By sion932 
With the continuous evolution of power systems towards higher voltage levels, greater reliability, and enhanced environmental sustainability, the International Electrotechnical Commission (IEC) has released the third edition of IEC 62271-203:2022, a pivotal standard governing high-voltage switchgear and controlgear. Specifically focused on AC gas-insulated metal-enclosed switchgear (GIS) for rated voltages above 52 kV, this standard represents a significant technical revision that supersedes the 2011 second edition. It aligns with the latest industry practices, addresses environmental concerns, and refines performance and safety requirements, thereby playing a crucial role in guiding the design, manufacturing, testing, and operation of GIS equipment globally.
1. Scope and Core Definition of IEC 62271-203:2022
IEC 62271-203:203 specifies comprehensive requirements for gas-insulated metal-enclosed switchgear where insulation is achieved, at least in part, by an insulating gas or gas mixture other than atmospheric air. The standard applies to equipment designed for alternating current (AC) applications with rated voltages exceeding 52 kV, suitable for both indoor and outdoor installations, and compatible with service frequencies up to and including 60 Hz <superscript>1<superscript>4. For the purposes of this standard, the terms “GIS” and “switchgear” are used interchangeably to refer to gas-insulated metal-enclosed switchgear, which consists of individual components intended for direct interconnection and operation as an integrated system <superscript>5. Notably, the standard complements and amends relevant specifications for individual GIS components, ensuring a holistic approach to system-level performance and safety.
2. Key Technical Revisions Compared to the 2011 Edition
The 2022 edition of IEC 62271-203 introduces several critical technical changes, driven by the need to align with updated industry standards, address environmental challenges, and improve operational reliability. The most significant revisions include the following:
2.1 Alignment with IEC 62271-1:2017
A fundamental update is the alignment of IEC 62271-203:2022 with IEC 62271-1:2017, the common specification for AC high-voltage switchgear and controlgear <superscript>4. This alignment ensures consistency across the IEC 62271 series, facilitating interoperability between different components and simplifying compliance for manufacturers and end-users.
2.2 Integration of Alternative Gases to SF₆
In response to global concerns about climate change, the standard now incorporates alternative insulating gases alongside sulfur hexafluoride (SF₆) where appropriate <superscript>1<superscript>4. SF₆, while an excellent insulating gas, has a very high global warming potential (GWP). The inclusion of alternative gases reflects the industry’s shift towards more environmentally sustainable solutions, supporting global efforts to reduce greenhouse gas emissions.
2.3 Updated Terms and Definitions
The standard has undergone a comprehensive review of terms and definitions, with outdated or unused terms removed and new ones added to reflect current industry terminology and practices <superscript>1<superscript>7. This refinement enhances clarity and reduces ambiguity, ensuring consistent interpretation and application of the standard worldwide.
2.4 Enhanced Gas Tightness Requirements
Subclause 6.16 on “Gas and Vacuum Tightness” has been substantially updated. A key change is the introduction of two gas classes based on GWP: GWP ≤ 1000 and GWP > 1000 <superscript>1<superscript>7. For gases with GWP > 1000 (such as SF₆), the tightness requirement for type tests has been tightened from 0.5% to 0.1% per year per gas compartment <superscript>1<superscript>4. This stricter requirement minimizes the leakage of high-GWP gases, further reinforcing environmental protection.
2.5 Defined Interface Pressure Specifications
Subclause 6.108 on “Interfaces” now defines typical maximum operating pressures for interfaces connected to GIS <superscript>1<superscript>7. This specification provides clear guidance for system integration, ensuring compatibility between GIS and other connected equipment and reducing the risk of pressure-related failures.
2.6 Restructured and Updated Corrosion Test Requirements
Subclauses 7.102 through 7.108 have been restructured for better logical flow. Additionally, subclauses 7.107 (“Corrosion Test on Earthing Connections”) and 7.108 (“Corrosion Tests on Sealing Systems of Enclosures and Auxiliary Equipment”) have been updated to reflect advancements in corrosion protection technologies and to address the challenges of harsh operating environments <superscript>1<superscript>4. These updates ensure that GIS equipment maintains reliable performance over its service life, even in corrosive conditions.
2.7 Modified Service Continuity Guidelines
Annex F on “Service Continuity” has been revised and aligned with the recommendations of CIGRE Working Group B3.51 <superscript>1<superscript>7. This modification provides improved guidance on maintaining service continuity during GIS maintenance, repair, and extension, helping utilities and operators minimize downtime and ensure reliable power supply to end-users.
3. Applications and Industry Significance
IEC 62271-203:2022 is widely applicable across key sectors of the power industry, including power generation plants, transmission and distribution networks, industrial facilities, and renewable energy installations <superscript>3. GIS equipment compliant with this standard offers numerous advantages, such as compact size, high reliability, and suitability for both indoor and outdoor use, making it an essential component in modern power systems.
For industry professionals—including engineers, project managers, and procurement specialists—this standard serves as an invaluable resource. It provides a robust framework for ensuring that GIS equipment meets the highest safety, performance, and environmental standards <superscript>3. By adhering to IEC 62271-203:2022, organizations can minimize the risk of equipment failures, enhance system reliability, and support sustainable energy development.
IEC 62271-203:2022 represents a significant step forward in the standardization of high-voltage AC GIS equipment. Its key technical revisions, including the integration of alternative gases, stricter environmental requirements, and enhanced performance specifications, reflect the industry’s commitment to reliability, safety, and sustainability. As the global power sector continues to grow and evolve, compliance with this standard will be essential for manufacturers, utilities, and operators to ensure the safe, efficient, and environmentally responsible operation of high-voltage power systems. The availability of a commented version (CMV) of the standard further facilitates its implementation by highlighting changes from the previous edition and providing expert insights into the reasoning behind these updates <superscript>4.
References
[1] IEC. (2022). IEC 62271-203:2022 High-voltage switchgear and controlgear – Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above 52 kV. IEC Webstore.
[2] European Standards. (2024). BS EN IEC 62271-203:2022 High-voltage switchgear and controlgear. EN-Standard.eu.
[3] IEC. (2022). Performance and safety requirements for gas-insulated switchgear. IEC.ch.
[4] Accuris Standards Store. (2022). IEC 62271-203 Ed. 3.0 b:2022 Gas-insulated metal-enclosed switchgear for rated voltages above 52 kV.
[5] KSSN. (2022). IEC 62271-203:2022 Detailed Information. intra.kssn.net.