By sion932 
As a core national standard in China’s power transformer industry, GB 1094.1-2013 <Power transformers—Part 1: General> plays a pivotal role in regulating the design, manufacturing, inspection, and testing of power transformers. Issued on December 17, 2013, and implemented on December 14, 2014, this standard replaces the previous version GB 1094.1-1996, incorporating advanced international technical requirements while adapting to China’s specific power grid environment and industrial practices. This article provides a comprehensive technical overview of GB 1094.1-2013, focusing on its scope, key technical provisions, relationship with international standards, and industrial significance.
1. Scope of Application
GB 1094.1-2013 specifies the general technical requirements for three-phase and single-phase power transformers, including autotransformers. However, it excludes certain small and special types of transformers, which are clearly defined as follows:
- Single-phase transformers with a rated capacity of less than 1 kVA and three-phase transformers with a rated capacity of less than 5 kVA;
- Transformers where all windings have a rated voltage not exceeding 1000 V;
- Instrument transformers, traction transformers for rolling stock, starting transformers, testing transformers, and welding transformers;
- Explosion-proof mining transformers and deep-water (submerged) application transformers.
It should be noted that for certain types of industrial special transformers without corresponding specific standards (especially those with all windings voltage not higher than 1000 V), this standard can be applied in whole or in part. Additionally, the standard does not cover the requirements for transformers installed in public places.
2. Key Technical Provisions
The technical content of GB 1094.1-2013 is structured into 13 main chapters and 9 appendices (including normative and informative appendices), covering essential aspects from basic definitions to safety requirements. The core technical provisions are summarized as follows:
2.1 Terms and Definitions
Compared with the previous version, the standard adds the definition of harmonic content, which is crucial for adapting to the increasing harmonic pollution in modern power grids and ensuring the stable operation of transformers under non-sinusoidal voltage and current conditions.
2.2 Service Conditions and Rated Values
Chapter 4 of the standard specifies the service conditions of transformers, including environmental temperature, humidity, altitude, and other climatic and mechanical conditions. Chapter 5 defines key rated values such as rated capacity, rated frequency, and rated voltage, which are the fundamental basis for transformer design and application. The standard also puts forward general requirements for the selection of transformer materials and structural design, emphasizing mechanical and electrical rationality, as well as convenience for manufacturing, transportation, installation, and maintenance.
2.3 Tap Windings, Connections, and Nameplates
For transformers with tap windings, the standard details the requirements for tap adjustment methods, voltage regulation ranges, and functional specifications, providing examples of mixed voltage regulation and high/low-voltage regulation technical specifications in Appendix E. In terms of connections, it adds the connection group labeling for single-phase transformers, supplementing the previous lack of relevant provisions. Chapter 8 specifies the content and format of transformer nameplates, ensuring that key technical parameters are clearly marked for easy operation and maintenance.
2.4 Safety, Environmental, and Test Requirements
Safety and environmental requirements are important additions to this standard, including provisions on short-circuit strength, insulation strength, thermal stability, and mechanical strength to ensure transformer reliability under various operating conditions. It also adds requirements for liquid protection systems and DC current in neutral lines, addressing potential safety hazards in practical operation. In terms of testing, the standard adjusts the test items and adds new tests such as pressure tightness test, vacuum deformation test, and on-site vacuum tightness test for liquid-immersed transformers, further improving the quality control of transformers.
2.5 Electromagnetic Compatibility (EMC) and High-Frequency Transients
Chapters 12 and 13 focus on EMC and high-frequency operation transients, specifying the electromagnetic interference limits and anti-interference requirements of transformers, which helps to reduce the impact of transformers on the power grid and surrounding electronic equipment and improve the overall stability of the power system.
3. Relationship with International Standards
GB 1094.1-2013 adopts a modified re-drafting method to adopt IEC 60076-1:2011 <Power transformers—Part 1: General> (MOD), maintaining consistency with international advanced standards while making localized modifications to adapt to China’s national conditions. These technical differences are identified by vertical single lines in the margin of the standard, and Appendix A provides a detailed list of differences and their reasons.
For example, considering the characteristics of China’s power grid (such as large voltage fluctuations in some regions and frequent thunderstorms in certain areas), the standard adjusts some test parameters and adds design requirements suitable for China’s special climatic conditions. In addition, the standard makes editorial modifications to the international standard, such as merging multiple figures, adjusting table structures, and reclassifying appendices, to improve readability and applicability.
4. Industrial Significance and Impact
As the fundamental general standard in the GB 1094 series, GB 1094.1-2013 provides unified technical criteria for manufacturers, inspection institutions, and purchasers in the power transformer industry, ensuring the consistency of product quality and performance. The addition of new technical requirements (such as state monitoring equipment reserved interfaces in Appendix H and environmental and safety factors in Appendix I) promotes the technological progress of the industry, guiding enterprises to develop in the direction of intelligence, environmental protection, and safety.
Since its implementation, the standard has effectively improved the reliability and safety of power transformers in China, reduced equipment failure rates, and provided strong technical support for the stable operation of the power grid. It also facilitates the international exchange and cooperation of China’s transformer products by aligning with international standards, enhancing the competitiveness of domestic transformer enterprises in the global market.
GB 1094.1-2013 is a comprehensive and forward-looking national standard that integrates international advanced experience with China’s industrial reality. Its detailed provisions on the general requirements of power transformers cover the entire lifecycle from design and manufacturing to transportation and operation. By complying with this standard, the power transformer industry can achieve standardized development, improve product quality, and better meet the needs of the national power system construction. With the continuous development of the power industry (such as the popularization of renewable energy power generation), the standard will continue to play a key role in guiding technological innovation and ensuring grid security.
References
- GB 1094.1-2013, Power transformers—Part 1: General[S]. Beijing: Standards Press of China, 2013.
- IEC 60076-1:2011, Power transformers—Part 1: General[S]. Geneva: International Electrotechnical Commission, 2011.
- National Standardization Administration of China. GB/T 1094.1-2013 Standard Information[EB/OL]. https://openstd.samr.gov.cn/bzgk/gb/newGbInfo?hcno=C3539A02733314553221D30BB7A2A0DF, 2013.