From May 5 to 9, 2025, the International Electrotechnical Commission (IEC) TC37/MT4 Working Group, the Institute of Electrical and Electronics Engineers (IEEE) Power & Energy Society (PES) held their joint spring working meeting in Clearwater, Florida, USA.
The meeting brought together over twenty technical experts from more than ten countries, including the United States, Germany, China, and Switzerland, for in-depth discussions on core standards for overvoltage protection and insulation coordination in power systems. Xi'an Tian Gong Electric CO.,LTD as a member of the IEC TC37 Chinese Working Group, participated in this joint meeting.
During the session, arrester technology experts from around the world focused on reviewing the draft of IEC 60099-11: Guidelines for Metal Oxide Surge Arresters (LSA) for AC Systems >1kV Lines, presented interim research findings on climate aging and radial stress testing, and held extensive discussions on revising application guidelines for grounding systems and surge arrester applications.
Chinese Proposals Gain International Recognition, with Core Technical Recommendations Incorporated into Standards
At this meeting, the Chinese Working Group collaborated closely to propose three key recommendations for the draft IEC 60099-11 standard:
1、Optimization of Dielectric Ratio Definition: Clarifying that the number of arrester resistor discs should be no fewer than three to enhance insulation reliability.
2、Supplement to Installation Classification: Refining technical specifications for arrester installation based on China's experience in UHV projects.
3、Addition of 30kA LSA Rating: Proposing the inclusion of a 30kA rating for LSAs (including EGLA and NGLA) used in China's UHV transmission lines to meet higher overvoltage protection demands.
Notably, the Chinese Working Group also called for revisions to address new transient overvoltage (TOV) conditions in renewable energy transmission projects. These proposals were highly praised by the IEC Working Group, which invited the submission of detailed engineering cases to accelerate standard implementation. This recognition not only underscores the high level of China's lightning arrester technology but also acknowledges the collective efforts of the entire Chinese lightning protection industry.
Additionally, at the IEEE PES session, discussions focused on revising standards such as IEEE Std C62.22-2009 Application Guide for Metal Oxide Surge Arresters for AC Systems and IEEE C62.92.1 ~ 6 Guide for the Application of Neutral Grounding in Electrical Power Systems. The Chinese Working Group actively participated in these discussions, sharing innovative achievements in grounding systems and arrester applications, thereby contributing valuable insights to the refinement of international standards.
Behind the technical proposals of the Chinese Working Group lies the collaborative innovation of the entire lightning arrester industry chain—from industry standard managers and testing centers to arrester manufacturers and key material suppliers for varistors, power hardware, silicone rubber, and zinc oxide. Every breakthrough reflects the ingenuity of China's lightning protection sector. The active participation of the Chinese Working Group in international standards meetings highlights the transition of China's power industry from "equipment manufacturing" to "standard leadership." As Chinese lightning protection technologies, such as UHV arresters and renewable energy protection, become reference points for international standards, we witness not only corporate achievements but also the collective outcome of years of technical research and collaborative innovation across the industry.
Looking ahead, TGE remains committed to the philosophy of "technology leadership and open collaboration." By working closely with all stakeholders in the industry chain, we will continue to contribute Chinese expertise to global power safety and sustainable development with cutting-edge technologies, improved standards, and reliable products.
"Showcasing the Innovative Power of China's Lightning Protection to the World."
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