Abstract: As a pivotal international standard governing high-voltage electrical equipment, IEC 62271-203:2022 specifies comprehensive requirements for AC gas-insulated metal-enclosed switchgear (GIS) with rated voltages above 52 kV. This third edition, which supersedes the 2011 version, introduces significant technical revisions aligned with the latest industry practices, environmental considerations, and performance demands. This article elaborates on the scope, core technical updates, key specifications, and industry implications of IEC 62271-203:2022, providing insights for engineers, manufacturers, and professionals involved in the design, testing, and operation of high-voltage power systems.

1. Introduction

High-voltage switchgear and controlgear are critical components in power generation, transmission, and distribution networks, responsible for ensuring system safety, reliability, and operational continuity. Gas-insulated metal-enclosed switchgear (GIS) has gained widespread adoption due to its compact design, low maintenance requirements, low operational noise, and suitability for confined spaces. To address the evolving technical landscape and environmental challenges, the International Electrotechnical Commission (IEC) released the third edition of IEC 62271-203 in 2022, titled “High-voltage switchgear and controlgear – Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above 52 kV”. This standard cancels and replaces the second edition (IEC 62271-203:2011) and constitutes a major technical revision, reflecting advancements in insulation technology, environmental protection, and system performance optimization.

IEC 62271-203:203 applies to GIS where insulation is achieved, at least partially, by insulating gases or gas mixtures other than atmospheric air. It covers both indoor and outdoor installations and is applicable to AC systems with service frequencies up to and including 60 Hz. The standard complements and amends relevant specifications for individual GIS components, establishing a unified framework for the design, testing, and operation of high-voltage GIS systems globally.

2. Core Technical Revisions Compared to the 2011 Edition

IEC 62271-203:2022 introduces several significant technical changes to address emerging industry needs, including alignment with updated parent standards, environmental sustainability, and enhanced performance requirements. The key revisions are as follows:

2.1 Alignment with IEC 62271-1:2017

A fundamental update in the 2022 edition is its full alignment with IEC 62271-1:2017, the common specification for AC high-voltage switchgear and controlgear. This alignment ensures consistency across the IEC 62271 series, streamlining design and testing processes for manufacturers and facilitating global compliance. By harmonizing with the latest common specifications, the standard enhances interoperability between different components of high-voltage power systems.

2.2 Integration of Alternative Gases to SF₆

In response to global environmental concerns, the 2022 edition incorporates provisions for alternative gases alongside sulfur hexafluoride (SF₆) where necessary. SF₆ is a potent greenhouse gas with a high global warming potential (GWP), and the industry has been actively seeking low-GWP alternatives. The inclusion of alternative gases in the standard reflects the IEC’s commitment to promoting environmentally sustainable practices in high-voltage equipment design and operation.

2.3 Updated Terms and Definitions

The standard has undergone a comprehensive review of terms and definitions, updating existing terminology and removing unused terms. This revision enhances clarity and precision, reducing ambiguity in the interpretation and application of the standard. Clear terminology is essential for effective communication among international stakeholders, including manufacturers, test laboratories, and utility companies.

2.4 Enhanced Gas and Vacuum Tightness Requirements

Subclause 6.16 on “Gas and vacuum tightness” has been significantly updated, with a key revision in Subclause 6.16.3 (“Closed pressure systems”): the introduction of two gas classes based on GWP: GWP ≤ 1000 and GWP > 1000. For gases with GWP > 1000 (such as SF₆), the type test tightness requirement has been tightened from 0.5% to 0.1% per year per gas compartment. This stricter requirement minimizes the leakage of high-GWP gases, reducing environmental impact and improving the long-term reliability of GIS systems.

2.5 Defined Interface Pressure Requirements

Subclause 6.108 (“Interfaces”) now defines typical maximum operating pressures for interfaces connected to GIS. This specification provides clear guidance for the design and integration of GIS with other system components, ensuring compatibility and safe operation under various operating conditions.

2.6 Restructured and Updated Testing Provisions

Subclauses 7.102 through 7.108 have been restructured to improve logical flow and clarity. Additionally, Subclause 7.107 (“Corrosion test on earthing connections”) and Subclause 7.108 (“Corrosion tests on sealing systems of enclosures and auxiliary equipment”) have been updated to address corrosion challenges in different operating environments, enhancing the durability and lifespan of GIS equipment.

