Electrical distribution and safety are critical for industries, commercial buildings, and infrastructure projects. Air Insulated Switchgear (AIS) is one of the most commonly used technologies for power distribution, offering an economical and reliable energy distribution system for both medium and high voltage.

This article delves into what air-insulated switchgear is, its features, types, working principles, components, and benefits.

An Overview of Air-Insulated Switchgear

Air-insulated switchgear (AIS) is a type of switchgear that makes use of air as the main insulating medium for electrical components. Because of its cost-effectiveness and ease of maintenance, it is widely used in substations, power plants, and industrial applications.

AIS includes circuit breakers, disconnectors, current transformers, voltage transformers, and other such elements assembled in metal-clad enclosures or open-type structures. The use of air as the insulating medium ensures that AIS is environmentally friendly and simple to operate, in contrast with gas-insulated switchgear (GIS), in which SF6 gas is used.

AIS is used in high-reliability applications with easy access for servicing. Its relatively low installation cost and flexible operation make it the option of choice for medium-voltage (MV) and high-voltage (HV) power distribution systems.

Features of AIS

AIS is a trustworthy and efficient solution for different electrical applications with its various features. Here are some key features:

- Air Insulation: Instead of SF6 gas, atmospheric air is used as the insulating medium.

- Open & Compact Designs: Offered in open or metal-clad options.

- Affordable: It has lower capital and maintenance costs compared to gas-insulated switchgear.

- Simple Maintenance: The parts are easily reachable for checkups, testing, and repairs.

- High Safety Standards: The series is designed with safety interlocks and protective measures.

- Flexible Configurations: These are available for indoor and outdoor installations in various environmental situations.

- Scalable: The network is extensible and adjustable as the needs of the system grow.

- Durability: Engineered for rugged environments and operational realities.

Hence, AIS is widely used in power distribution and industrial applications.

How Does AIS Work?

AIS working principles revolve around the concept of air as an insulating entity used to separate electrical faults. The essential elements of AIS are circuit breakers, busbars, disconnectors, and transformers within metal structures or open-air systems.

In the event of a fault in the electrical system, the circuit breaker stops the flow of current to protect the network. AIS uses air gaps between live parts for insulation. This avoids electrical breakdown and guarantees smooth operation.

It ensures that the negative impact on the power plant due to weaknesses does not affect the supply of electricity. It has a comparatively larger space requirement than gas-insulated switchgear (GIS) equipment but is easy to maintain and inspect thanks to its air-insulated nature.

Types of AIS

AIS is also classified into several types based on application and rating. The main categories include:

1. Low-Voltage AIS (Up to 1kV)

- Application Commercial Buildings, Residential Complexes, and Small Industries

- Encompasses LV circuit breakers, busbars, and switchgear.

2. 1kV to 36kV Medium-Voltage AIS

- Widely used in industrial plants, distribution networks, and substations.

- Covers vacuum circuit breakers, disconnectors, and protective relays.

3. High-Voltage AIS (Above 36kV)

- Utilized in transmission and power generation substations.

- High insulation requirements require large clearances between live parts.

Different AIS are configured to serve different voltage levels and operational needs.

Switchgear Components: Air Insulated

The main components of air-insulated switchgear are:

- Circuit Breakers: When a fault occurs, this breaks the current.

- Busbars: Transport electrical power between various components.

- Disconnectors (Isolators): Used to isolate portions of the system for maintenance.

- Current Transformers (CTs): Measure electrical current and provide data for protection and monitoring.

- Voltage Transformers (VTs): Trace system voltage and safeguard by limiting overvoltage conditions.

- Machine Learning: To detect anomalies in human/physical resources.

- Earthing Switches: Grounding is necessary to avoid unwanted electrical flow.

- Control Panels: In charge of operating and monitoring the switchgear system.

These components work in harmony to provide proper and effective power distribution.

Advantages of Air-Insulated Switchgear

Air-insulated switchgear has multiple advantages that contribute to its common usage in numerous applications:

1. Cost-Effectiveness

• AIS is more economical than Gas Insulated Switchgear (GIS).

• Reduced initial investment and upkeep costs.

2. Simple to Operate and Maintain

• Any part can be inspected, tested, and repaired. No special gas handling equipment is needed.

3. Environmentally Friendly

• Uses natural air as an insulation medium. No SF6 gas is required.

• Lower carbon footprint compared to gas-insulated switchgear.

4. High Reliability and Safety

• Accidental startup prevention with safety interlocks and preventive measures against electric shocks.

• Effective insulator and fault protection.

5. Scalability and Flexibility

• The power grid can be gradually increased or adjusted to fulfill the needs of the future.

• Appropriate for interior and exterior installations.

6. Proven Technology

• AIS has been used for years and is a recognized, proven technology for power distribution.

These benefits make AIS a solution of choice for power utilities, industries, and infrastructure projects.

Applications of Air Insulated Switchgear

AIS is widely used in various sectors due to its cost efficiency and easy maintenance. Some of the key applications of AIS include:

1. 1. Power Generation Plants: Used in substations to manage power transmission.

2. 2. Industrial Facilities: Ensures smooth operation of heavy machinery and production lines.

3. 3. Commercial Buildings: Provides safe and efficient power distribution boards in offices and shopping malls.

4. 4. Transportation Infrastructure: Used in railway stations, airports, and metros for power management.

5. 5. Renewable Energy Projects: Helps integrate solar and wind power into the electrical grid.

6. 6. Utilities and Distribution Networks: Used by power companies for medium and high-voltage distribution.

These applications highlight the versatility and reliability of AIS across different industries.

Also Read:  Electrical Switchgear? Types, Functions & Applications

Conclusion

Air Insulated Switchgear (AIS) is a dependable and economical option for distributing medium and high-voltage power. By using air as the insulation medium, it is a sustainable and low-maintenance alternative to gas-insulated systems. Due to high safety, scalability, and easy operation, AIS remains the preferred choice of many industries.

AIS enables efficient, safe, and durable power management solutions across a variety of applications, industrial plants, power distribution networks, and substations.