Table of Contents
What is GIS in a substation?
A gas insulated substation (GIS) is a high voltage substation in which the major conducting structures are contained within a sealed environment with a dielectric gas known as SF6, or sulfur hexafluoride gas as the insulating medium.
What is GIS electrical system?
Gas Insulated Switchgear (GIS) is the name for a unit that houses these components and circuits in a single gas tank with a compact footprint. Grounding devices that prevent electrical shock and lightning arresters that prevent dielectric breakdowns from lightning strikes are also included to enhance safety.
What is the difference between air insulated and gas insulated switchgear?
What’s the difference between AIS and GIS equipment? AIS uses air as the main insulating medium. AIS is further classified as metal-clad or metal-enclosed. Metal-clad switchgear has extensive barriers, shutters, primary bussing covered with insulation, and uses drawout vacuum circuit breakers to interrupt faults.
What is the need of gas insulated substation?
Gas insulated switchgear (GIS) is very compact form of switchgear. Because of the use of SF6 (sodium hexafluoride) insulation, the size of the switchgear reduces drastically. This product is normally used in medium and high voltage application. GIS is more safe, compact and maintenance-free as compared to AIS.
What are the advantages of GIS substation?
increase the cost of maintenance and equipment degradation. As indicated, the cost of a GIS indoor substation is much higher compared to an AIS substation, but the benefits of a GIS are by far more desirable and include high reliability, less space and far less maintenance.
What is the difference between air-insulated and gas insulated switchgear?
What is Gasgas Insulated Substation (GIS)?
gas insulated substation (GIS) is a high voltage substation in which the major conducting structures are contained within a sealed environment with a dielectric gas known as SF6, or sulfur hexafluoride gas as the insulating medium.
Is a gas isolated substation more expensive?
Even though a gas isolated substation will initially cost more than a similar air insulated substation, the economics may rationalize its installation where land is pricey, such as city centres. GIS may also be rationalized when a low profile substation is required to “hide” a substation.
How to set up GIs inside indoor or outdoor substations?
To set up GIS inside indoor or outdoor substation safety regulations are further described in IEC 61936-1. Installation regulations are presented to integrate factory assembled and type-tested GIS equipment. Demands of grounding, accessibility, fire protection, safety of walkways and other areas are described.
Why is SF6 gas used in substation insulation?
The SF6 gas provides the phase to ground insulation. As the dielectric strength of SF6 gas is higher than air, the clearances required are smaller. Hence the overall size of each equipment and the complete sub-station is reduced. The various modules are factory assembled and are filled with SF6 gas.