By sion932 
With the continuous development of the power industry, the safety, reliability, and standardization of high-voltage switchgear and controlgear have become crucial to ensuring the stable operation of power grids. The International Electrotechnical Commission (IEC) released IEC 62271-200-2021 “High-voltage switchgear and controlgear – Part 200: AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV” in May 2021. As the third edition of this standard, it cancels and replaces the 2011 second edition, introducing significant technical revisions to adapt to the evolving needs of the industry. This article provides a detailed overview of the core content, key changes, and practical implications of IEC 62271-200-2021.
1. Scope and Application of the Standard
IEC 62271-200-2021 is specifically applicable to prefabricated AC metal-enclosed switchgear and controlgear assemblies, with clear界定 on the operating parameters and installation environments of the equipment. According to the standard, the covered equipment shall be designed for alternating current, with rated voltages ranging from above 1 kV to 52 kV inclusive, and service frequencies up to and including 60 Hz. Notably, the standard is applicable to both indoor and outdoor installation scenarios, demonstrating strong environmental adaptability. In terms of structural composition, the switchgear assemblies can include air-insulated and/or fluid-filled compartments, which covers the mainstream structural types of metal-enclosed switchgear in the current market.
It is worth emphasizing that this standard provides unified technical requirements for the entire lifecycle of the equipment, including design, manufacturing, installation, operation, and maintenance. It focuses on multiple aspects such as electrical performance, mechanical performance, environmental adaptability, and safety protection, aiming to ensure that the equipment can maintain stable and reliable operation under various working conditions. For components in metal-enclosed switchgear, this standard supplements or replaces the requirements in individual product standards in some cases, forming a comprehensive technical specification system.
2. Core Technical Requirements
IEC 62271-200-2021 specifies a series of key characteristic quantities and technical requirements to ensure the performance and safety of the equipment. The core technical requirements mainly include the following aspects:
2.1 Electrical Performance Requirements
The standard clearly defines the requirements for rated voltage (Ur), rated insulation level (Ud, Up, Us), rated frequency (fr), rated continuous current (Ir), rated short-time withstand currents (Ik, Ike), and rated peak withstand currents (Ip, Ipe). These parameters are the core indicators to measure the electrical performance of the switchgear. For example, the rated insulation level ensures that the equipment can withstand the impact of overvoltage during operation without insulation breakdown; the rated short-time withstand current and rated peak withstand current determine the equipment’s ability to withstand short-circuit faults, which is crucial to protecting the power grid and equipment itself.
In terms of resistance measurement of the main circuit, the standard adjusts the test requirements: resistance measurement is only required before the continuous current test as a reference for routine tests, and it is no longer needed after the continuous current test. This adjustment optimizes the test process on the premise of ensuring the reliability of the test results, improving the efficiency of product testing.
2.2 Mechanical Performance and Environmental Adaptability
The equipment shall have sufficient mechanical strength and stability to withstand the mechanical stress generated during operation, transportation, and installation. At the same time, it shall adapt to different environmental conditions, including high temperature, low temperature, humidity, vibration, and other harsh environments, ensuring normal operation without performance degradation. This requirement is particularly important for outdoor switchgear, which needs to resist the impact of various natural environments.
2.3 Safety Protection Requirements
Safety protection is a key part of the standard, which includes requirements for grounding protection, overcurrent protection, overvoltage protection, etc. The equipment shall be equipped with a complete grounding system to ensure the personal safety of operators; overcurrent and overvoltage protection devices shall accurately act when faults occur, cutting off the fault circuit in a timely manner to prevent the expansion of faults. In addition, the standard also puts forward relevant requirements for the safety of auxiliary and control circuits, including rated supply voltage (Ua) and rated supply frequency, to ensure the reliable operation of the control system.
3. Key Changes from the Previous Edition (2011 Edition)
As a technical revision edition, IEC 62271-200-2021 has made several significant changes compared with the 2011 second edition, mainly including the following aspects:
3.1 Alignment with IEC 62271-1:2017
The clause numbering of this edition is aligned with IEC 62271-1:2017, and the subclause names of clause 3 are adopted. This alignment ensures the consistency and coherence of the entire IEC 62271 series standards, facilitating the use and implementation of the standards by enterprises, testing institutions, and other relevant parties. It also promotes the unification of technical specifications in the field of high-voltage switchgear.
3.2 Adjustment of Internal Arc Testing Content
The internal arc testing on pole-mounted switchgear is removed from this standard, as it is now covered by the specific standard IEC 62271-214:2019. This adjustment realizes the refinement and specialization of the standard system, making each standard focus on a more specific field, which is conducive to improving the accuracy and pertinence of the standard requirements.
3.3 Optimization of Test Procedures
As mentioned earlier, the standard optimizes the resistance measurement procedure of the main circuit, canceling the resistance measurement after the continuous current test. This optimization not only reduces the test workload but also avoids the impact of the continuous current test on the resistance measurement results, improving the scientificity of the test.
4. Practical Significance and Application Prospects
IEC 62271-200-2021 plays an important guiding role in the production and application of AC metal-enclosed switchgear. For manufacturers, the standard provides clear technical specifications, guiding the design and manufacturing of products, improving product quality and reliability. For users, the standard provides a reliable basis for the selection, installation, and maintenance of equipment, ensuring the safe and stable operation of the power grid.
With the global promotion and implementation of this standard, it will help to unify the technical standards of AC metal-enclosed switchgear in different countries and regions, promoting the international circulation of products. At the same time, the standard’s emphasis on safety, reliability, and environmental adaptability is consistent with the development trend of the modern power industry, which is conducive to promoting the technological progress and upgrading of the industry.
In addition, the 2024 amendment (AMD 1:2024) of IEC 62271-200-2021 further improves and supplements the standard, adjusting the relevant clauses in sections 6 to 9 and adding Appendix E. This continuous revision ensures that the standard can keep pace with the development of the industry, adapting to the new technical requirements and application scenarios.
IEC 62271-200-2021, as the latest international standard for AC metal-enclosed switchgear and controlgear, integrates the advanced experience and technical achievements in the industry. Its release and implementation are of great significance to improving the standardization level of the power industry, ensuring the safe and reliable operation of the power grid, and promoting international technical exchanges and cooperation. Enterprises and relevant institutions in the power industry should actively study and implement this standard, continuously improve the quality and technical level of products, and contribute to the high-quality development of the global power industry.