Technical upgrades and annual maintenance propel Zhoushan's flexible DC project
On Nov 1, the State Grid Zhoushan Power Supply Company initiated a simultaneous launch of upgrades in flexible direct current (DC) technology alongside its annual maintenance efforts. This "dual drive" approach integrates technical transformation with precision inspection to significantly enhance the operational reliability of core flexible DC equipment.
The technical upgrade focuses on adapting the system to the new grid configuration following the integration of Shengsi offshore wind power. In collaboration with the Electric Power Research Institute and equipment manufacturers, the project team is tackling key technical challenges including secondary system upgrades for DC control and valve management, optimization of control logic, and improvement of interlocking protection functions. Through comprehensive joint testing at the factory, multiple control and protection function verifications have been completed, ensuring precise performance in critical scenarios such as sequence control and fault response. The upgraded flexible DC system will exhibit enhanced flexibility, stability, and autonomous controllability.
In parallel, the annual maintenance operation proceeded in full swing. The maintenance team conducted a comprehensive "full-system checkup" on core equipment such as converter station valve towers, valve cooling systems, transformers, and undertook cable trench remediation and optical CT cable installation, ensuring equipment reliability throughout the system.
To ensure efficient on-site coordination, Zhoushan Power Supply Company activated a "wartime" operation mode, with unified command, strict responsibility implementation, and meticulous control of safety and quality standards at every stage. Adhering to the operational philosophy of "individual precision, team collaboration," the company demonstrated its hallmark professionalism, discipline, and teamwork, creating a zero-risk, high-standard work site—fully showcasing the company’s resilient and highly capable engineering strength.
