Converter station upgrades control systems

The 2026 annual maintenance and control protection retrofitting starts at Baoji Converter Station. [Video provided to chinadaily.com.cn]

More than 700 workers have been carrying out annual maintenance and a major control system upgrade at the Baoji converter station in Shaanxi province since prior to the National Day holiday. This will help to ensure reliable power transmission between Northwest and Southwest China ahead of the winter peak demand season.

The overhaul, launched on Sept 20 and scheduled for completion on Nov 18, involves 9,838 maintenance tasks. It will mark the first domestic replacement in the State Grid system of valve control equipment using Siemens technology with a dual-redundancy configuration.

The upgrade will modernize the station's core control and protection systems, improving the reliability of the Debao direct-current transmission link and strengthening cross-regional power delivery.

As the starting point of the ±500-kilovolt Debao project, the station transmits thermal and wind power from Northwest China to Sichuan province during dry seasons, and clean energy from Sichuan to Shaanxi during periods of abundant hydropower, facilitating complementary power supplies between the two regions.

The project involves removing 77 control panels, installing 94 new ones and upgrading 222 others, as well as rewiring tens of thousands of secondary cables. To address compatibility challenges between old and new systems, engineers have built a simulation platform to test control logic, communications protocols and system coordination.

The overhaul also includes optimized maintenance procedures and improvements to valve cooling system controls, helping enhance operational safety and efficiency.