cubic meters of space, thereby requiring
halls that are from two to ten meters high.
Space is a decisive cost factor both out at sea as well as in urban population
centres.
26-11-2014HVDC Seminar
8
9. DC SWITCH GEAR
Since controlling an electric field under direct current is very complex, it had not
been possible until now to build gas-insulated, compact DC switchgear for HVDC
transmission applications.
The development of a new isolator, which can permanently withstand the demands
of high-voltage direct currents, made it possible to develop the first DC GIS
switchgear
The innovative, compact DC CS (Direct Current Compact Switchgear) has the same
capacity but needs only 200 cubic meters, thereby allowing space savings of up to
95 %.
26-11-2014HVDC Seminar
9
10. COMPACT DC GIS
At the Cigré Conference in Paris, Siemens presented the first compact gas-insulated switchgear
(GIS) for high-voltage direct current applications.
The 320-kilovolt (kV) GIS uses up to 95 % less space.
On an offshore platform, the platform size can be decreased by approximately 10 %.
26-11-2014HVDC Seminar
10
12. ADVANTAGES
Compact gas-insulated switchgear requires 95 % less space compared to air-insulated
unit.
Helps substantially reduce costs in the offshore realm.
module-based design makes it flexible and simple to set up.
Enables the use of cost-efficient shipping and transportation methods.
Can be reliably installed under demanding environmental conditions.
maximum reliability and low maintenance costs.
Cornerstone of the new direct current transmission portfolio based on gas-insulation
technology.
26-11-2014HVDC Seminar
12
13. APPLICATION
26-11-2014HVDC Seminar
13
Between converter transformer and converter valves.
DC switchyard.
DC traction power supply systems.
Transition station (enabling compact transition from cable to overhead line.)
Multi-terminal station.