On August 19, the State Grid Operation and Maintenance Department announced that the State Grid Corporation of China has established a working group composed of the Operation and Maintenance Department, Infrastructure Department, Safety Supervision Department, National Dispatch Center, and China Electric Power Research Institute to accelerate the promotion and application of parallel gap technology for overhead transmission lines.
It is understood that the working group's work will focus on the following aspects: optimizing the technical parameters of parallel gaps, standardizing the specifications and models of parallel gaps, improving the technical guidelines for parallel gaps, and clarifying the selection principles, application scope, and installation and acceptance standards for parallel gaps; proposing reasonable lightning tripping rate indicators for lines with installed parallel gaps, and reasonably adjusting the requirements for lightning fault inspection of lines with installed parallel gaps to effectively reduce the workload of line fault inspection; increasing the number of pilot application units and lines for parallel gaps, and gradually extending the pilot scope to all 500 kV and below voltage level transmission lines of provincial companies; gradually carrying out pilot applications on infrastructure engineering lines based on a careful summary of operational experience, striving to achieve the comprehensive promotion of parallel gap technology in the company's infrastructure and renovation projects; strengthening the refinement, summarization, and promotion of research and pilot application results of parallel gap technology for transmission lines, promoting the continuous and effective implementation of parallel gap installation work, and ensuring practical results.
Parallel gap lightning protection technology utilizes gap devices connected in parallel to both sides of an insulator string to intercept lightning strikes, divert power frequency arcs, and prevent insulators from being burned by arcs. This helps improve line resynthesis power and reduce operation and maintenance workload, and is widely used in Europe, Japan, and other countries and regions. In recent years, with the continuous strengthening of the power grid structure and the large-scale use of sulfur hexafluoride switchgear and microprocessor-based protection devices, the conditions for the company to promote and apply parallel gap technology have been met. Since 2010, the State Grid Operation and Maintenance Department has organized the China Electric Power Research Institute to conduct research on the application of parallel gap technology for insulators on 110 kV to 500 kV lines. Pilot applications of parallel gap technology have been carried out on 118 lines totaling 2540 kilometers of 35 kV to 500 kV lines in State Grid Beijing, Hebei North, and Zhejiang Electric Power units, effectively reducing the lightning strike failure rate, protecting insulators, and reducing the workload of fault inspection.