2.7 Modified Service Continuity Requirements

Annex F (“Service continuity”) has been modified and aligned with the recommendations of CIGRE Working Group B3.51. This update provides improved guidance for maintaining service continuity during GIS maintenance, repair, and extension, minimizing downtime and enhancing the reliability of power supply.

3. Key Technical Specifications and Application Scope

3.1 Technical Specifications

IEC 62271-203:2022 specifies detailed requirements for GIS design, construction, testing, and operation. Key technical specifications include:

• Rated voltage: Above 52 kV AC;
• Service frequency: Up to and including 60 Hz;
• Insulation medium: Insulating gases or gas mixtures (excluding atmospheric air), including SF₆ and alternative low-GWP gases;
• Installation environment: Indoor and outdoor;
• Tightness requirement: 0.1% per year per gas compartment for high-GWP gases (GWP > 1000);
• Corrosion resistance: Updated test requirements for earthing connections and sealing systems;
• Service continuity: Aligned with CIGRE WG B3.51 recommendations for maintenance and extension activities.

3.2 Application Scope

The standard is widely applicable to various high-voltage power system scenarios, including power generation plants, transmission and distribution networks, industrial facilities, and renewable energy installations (such as solar and wind power projects). Compliance with IEC 62271-203:2022 ensures that GIS systems meet international safety, reliability, and environmental standards, making it a critical reference for international projects and collaborations.

4. Industry Implications and Significance

IEC 62271-203:2022 plays a pivotal role in shaping the development of the high-voltage switchgear industry. Its key implications include:

4.1 Promoting Environmental Sustainability

By integrating alternative gases to SF₆ and tightening tightness requirements for high-GWP gases, the standard drives the industry toward more environmentally friendly solutions. This aligns with global efforts to reduce greenhouse gas emissions and combat climate change, encouraging manufacturers to invest in the research and development of low-GWP insulation gases and leak-tight designs.

4.2 Enhancing System Reliability and Safety

The updated testing provisions, corrosion resistance requirements, and service continuity guidelines improve the overall reliability and safety of GIS systems. Stricter tightness requirements minimize gas leakage, reducing the risk of insulation failure and system breakdown. Updated corrosion tests ensure that GIS equipment can withstand harsh operating environments, extending its lifespan and reducing maintenance costs.

4.3 Facilitating Global Standardization

As an international standard, IEC 62271-203:2022 promotes global harmonization of GIS design, testing, and operation requirements. This facilitates international trade, collaboration, and knowledge sharing, enabling manufacturers to develop products that meet the needs of global markets. For utility companies and project managers, compliance with the standard ensures that equipment from different suppliers is interoperable, simplifying system integration and reducing project risks.

4.4 Supporting Renewable Energy Integration

With the growing adoption of renewable energy sources, high-voltage power systems require reliable and efficient switchgear to integrate variable renewable generation into the grid. IEC 62271-203:2022 provides a robust framework for the design and operation of GIS systems used in renewable energy installations, ensuring grid stability and reliability as the energy mix transitions toward sustainability.

IEC 62271-203:2022 represents a significant advancement in the standardization of high-voltage AC gas-insulated metal-enclosed switchgear. By incorporating the latest technical developments, environmental considerations, and industry best practices, this third edition provides a comprehensive and unified framework for the design, testing, and operation of GIS systems with rated voltages above 52 kV. The key revisions, including the integration of alternative gases, tightened tightness requirements, and updated testing provisions, drive the industry toward greater sustainability, reliability, and safety.

For professionals in the high-voltage power industry, understanding and complying with IEC 62271-203:2022 is essential to developing and deploying high-performance, environmentally friendly GIS systems. As the industry continues to evolve, the standard will play a crucial role in supporting the transition to a more sustainable and reliable power system.

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] IEC. (2022). Performance and safety requirements for gas-insulated switchgear. IEC Blog, 15 June 2022.

[3] European Standards. (2024). BS EN IEC 62271-203:2022 High-voltage switchgear and controlgear – AC gas-insulated metal-enclosed switchgear for rated voltages above 52 kV.

[4] CLC. (2022). EN IEC 62271-203:2022 High-voltage switchgear and controlgear – Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above 52 kV. standards.iteh.ai.

[5] DIN Media. (2023). DIN EN IEC 62271-203:2023-04 High-voltage switchgear and controlgear – Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above 52 kV.