HENGTONG Successfully Completes Type Test for 750kV Ultra-High Voltage Cable with Record-Breaking 2500mm² Large-Cross-Section Conductor, Boosting Transmission Capacity by 23%

Recently, HT, in collaboration with partners, has successfully completed the type test for a 750kV ultra-high voltage cable system, setting a new domestic record with its 2500mm² conductor—the largest cross-section for this voltage level in China. This breakthrough highlights HT's R&D capabilities in ultra-high voltage cable technology and lays a critical foundation for future high-capacity, high-reliability power transmission networks.

Breaking Production Barriers for Higher Transmission Capacity

The tested 750kV cable system adopts a 2500mm² ultra-large cross-section conductor. Compared to conventional 1600mm² cables at the same voltage level, its outer diameter increases by only 10%, yet it achieves up to 23% higher transmission capacity—significantly widening the power transmission "artery" for a substantial leap in efficiency.

Producing such an oversized cable posed major challenges, with only a 4mm clearance between the insulated core and production equipment. To overcome these hurdles, the project team conducted multiple technical reviews, analyzing and validating each process step to optimize both quality and efficiency. With guidance from equipment manufacturers' experts, HT successfully broke through production bottlenecks, delivering China’s first 2500mm² ultra-high voltage cable—a milestone in translating theoretical design into real-world application.

Innovation Through Industry-Academia-Research Collaboration

This achievement was made possible through a joint effort by HT, Shanghai Electric Cable Research Institute (SECRI), and Changyuan Technology Group, combining their expertise in high-voltage cable manufacturing, accessory R&D, and testing. Together, they tackled critical challenges such as uniform insulation extrusion for large cross-sections and electric field control in cable terminations, laying a solid technical foundation for future grid projects and advancing China’s ultra-high voltage cable technology toward self-sufficiency and global leadership.

Powering the New Energy Grid

750kV ultra-high voltage cables are core components for:
✔ UHV power grids & long-distance clean energy transmission
✔ Offshore wind farm grid integration
✔ Urban underground high-voltage networks

This breakthrough not only fills a domestic technical gap but also provides critical infrastructure support for clean energy expansion and grid modernization under China’s "Dual Carbon" (Carbon Peak & Neutrality) goals.

Moving forward, HT will continue driving industry chain upgrades, delivering smart, green energy solutions to accelerate the global transition to sustainable power systems.