Gas-insulated switchgear (GIS) is a revolutionary technology that offers tremendous operational cost savings. It is particularly beneficial in spaces like urban offshore substations because it is easy to maintain and drives safe operations. As businesses look towards sharper energy management, GIS is the leading solution for smart infrastructure. Want to unlock the potential of GIS in your power systems? Read to the end!
1) What is Gas Insulated Switchgear?
Gas Insulated Switchgear (GIS) is an electrical equipment that is used to control and protect power systems. GIS is an advanced technology enclosed entirely in a compact metal case. Its individual parts are insulated using SF6 (sulfur hexafluoride) gas. Switchgear GIS members pose a number of advantages, lowering the danger of malfunctions.
Compared to air-insulated switchgear (AIS), GIS electrical is housed in a metal box, which makes it more suited to regions with limited area. GIS comprises several electrical components like transformers, circuit breakers, and disconnectors which are located inside a gas chamber. (we will discuss this in detail in the same blog).
The gas insulation prevents fault currents from flowing and ensures that the system is reliable even under harsh conditions. In this manner, power outages are mitigated and the equipment is protected. Moreover, switchgear GIS is such a powerful system that it does require much maintenance unlike other systems. Being sealed makes it impervious to dust, moisture, and pollution and therefore it does not need services as often as AIS.
Switchgear of this kind is common in modern electrical systems, used in power grids, renewable energy systems, and industrial applications. Well, they can be operated at high voltage while maintaining a relatively small size which suits modern needs.
2) Working Principle of GIS
Gas Insulated Switchgear (GIS) works by using an insulating gas to shield the system from short circuits. The gas used is usually sulfur hexafluoride (SF₆). The gas serves as an insulator preventing short circuits and ensuring system stability.
When electricity is brought into the GIS, it is received by various components like circuit breakers, busbars, and disconnectors. All of these parts work together to handle control, protection and distribution of power.
For GIS, the gas is kept at a high pressure for better insulation. This enables the switchgear to work with high voltages and not have a large spacing between the different components. GIS has an edge over AIS (Air Insulated Switchgear) as AIR relies on the gaps in air for insulation, GIS can work with far less space.
When a fault occurs, it stops the affected area without disturbing the rest part of the system. Ultimately, reducing time wastage and preventing outages.
3) Key Components of Gas-Insulated Switchgear
Gas Insulated Switchgear (GIS) consists of several key components that work together to control and protect electrical power systems. All these parts are encased in a gas-filled chamber to guarantee insulation and reliability.
- Circuit Breaker: GIS would be paralyzed without the circuit breaker since it is one of its most vital components. It disables electric flow automatically when a fault happens so that the system does not get damaged. It functions with the help of SF6 gas, which aids in arc extinguishing.
- Disconnector and Earthing Switch: For maintenance purposes, the disconnector cuts off a circuit from the power supply. The earthing switch grounds the system when it is safe to do so, shielding the system from electrical danger.
- Busbars: These are conductors that transfer GIS power from one section to another. Since they are encased in gas insulation, Busbars can withstand high levels of power without needing to be placed in large spaces.
- Current and Voltage Transformers: Gas-insulated transformers (GIT) are used to measure the values of monitoring and protection. A current (CT) transformer measures the current flowing while the voltage (VT) transformer takes the voltage measurement.
- Gas-Insulated Enclosure: This enclosure holds all the components of GIS and it is filled with SF6 gas. It is used to safeguard the system from external elements like dust, moisture, and damage which ensures its reliability over time.
- Control and Protection System: This subsystem controls all operations of GIS and locates faults within the system. It responsively manages issues that arise to ensure performance efficiency.
In managing power distribution networks, each component guarantees the safe and reliable operation of GIS.
4) Gas-Insulated Switchgear Applications
Due to its high reliability and ability to withstand enormous amounts of voltage, GIS is used in many industries around the world due to its compact design. It is perfect for use in locations where both spaces are limited or where the condition environment is a factor.
- Power GIS Substations
Power distribution makes wide use of GIS in substations. Because of the small land space available in city areas, it conveniently meets the requirements for reduced-size equipment. Moreover, low maintenance and dependable operation foster GIS’s popularity in urban power gis substations.
- Industrial Facilities And Plants
Dust, moisture, and pollutants make it harsh for industrial environments. Because of this environment, factories and manufacturing plants use GIS. The fact that GIS is enclosed and guarded from pollutants makes the system extremely useful.
- Renewable Energy Plants And Equipment
In comparison with the type of equipment, wind farms and solar power plants prefer using GIS for more efficient energy transfer. This is because GIS guarantees stable power flow and electrical fault prevention which is vital for renewable energy projects.
