What is air-insulated switchgear(ais)？

Air Insulated Switchgear (AIS) is a crucial component of high voltage switchgear that utilizes air as the insulation medium for the busbars and circuit breakers. Its widespread use in power distribution systems underscores its reliability, safety, and cost-effectiveness. This comprehensive introduction delves into the definition, product features, working principle, technical parameters, internal components, structure, application, installation, advantages, differences, similarities with Gas Insulated Switchgear (GIS), maintenance, and more, all of which are vital for understanding its role in power distribution systems.

Definition:

Air Insulated Switchgear (AIS) is a type of switchgear that relies on air as the primary insulation medium for the busbars and circuit breakers. Its primary function is to control, protect, and isolate electrical equipment in high voltage power systems, thereby playing a crucial role in ensuring the safe and reliable operation of electrical power systems. AIS is a common sight in substations and power distribution networks, where its presence is a testament to its importance in maintaining the integrity of electrical power systems.

Product Features:

• Robust and reliable design
• Cost-effective insulation medium
• Easy to install and maintain
• Suitable for outdoor and indoor applications
• High level of safety for personnel and equipment
• Modular design for flexibility and scalability
• Environmentally friendly due to the use of air as the insulation medium

Working Principle:

The working principle of AIS is centered around the use of air as the primary insulation medium, which is instrumental in isolating and controlling the flow of electrical current. The switchgear is designed to withstand high voltage and current levels, ensuring the safety and reliability of the electrical system. In the event of a fault, the circuit breakers within the AIS are primed to interrupt the current flow and isolate the faulty section of the system, thereby preventing further damage and ensuring the system's continued operation.

Technical Parameters:

The technical parameters of AIS include voltage rating, current rating, short-circuit withstand capability, insulation level, and environmental conditions. The voltage rating typically ranges from 3.6 kV to 36 kV, with higher voltage ratings available for specific applications. The current rating is determined based on the load requirements and system capacity. Short-circuit withstand capability is an important parameter that ensures the switchgear can withstand high fault currents without damage. The insulation level is specified to ensure the safety and reliability of the system under normal and fault conditions. Environmental conditions such as temperature, humidity, and altitude also play a crucial role in determining the suitability of AIS for a particular application.

Internal Components:

• The internal components of AIS include circuit breakers, disconnectors, busbars, current transformers, voltage transformers, and control and protection devices. 
• The circuit breakers are designed to interrupt the current flow in the event of a fault or during maintenance operations. 
• Disconnectors are used to isolate the equipment for maintenance or repair. 
• Busbars provide the main electrical connections within the switchgear. 
• Current transformers and voltage transformers are used for metering and protection purposes. 
• Control and protection devices ensure the safe and reliable operation of the switchgear.

Structure:

• The structure of AIS typically consists of metal enclosures, busbars, circuit breakers, disconnectors, and control panels. 
• The metal enclosures provide protection for the internal components and ensure the safety of personnel. 
• Busbars are used to connect the incoming and outgoing electrical circuits. 
• Circuit breakers and disconnectors are mounted within the enclosure to control the flow of electrical current. 
• Control panels house the control and protection devices for monitoring and operating the switchgear.

Application:

AIS is widely used in power distribution systems, including substations, industrial plants, commercial buildings, and utility networks. It is suitable for both indoor and outdoor applications and can be customized to meet specific requirements. AIS is commonly used in medium voltage applications, typically ranging from 3.6 kV to 36 kV, although higher voltage ratings are available for specialized applications. It is an essential component of the electrical infrastructure that ensures the safe and reliable distribution of electrical power.

Installation:

The installation of AIS involves careful planning, site preparation, equipment assembly, and testing. The switchgear is typically installed in a dedicated area within a substation or a power distribution facility. The installation process includes:Mounting the switchgear.Connecting the electrical circuits.Testing the functionality of the equipment.Commissioning the system for operation.Proper installation is crucial to ensure the safety and reliability of the electrical system.

Advantages of AIS over GIS:

Cost-Effectiveness: AIS is generally more cost-effective to install and maintain compared to GIS due to the simpler design and use of air as the insulation medium.

Environmental Impact: AIS has a lower environmental impact compared to GIS, as it does not use SF6 gas, which is a potent greenhouse gas with a high global warming potential.

Maintenance: AIS typically requires less maintenance compared to GIS, thanks to its simpler design and the absence of complex gas monitoring and handling systems. This simplicity in maintenance should give you peace of mind in your work with AIS in power distribution systems. 

Flexibility: AIS offers greater flexibility in terms of expansion and modifications due to its modular design and ease of installation.

Differences between AIS and GIS:

Insulation Medium: AIS uses air as the insulation medium, while GIS uses SF6 gas or other insulating gases.

Size and Weight: GIS is generally more compact and lighter compared to AIS due to the use of gas insulation.

Installation and Maintenance: GIS requires specialized installation and maintenance procedures due to the use of gas insulation, while AIS is relatively simpler to install and maintain.

Environmental Impact: GIS has a higher environmental impact due to the use of SF6 gas, while AIS is considered more environmentally friendly.

Similarities between AIS and GIS:

Both AIS and GIS are used for high voltage applications in power distribution systems.

Both types of switchgear are designed to control, protect, and isolate electrical equipment in substations and power distribution networks.

Both AIS and GIS are essential components of the electrical infrastructure that ensure the safe and reliable distribution of electrical power.

Maintenance:

The maintenance of AIS involves regular inspections, testing, and preventive maintenance activities to ensure the safe and reliable operation of the switchgear. Maintenance tasks include visual inspections, electrical testing, mechanical checks, and cleaning of the equipment. It is important to follow the manufacturer's recommendations and industry standards for maintenance procedures to prolong the service life of the switchgear and minimize the risk of failures.

Conclusion

In conclusion, Air Insulated Switchgear (AIS) is a critical component of power distribution systems, providing reliable and cost-effective solutions for controlling and protecting electrical equipment. With its robust design, use of air as the insulation medium, and wide range of applications, AIS continues to be a preferred choice for high voltage switchgear installations. Understanding the features, working principle, technical parameters, internal components, structure, application, installation, advantages, differences, similarities with Gas Insulated Switchgear (GIS), and maintenance requirements of AIS is essential for ensuring the safe and efficient operation of power distribution systems.