Sichuan's 500 kV Hongban line has been renovated, and the Sichuan-Chongqing power grid's transmission capacity has been enhanced.

China News Service, Chengdu, October 1 (Liu Zhongjun, Wang Zhiqi, Zeng Junjie) On October 1, Sichuan's 500 kV flood plate line completed comprehensive transformation and maintenance, the line was restored to operation, and the project was officially completed.

The Sichuan section of the 500 kV Hongban first-line transmission line. Photo by Wang Zhiqi

The Hongban Line starts from Zigong Honggou 500 kV substation and ends at Chongqing Banqiao 500 kV substation, with a total length of 148.77 kilometers, including 55.82 kilometers in the Sichuan section. It is one of the eight tie lines for clean energy transmission between Sichuan Power Grid and Chongqing Power Grid. The line was put into operation in March 1995 and has been in operation for more than 30 years. Some towers have corroded and aged and no longer meet the latest operating technical standards, affecting safe operation.

This comprehensive transformation is one of the key tasks of the autumn inspection of State Grid Sichuan Ultra High Voltage Company in 2026. Starting from September 15, the line entered the power outage phase. The construction line is more than 40 kilometers long. The main tasks include the construction of 23 new tower bases, the installation of 96 strings of tensile insulators and 63 strings of suspension insulators, 8 tightening wires and sag adjustments, and the "single to double" ground conductor hanging points at 6 base towers. It also involves "three-span" (across high-speed railways, highways and important transmission channels) tower construction and other difficult projects.

The most troublesome part in the renovation is how to arrange the power outage time. The project involves multiple power supply lines such as the 110-kilovolt Wuwang Line and the Wuxu Line. The window period is only three days, which is directly related to the holiday power consumption of tens of thousands of households. To this end, State Grid Sichuan Ultra High Voltage Company sent personnel to the site for inspection months in advance, proactively communicated and coordinated with relevant departments in Neijiang and Zigong, and dispatched additional on-site supervision and construction personnel to key links, key areas and special operating points. In the end, the work that originally took three days was compressed to two days. The relevant lines were restored to power before the holiday, and the public's electricity consumption and construction safety were not delayed.

It is reported that after the transformation is completed, the Sichuan-Chongqing power transmission channel will be safer and more reliable, and the power exchange capacity between the two places will be simultaneously enhanced.