Guyue substation's overhaul put into use

State Grid Shaoxing Power Supply Co (State Grid Shaoxing) completed the comprehensive overhaul of the 220-kilovolt (kV) Main Busbar Section I at the 500-kV Guyue Substation on April 28. The 16-day overhaul, carried out by the company, is expected to boost local industrial development.

The Guyue substation. [Photo provided to chinadaily.com.cn]

Located in Binhai Industrial Park in Keqiao district, Shaoxing, the 500 kV Guyue Substation is the only 500-kV substation in the park. Since its commissioning in July 2007, it has served as the primary power supply for northern Keqiao in Shaoxing and eastern Xiaoshan in Hangzhou. In recent years, as Keqiao’s textile printing and dyeing industry has become increasingly centered in the Binhai Industrial Zone, regional power loads have continued to rise, straining grid equipment. The 220 kV Main Busbar Section I at Guyue Substation had reached its six-year scheduled maintenance period, with a thorough check-up performed to eliminate equipment hazards and improve regional power supply reliability. 

This comprehensive overhaul covered the 220 kV Main Busbar Section I and 11 associated 220 kV bays, including the Gutai 4Q81 and Guyi 4Q88 lines, involving 67 units/sets of core primary and secondary equipment, such as busbars, circuit breakers, disconnectors, and protection devices. To avoid errors, the company assembled a specialized task force by coordinating key personnel from multiple disciplines—ultra-high-voltage operation and maintenance, primary and secondary equipment maintenance, and high-voltage testing. Given the complex structure of the air-insulated switchgear (AIS) and stringent maintenance standards, standardized operating procedures were developed in advance.

A worker maintains the lines. [Photo provided to chinadaily.com.cn]

During the overhaul, the team set a goal of zero defects and performed every step with the utmost caution. From equipment cleaning, disassembly, and installation to testing, measurement, and protection calibration, staff members managed safety boundaries and quality standards throughout the process. Forced to manage overlapping worksites as well as external construction personnel, the team optimized work sequences and refined responsibilities for management. They overhauled equipment, eliminated defects, implemented safety measures, and performed lean evaluation rectifications. In total, 16 items of C-level maintenance were completed, four sets of line arresters replaced, eight hidden hazards and defects eliminated, and two lean evaluation issues addressed.

The successful completion of the Guyue Substation comprehensive overhaul has strengthened the reliability of the park's core power supply hub, delivering solid power support for the local textile printing and dyeing industry. Moving forward, State Grid Shaoxing will continue to focus on industrial electricity demand, strengthen lean equipment operation and maintenance, and steadily advance power grid construction projects, providing a strong power guarantee for the safe operation of the main grid and high-quality industrial development during the 15th Five-Year Plan period (2026-30).