Spring inspection wraps up at 500kV Zhuji Substation

An employee conducts a spring inspection in Shaoxing, Zhejiang province. [Photo provided to chinadaily.com.cn]

The power transmission of the No 4 main transformer at the 500kV Zhuji Substation has been completed, concluding the largest and longest ultra-high voltage spring maintenance project in the Shaoxing grid for 2026. The work has strengthened power supply reliability for the looming peak in summer.

The 500kV Zhuji Substation, the sixth of its kind in the Shaoxing area, plays a key role in receiving clean electricity from the Lingzhou-Shaoxing ultra-high voltage direct current transmission project. A supporting 500kV project connecting the Gansu-Zhejiang ultra-high voltage direct current transmission line to the substation is progressing efficiently and on schedule.

In the future, this will allow interconnection with the 500kV AC system at the Yuezhou Converter Station, helping integrate clean energy from Gansu into the Shaoxing grid.

Staff members conduct a spring inspection in Shaoxing, Zhejiang province. [Photo provided to chinadaily.com.cn]

Alongside grid expansion, equipment reliability has been reinforced. This maintenance work used the outage window created by the 500kV supporting project for the Gansu-Zhejiang ultra-high voltage direct current transmission line.

More than 1,000 workers took part, replacing three 500kV circuit breakers and seven disconnector mechanisms, and overhauling 198 units of equipment — including three main transformers and three 500kV transmission lines.

To address space constraints in composite apparatus, the team applied a hydraulic lifting method instead of conventional lifting, improving both maintenance quality and site safety. The successful overhaul has further secured the 500kV grid in Shaoxing, providing ample green power for local industrial upgrades and keeping residents cool in summer.

A view of the inspection site in Shaoxing, Zhejiang province. [Photo provided to chinadaily.com.cn]

As temperatures rise, State Grid Shaoxing Power Supply Company will concentrate its best resources, seize the final window for summer peak preparations, conduct comprehensive health checks and targeted repairs, and strengthen quality control on new equipment — ensuring the grid is fully ready for the critical task of ensuring a safe and stable summer power supply.