In the forefront of power transmission technology, the innovative research, development, and application of the 750-kilovolt (kV) ultra-high voltage (UHV) cable system have garnered considerable attention.
Background and Overview
Recently, China Three Gorges Construction Group, in collaboration with enterprises such as Qingdao Han Cable Co., Changzhou Cable Technology, and the China Electric Power Research Institute, successfully developed a 750 kV UHV cable system. This system has passed national product certification, further validating its performance and reliability. This breakthrough not only represents a significant achievement for China in high-voltage power transmission but also establishes China’s position as a technological leader in the global UHV cable industry. The system’s adoption of both flat and corrugated aluminum sheath technologies holds global significance, setting a benchmark for efficient power transmission and grid upgrades for other nations.
Technological Breakthroughs: Core Innovations and Achievements of the 750 kV UHV Cable System
The success of this 750 kV UHV cable system results from multiple technological breakthroughs. The R&D team overcame critical technical challenges associated with flat and corrugated aluminum sheaths, ensuring insulation and stability at ultra-high voltages. They also developed liquid-filled insulated composite casing terminations and dry-type insulated GIS terminations, providing superior safety and stability for the system.
Remarkably, the system passed rigorous testing at the China Electric Power Industry Electrical Equipment Quality Inspection and Testing Center, becoming the first 750 kV UHV cable system to complete comprehensive testing of both flat and corrugated aluminum sheaths. This achievement not only advances UHV cable technology but also provides new insights for power transmission in other sectors.
Technical Innovations of the 750 kV UHV Cable System
During the development of the 750 kV UHV cable system, the team achieved innovation across several technical fields. This project aims to offer a more efficient solution for large-scale, long-distance power transmission to ensure the stability and safety of high-voltage transmission. Key technological innovations include:
Breakthroughs in Flat and Corrugated Aluminum Sheath Technologies
The 750 kV system incorporates both flat and corrugated aluminum sheaths, improving the cable’s durability and stability to meet diverse environmental needs. The flat aluminum sheath is structurally robust and lightweight, suitable for long-distance power transmission in specific environments. Meanwhile, the corrugated aluminum sheath’s flexibility suits scenarios where cables require extensive bending. These innovations enhance the cable’s mechanical properties and increase its durability in challenging environments.
Development of Liquid-Filled Insulated Composite Casing Termination
The development of the liquid-filled insulated composite casing termination marks a critical innovation within the 750 kV UHV cable system. Designed to provide insulation and sealing in the cable system, this termination uses liquid-filled materials to deliver excellent insulation, reducing heat loss due to high voltage and further stabilizing cable operation.
Innovative Design of Dry-Type Insulated GIS Termination
The dry-type insulated gas-insulated switchgear (GIS) termination’s innovative design expands the application scope of the cable system. Using high-seal materials and unique design elements, this termination enhances the system’s insulation capabilities, improving overall cable safety and providing a reliable choice for 750 kV voltage-level power transmission.
Successful Completion of Comprehensive Type Testing
Every core technology and component within the 750 kV cable system has undergone extensive type testing, evaluating its heat resistance, tensile strength, and stability in high-voltage environments. The success of these tests demonstrates the system’s effectiveness across diverse transmission environments and validates its overall reliability.
Market Demand and Global Application of the 750 kV UHV Cable
Background for UHV Cable Application
The 750 kV UHV cable is primarily used in high-voltage long-distance transmission systems, significantly reducing energy losses over long distances and lowering energy costs. In recent years, regions around the world have increased investments in UHV transmission technology to enhance grid efficiency, reduce power losses, and optimize energy use.
Rapid Growth of UHV Cable Market Demand
With the increasing global demand for clean energy and long-distance power transmission, the UHV cable market is expanding rapidly. The 750 kV cable system is especially in demand for long-distance, interprovincial, or international transmission projects. For example, transnational projects such as grid interconnections between Central Asia and South Asia require high-performance UHV cable technology to ensure efficient power transmission.
Flexibility in Adapting to Climate and Environmental Challenges
The development of both flat and corrugated aluminum sheath technologies enhances the environmental adaptability of the 750 kV system. The options of sheath types account for variations in temperature, humidity, pressure, and corrosive factors, allowing the system to perform stably in extreme conditions and ensuring its resilience in challenging environments.
Application Scenarios and Technical Advantages of the 750 kV UHV Cable
The 750 kV UHV cable system offers significant technical advantages across various application scenarios:
A Core Choice for Critical Transmission Lines
The 750 kV cable system is commonly employed in UHV transmission lines and interprovincial or international power grid projects. The system’s high transmission efficiency and low energy consumption characteristics provide solid support for the grid, reducing power losses and enhancing grid stability.
Stable Material Performance and Strong Environmental Adaptability
The flat and corrugated aluminum sheath technologies enhance both the cable’s mechanical strength and its resistance to corrosion and high temperatures, enabling stable operation even under extreme conditions. This design ensures the cable’s long lifespan and durability.
Support for Green and Clean Energy Transmission
With the global shift toward clean energy, UHV cables enable efficient transmission of renewable energy, particularly for connecting distributed generation plants, such as wind and solar farms, to the grid, minimizing environmental impacts from traditional energy sources.
Future Prospects of 750 kV UHV Cable Technology
The advancements in the 750 kV UHV cable system have a significant impact on the development of global power transmission technology. With continued research into cables at the 750 kV level and above, more countries and companies are increasingly investing in grid upgrades and energy efficiency improvements.
Technological Breakthroughs Driving Industry Progress
The innovative development of the 750 kV UHV cable system has set higher standards for cable manufacturing processes, fostering the adoption of advanced materials and equipment, and contributing positively to industry progress.
Extensive Global Market Potential
In the future global power market, 750 kV and higher voltage-level cables will see widespread application in high-voltage transmission projects. This technology not only reduces power transmission losses but also modernizes global power infrastructure, ensuring efficient transmission of clean energy.
VII. Conclusion
The innovative development of the 750 kV UHV cable system is of great importance for advancing power transmission technology. The breakthroughs in flat and corrugated aluminum sheath technologies, liquid-filled insulated composite casing terminations, and dry-type insulated GIS terminations bring fresh momentum to the 750 kV cable system. As global power demand and grid interconnections increase, this system will continue to expand its application fields, facilitating the efficient and stable transmission of energy worldwide.
