The Hanzhong 750 kV power transmission and transformation project, led by China Energy Engineering Shaanxi Institute and designed with the participation of Northeast Institute, has been officially put into operation. This energy artery that runs through the Qinling Mountains is not only the first 750 kV transmission line in China to cross the Qinling Mountains, but also sets multiple industry records, marking the official upgrade of the power grid in southern Shaanxi to the 750 kV voltage level, injecting strong power into regional energy supply and clean energy consumption.

Multiple technological breakthroughs

As a key project for upgrading the backbone network of Shaanxi power grid, the Hanzhong 750 kV transmission and transformation project faces the complex challenges of "large height difference, large span, and repeated icing" in the Qinling Mountains, achieving multiple technological innovations. The total length of the project line is 459 kilometers, starting from Baoji Converter Station in Fengxiang District, Baoji City, and ending at the newly built Hanzhong 750 kV Substation in Chenggu County, Hanzhong City. The maximum designed ice cover thickness in some areas along the route is 40 millimeters, which is unprecedented in 750 kV voltage level projects.

To solve this technical problem, the design team conducted 14 specialized studies and pioneered a complete design scheme for a 40mm heavy ice area with a voltage level of 750 kV, filling the domestic technological gap; For the first time, the differentiated design of ultra-high voltage "two big and two micro" has been introduced in the 750 kV transmission line in Shaanxi, and more than 140 iron towers have been customized according to the "tailor-made" design, with the highest tower reaching 111 meters and weighing 330 tons. At the same time, four automatic icing and micro meteorological observation stations are set up along the line to provide scientific monitoring support for the safe operation of the power grid under extreme weather conditions.

Creating benchmark samples for power grid engineering

The design concept of "green, low-carbon, intelligent and efficient" runs through the entire process of engineering construction, achieving a dual breakthrough in ecological protection and technological empowerment. In terms of ecological and environmental protection, the design team intelligently selected routes through four sets of path schemes to avoid nature reserves to the greatest extent possible; Adopting measures such as cableway transportation, topsoil restoration, and shrub planting to achieve a 100% ecological restoration rate along the project route; The substation building incorporates Han Dynasty eaves elements, perfectly integrating engineering aesthetics with regional culture.

In terms of intelligent construction, the whole station is equipped with a one click sequential control function, and a dual-mode control architecture is built between the centralized control station and the station end. The three-stage closed-loop error prevention system of "pre operation rehearsal, operation monitoring, and post operation review" is innovated, and the switching operation time is shortened by more than 60%, the risk of misoperation is reduced by 90%, and "unmanned and remote control" is achieved. In addition, the pioneering 750 kV GIS equipment "vertically adjustable expansion joint+independent foundation" solution not only solves the problem of gas leakage in long-distance pipelines, but also saves concrete usage; The main transformer adopts high-efficiency energy-saving equipment and the whole station LED lighting linkage control, which can reduce energy consumption by more than 550000 kilowatt hours per year.

After being put into operation, the project will increase the power supply capacity of Hanzhong Power Grid by 25%, reduce carbon dioxide emissions by about 15 million tons annually, significantly enhance the reliability of the regional power grid, open up a key channel for efficient grid connection and external transmission of clean energy in southern Shaanxi, and help promote the green and low-carbon development of local economy and society.Editor/Bian Wenjun