- Installations Offshore And Underground
Limited space is one of the main reasons why GIS is used in offshore and underground substations. The technology provides long-term survival by protecting it from water, salt and extreme weather conditions responsibly.
- Railways and Metro Systems
Railways and metro systems rely on GIS for energizing trains and signal equipment. Its small size and great efficiency make it possible to place it in tunnels and other confined spaces.
- Commercial and Residential Buildings
GIS provides high reliability and safety in power distribution for tall buildings and large commercial complexes. Its reduced maintenance and high safety standards make it ideal for modern infrastructure.
GIS is important in various sectors because of its far-reaching, urban-to-rural power distribution capabilities, ensuring safety and smooth operations.
5) Gas Insulated Switches Advantages and Disadvantages
Gas Insulated Switchgear (GIS) has its pros and cons. Knowing both gives you the insight needed to choose the right one for various uses.
- Advantages:
+ Compact Size: GIS is more compact than Air Insulated Switchgear(AIS). Its small size makes it suitable for several areas.
+ High Reliability: GIS has high reliability because of its fully enclosed casing. This protects it from dust, moisture, and pollution which prolongs its use life.
+ Low Maintenance: Compared to other systems, GIS does not require as much routine upkeep because it is less exposed to the elements. Unlike AIS, GIS needs no regular cleaning or inspections.
+ Enhanced Safety: GIS averts incidental contact with high-voltage parts. The risk of electrical faults and arc flashes is less due to metal enclosures and SF₆ gas insulation.
+ Better Performance in Harsh Conditions: Extreme weather, corrosive environments, and high altitudes do not hinder GIS functionality. Its application is common in industrial plants, offshore platforms, and underground tunnels.
+ Lower Noise Levels: GIS operates at a lower noise level during its functioning which is why it can be installed in residential and commercial areas.
+ Longer Lifespan: GIS has a longer life span. If properly handled, it can remain operational for about 30-40 years.
- Disadvantages:
– High Initial Cost: Advanced materials, technology, and manufacturing processes are some reasons GIS costs more than AIS. The price of SF₆ gas also increases the overall cost.
– Complex Installation: GIS is more difficult to install than other systems due to the specialized tools and skills required. Incorrect installation poses a serious risk that could impact performance and safety.
– SF₆ Gas Impact on the Environment: SF₆ gas is an extremely potent greenhouse gas. GIS consumes less gas compared to other SF₆-based equipment. However, the environmental concern still exists.
– Complex Fault Detection and Repair: As a sealed subsystem, GIS has challenges with detecting and repairing inefficiencies and faults. Repairs are often expensive and require high-end, specialized skills.
6) Gas Insulated Switchgear Vs Air Insulated Switchgear(AIS)
Gas Insulated Switchgear (GIS) and Air Insulated Switchgear (AIS) both perform the same purpose of serving an electrical distribution system, however, they are different in the aspects of design, insulation, and application. We break down the distinctions further below.
i) Insulation Medium
GIS: SF₆ is the best insulator for an easier and more effective quenching of an arc and gas that helps in quenching. Having SF₆ possess a high dielectric strength suggests that GIS is more compact and smaller in designs which is an advantage in high voltage or space constraining settings.
AIS: Uses air for insulating as it does not contain SF₆. Air has a definitely lower dielectric strength which means that the walls of a dielectric component have to be wider apart from each other. This implies that components of AIS would have a larger volume and take up much more space. This is ineffective for regions with a limited area.
ii) Defenses from External Risks
AIS: AIS is an acronym for Air Insulated Substation. It is susceptible to dirt and moisture, which greatly affects its performance. As a result, it is a good fit for areas with minimal changes in the environment. With regard to maintenance, more can be expected.
GIS: GIS refers to Gas Insulated Substations. They are ideal for areas prone to extreme weather conditions because the sealed design protects them from environmental dangers like dust, moisture, and pollution. Likewise, harsh conditions do not limit GIS performance.
iii) Performance and Reliability
GIS: For high-voltage systems, reliability is critical and unlike most, GIS is designed for this. Components are not exposed to dirt, allowing GIS to operate under an enclosed design. So, it is known for consistent performance regardless of the conditions.
AIS: It is less reliable because of its exposure to external elements. Air, humidity, and dust are some external components that can lead to wear and tear. This loss in capability due to these outside factors will further result in performance degradation over time.
iv) Maintenance Requirements
GIS: Need not much care because of its fully sealed design. With GIS being protected from dust, moisture, and pollution, it needs little attention. This makes GIS a preferable option for remote locations or regional areas with little access to regular maintenance.
