Qujiang project one step closer to completion

On Aug 10, State Grid Xi'an Power Supply announced that the civil construction phase of the Qujiang 330-kilovolt transmission and transformation project was complete. The project, a key power initiative in Shaanxi province and part of Xi'an's Three-Year Electric Safety Capacity Enhancement Action Plan, has now moved into the electrical equipment installation phase.

The Qujiang project involves installing four 360-megavolt-ampere main transformers, four 330-kV incoming lines, and 22 outgoing 110-kV lines in the future. All standard construction and safety inspections have been completed, confirming that the civil engineering work meets requirements for the next phase, ensuring a smooth transition to the electrical installations.

"The project underwent four rounds of site selection and over 10 revisions to its line plan, carefully balancing urban development, cultural heritage, and ecological conservation. It was a collaborative effort involving government, enterprises, and local residents," said Zhang Yibin, project manager at State Grid Xi'an Power Supply. The project includes a 330-kV indoor substation, outdoor cable terminal site, overhead lines, and cable lines, making it the most comprehensive and technically complex 330-kV project in China in terms of voltage elements.

The construction team tackled numerous technical hurdles, such as crossing metro lines, executing ultralong pipe jacking, and the reverse construction of deep foundation pits. It set a new standard for the complexity of ultrahigh-voltage cable tunnels in Shaanxi's power grid. This project also marks the first large-scale use of domestically produced insulation materials in a complete 330-kV cable system, paving the way for the localization of core materials for ultrahigh-voltage cables.

The accompanying cable project posed its own challenges. "This is State Grid Xi'an Power Supply's first independently constructed and managed cable project and its largest to date," said Tian Heng, deputy director of the construction department of the company.

Faced with a complex construction environment and a lack of prior management experience, the company developed an innovative "123 working method". This aims to create a model case of ultrahigh-voltage cable transmission engineering, combining expertise from traditional electrical teams and municipal engineering specialists, and establishing three management systems for unified oversight, interdepartmental cooperation, and engineering control.

This approach coordinated key phases, including route selection, administrative approvals, groundbreaking, specialized construction, and multiparty coordination. To date, 13 of the 15 tunnel sections and 14 of the 15 working shafts have been completed.

The project also emphasizes green construction, incorporating low-carbon and environmentally friendly practices. Measures such as static pile pressing and dust- and noise-control canopies have minimized the effects on surrounding residents and the urban environment, setting a "Qujiang Standard" for high-voltage urban grid projects. This provides a replicable model for building dense and complex urban power grid infrastructure.

The Qujiang 330-kV project is set to begin operations in June 2027. Once operational, it will provide a strong energy foundation for the development of the Qujiang Science and Technology Innovation Park, the High-Speed Rail East City area, and other urban and industrial projects, while also supporting residential energy needs. This project is expected to inject new momentum into the energy network in southeastern Xi'an.