As an important hub substation for transferring electricity from north to south and east to west in the East China region, the Zhenjiang 500-kilovolt Shangdang Substation No 2 main transformer capacity expansion and renovation project was put into operation on June 1, upgrading the regional power grid equipment level and ensuring reliable power supply during the peak summer period.

As the first 500-kV substation in Zhenjiang, the Shangdang Substation was put into operation in January 2007, connecting Nanjing and Changzhou. It undertakes the task of transmitting power from the Jianbi Power Plant's two 600,000-kilowatt units and serves as an important power supply channel for the southern Jiangsu power grid.

The station has a total of four main transformers. The No 1 and No 2 main transformers with the capability of 750 mega volt-ampere have been in service for more than 20 years. At the end of last year, the State Grid Zhenjiang Power Supply Company completed the replacement of the No 1 main transformer. This time, the replacement of the No 2 main transformer will increase the supply capacity by approximately 500,000 kilovolt-ampere, to better meet the region's growing electricity demand. Additionally, this replacement project utilized dust-free installation processes, and installed monitoring facilities such as million-level particle size monitors, air purifiers, and temperature and humidity meters. The efforts greatly optimized the construction process and ensured efficiency of the main transformer replacement project.

After the completion of this capacity expansion and renovation, all four 500-kV substations in the Zhenjiang area will have achieved full localization of their main transformers, which can enhance equipment reliability and maintenance convenience, reduce procurement and maintenance costs by over 40 percent, and drive the high-quality development of the power equipment industry upstream and downstream in the Jiangsu province.