AIS: Higher upkeep due to the weather exposure and pollution of components. The open structure of AIS makes it more vulnerable to dirt and moisture, requiring more frequent maintenance checks in order for the system to perform and function correctly.
| Feature | Gas Insulated Switchgear (GIS) | Air Insulated Switchgear (AIS) |
| Insulation Medium | SF₆ gas | Air |
| Size | Compact requires less pace | Large, requires more space |
| Installation | Complex requires skilled labour | Simple, easier to install |
| Cost | High initial investment | Lower initial cost |
| Maintenance | Low, sealed system | High, exposure to the environment |
| Reliability | High, protected from dust and moisture | Lower, affected by weather |
| Environmental Impact | Uses SF₆ gas (a greenhouse gas) | No harmful gases, eco-friendly |
| Lifespan | Longer, up to 40 years | Shorter, more wear over time |
| Usage | Urban areas, underground, offshore | In rural areas, outdoor substations |
7) Common GIS Failure Analysis and Solutions
Gas Insulated Switchgear (GIS) is designed for reliability and efficiency, but it can experience failures. Understanding common GIS failures and their solutions can help in minimizing downtime and improving system performance.
a) SF₆ Gas Leakage: With GIS, one of the most important and prevalent issues is SF₆ gas escape. SF₆ maintains the functionality of the unit’s insulation and arc-quenching, and any leak can cause damage. Leaks can stem from malfunctioning seals, joints, or valves as well to name a few.
- Solution: Increasing the frequency of inspections for seals and the maintenance efforts to retain them can stem leaks. In case leakage is established, countryside attendant personnel should refill the gas and inspect the affected component.
b) Contamination of SF₆ Gas: Moisture or other impurities contaminating SF₆ gas can reduce insulation properties and cause failures in the system.
- Solution: Contamination can be removed by purifying SF₆ gas with the help of filters. Impurities can be detected early through regular gas testing.
c) Insulation Breakdown: Partial discharge along with internal component damage may be caused by defects or ageing of the insulation materials.
- Solution: Insulation issues need to be employed with regular testing for partial discharge. Worn-out components should be replaced to avoid failure.
d) Mechanical Failures: Wear and tear as well as mechanical defects can cause issues with circuit gas insulated breakers and switches leading to mechanical failures.
- Solution: Routine maintenance along with scheduled preventive maintenance can detect issues early and have parts changed before failure occurs.
e) Temperature Fluctuations: Temperature changes greatly affect GIS performance as it can lead to the expansion and contraction of its materials.
- Solution: Ensure stable performance by providing cooling systems and temperature monitoring systems.
f) Corrosion: System integrity can be affected by moisture or pollutants.
- Solution: GIS should be installed in dry and clean environments to reduce risk. Regular inspections and protective coatings can also aid in preventing corrosion.
By following the preventive measures, GIS systems reduce failures and ensure longevity while remaining reliable and operational. So overall, regular maintenance is essential to achieve optimal performance.
8) Eberry Gas Insulated Switchgear Manufacturer
Eberry remains a dependable gas-insulated switchgear (GIS) manufacturer that provides sophisticated technologies for power distribution systems. Our systems are best fit for high standards of reliability, performance, and compactness for numerous uses.
- Compact Design: Eberry enables urban and underground gas substations to achieve maximum space utilization with the best gas-insulated switchgear (GIS) systems, thus making installation space-efficient.
- Ease of Maintenance: Eberry specializes in custom GIS systems that are tailored to meet the precise specifications provided by the clients. Thus, it makes it easier to serve different sectors and make our products user-friendly.
- Durability: Long-term sustainability and low maintenance are achievable with Eberry’s gas-insulated switchgear systems due to their durability in drastic conditions and resistance to wear and tear. Thus, providing consistent performance over time.
- High Performance: Dependable power distribution under severe conditions is possible with high-efficiency Eberry switchgear solutions that enhance operational efficacy.
- Reliability: Gas-insulated Eberry switchgear provides elevated ergonomics, safety and performance. Eberry is highly trusted by industrial clients and utility service providers across the globe.
9) FAQ
1. What is the difference between SF6 and GIS?
SF6 remains a dielectric gas for GIS, which is a complete switchgear system. It utilizes SF6 in Compact, Safe, and efficient Power distribution.
2. What is the lifespan of the GIS?
The lifespan of GIS is usually between 30 to 40 years with appropriate maintenance and under optimal Operating conditions, environment, and weather.
3. What are the key factors to consider when choosing a GIS?
While opting for a GIS, choose based on Space, Environment, Maintenance, performance needs, and budget to ensure maximum functionality and optimal costs.
