What is medium voltage switchgear?

Medium voltage (MV) switchgear is power equipment that controls, protects and switches alternating current (AC) systems with voltages ranging from 1 kV to 52 kV. This technology is used at industrial facilities, power generation plants, renewable energy systems and inside commercial buildings.

TGOOD Australia sells both primary and secondary MV switchgear, including Brunstock’s range of SF6-free GIS (gas insulated switchgear). Secondary GIS is also sometimes called an RMU or ring main unit, whereas we refer to primary GIS as switchboards.

All types of switchgear can be installed in appropriate kiosks or e-houses (also called switchrooms, step-up stations, collector stations or substations) according to project specifications. This makes our GIS products ‘indoor GIS’ or ‘metal enclosed switchgear’.

What is MV switchgear used for?

Power distribution: Ensuring that power is distributed evenly
Energy management: Managing energy efficiently
Equipment function: Ensuring that equipment functions smoothly during energy fluctuations
System stability: Stabilising important functions like machine control, design, operations, and maintenance
System protection: Cutting the current in case of a short circuit or sudden current increase

MV switchgear is a critical component in Australia’s electrical distribution network, ensuring the safe and efficient management of electrical power. In Australia, MV switchgear is widely used across various sectors, including industrial, commercial and utility applications. This article explores the common types of MV switchgear used in Australia and their applications.

Types of MV switchgear

Air-insulated switchgear (AIS)

Description: AIS uses air as the primary insulating medium. It is known for its simplicity, reliability, and ease of maintenance.
Applications: Commonly used in industrial plants, commercial buildings and utility substations.
Examples: TGOOD’s TAP 17

Gas-insulated switchgear (GIS)

SF6 GIS

Description: GIS uses sulfur hexafluoride (SF6) gas as the insulating medium, which allows for a more compact design compared to AIS.
Applications: Ideal for urban areas and indoor installations where space is limited.
Examples: TGOOD’s TGP 40.5, TGS 12, TGS 24 and TGS 40.5, which contain SF6

SF6-free GIS

Description: SF6-free GIS uses compressed dry air as the insulating gas. This modernisation of GIS technology supports the same compact design without the greenhouse gas risk posed by SF6. This is an environmentally friendly option and with TGOOD it does not need to cost more.
Applications: Ideal for renewable energy plants and indoor installations where space is limited, as well as for any project where a reduced carbon footprint is desired throughout the lifecycle of the switchgear collector station.
Examples: Brunstock’s BGP 40.5, BGS 12 and BGS 40.5, which are SF6-free

What is inside medium voltage switchgear?

The structure of the medium voltage GIS depends on its application at the final project site. Our TGS (TGOOD Gas-insulated Secondary switchgear) is often manufactured in a CCV layout with two switch panels and a breaker panel, as the following image depicts.

Some components of MV switchgear include: circuit breakers, disconnector switches, protection relays, a voltage transformer (VT) and current transformers (CTs).

Below is a view inside a TGOOD secondary gas insulated switchgear unit. You can see the switchgear and protection relays, however the circuit breaker is inside and the VT and CTs have not yet been installed in the bottom compartment. The diagram beneath it depicts all of the technology found in this MV switchgear.

Features and benefits of MV GIS

Safety: MV switchgear in Australia is designed with advanced safety features, including arc flash protection and condition monitoring sensors, to ensure the safety of personnel and equipment.

Reliability: High-quality MV GIS ensures reliable operation, minimising downtime and maintenance costs.

Sustainability: Modern MV switchgear incorporates eco-friendly technologies, such as SF6-free insulation and digital monitoring, to reduce environmental impacts.

Where and how is switchgear installed?

Switchgear is often installed inside a building called a kiosk or an e-house. A kiosk substation is an electrical kiosk that looks like a metal container or donga. TGOOD makes both the switchroom buildings (e-houses and kiosks) and the switchgear that is installed inside them. Designed by electrical engineers and installed by licensed electricians, TGOOD transformer kiosks contain transmission and distribution equipment necessary for the final project site.

Both kiosks and e-houses are made of steel and can be as big as a 20-foot shipping container, or larger. An e-house is much larger than a kiosk and typically involves a concrete pad, metal support structures and a staircase leading up to it. E-houses are raised up from the ground to ensure the electrical equipment inside is protected from natural disasters like bushfires, floods, dust and pests.

TGOOD Australia has installed e-houses in Western Downs, Warwick, Longreach, Haughton, Emerald, Oakey (QLD) and Tailem Bend (SA). These e-houses contain switchgear, protection relays, LV panels and more.

Switchgear quality standards

TGOOD switchgear complies with applicable IEC standards, including IEC 62271-200 Switchgear and controlgear, 62271-102 disconnector and earthing switch and 62271-103 Switches.

Applications in Australia

Industrial Sector: MV switchgear is used to manage power distribution in manufacturing plants, mining operations, and processing facilities.
Commercial Buildings: MV GIS ensures efficient power distribution in large commercial complexes, hospitals and data centres.
Utility Sector: Switchgear is essential for the distribution of electricity in urban and rural areas, ensuring a stable and reliable power supply.

Conclusion

MV switchgear plays a vital role in Australia’s electrical infrastructure, providing safe, reliable and sustainable power distribution solutions. With advancements in technology, MV switchgear continues to evolve, offering enhanced performance and reduced environmental impact.

If you want to buy MV switchgear for your project, simply contact TGOOD Australia with the details of your tender. We would be delighted to submit our offer and customise just the right switchgear for your site. Best of all, TGOOD offers high quality workmanship, speedy delivery and a competitive price.

For more detailed information on specific products and technical specifications, please refer to the downloads and articles listed at the end of our MV switchgear offer page.

If you would like further information please contact our sales team:

• Email: australia@tgood.com
• Phone (AU): 1300 061 299