Power Grid Upgrade Campaign Concluded! Full Efforts to Safeguard “China’s No.1 Hickory Town”

On September 24th, as the final newly installed circuit breaker cabinet at the 35kV Daoshi Substation passed its live operation test, with its operational indicator lights glowing steadily, the three-day intensive effort by the project team culminated in success. The 35kV Power Distribution Equipment and Bay-Level Device Upgrade Project at the 35kV Daoshi Substation was officially declared operational. Having served “China’s No.1 Hickory Town” for nearly two decades, the substation has undergone “a fundamental transformation”. With its new “core systems” now online, it embarks on a new chapter of power supply reliability, solidifying the electrical safety net for the local deep processing season of hickory nuts and the upcoming autumn and winter production and daily life demands.

“Every day we can bring this project online earlier means an extra layer of reliability for the public’s power supply!” said project manager Chen Jia, his tone filled with urgency as he surveyed the new indoor equipment bay. The pressing need for this upgrade stemmed from the increasingly prominent issue of equipment aging at Daoshi Substation: the outdoor AIS (Air-Insulated Switchgear) equipment, operational for nearly 20 years, utilized a line-transformer unit connection scheme without a circuit breaker, relying solely on high-voltage fuses for protection. In the event of a fault, manual on-site intervention was required, leading to inefficient power restoration. The outdoor disconnecting switches, exposed to the elements for years, suffered from severe mechanism jamming and corrosion. The bay-level protection and measurement/control devices, commissioned in 2008, were plagued by frequent malfunctions and aged components. Their maintenance costs rose year by year, and they had long fallen short of meeting current demands for refined grid operations and the reliable power supply.

More critically, as “China’s No. 1 Hickory Town”, Daoshi Town enters September—the peak period for deep processing following the hickory nut harvest. Every household sees drying rooms and processing factories operating at full capacity, making the power supply “absolutely indispensable”. To balance project progress with residential electricity demand, State Grid Hangzhou Power Supply Company commenced the commissioning work immediately during the first week after the peak summer load period, leveraging the concurrent drop in both temperature and electricity demand. This approach not only avoided peak usage times but also ensured the upgrade was completed before the critical processing window for the hickory industry. Each step of the project’s advancement was closely tied to regional industrial development and public well-being.

As a key annual project for the Lin’an power grid, the company attached high priority to its advancement, establishing a dedicated task force composed of key personnel from the Operations and Maintenance Department, the Transmission and Distribution Operations and Inspection Center, and the Dayou Lin’an Branch Power Engineering Company. This team closely monitored progress throughout the entire project lifecycle, from initial planning to on-site construction. A rigorous management mechanism was implemented, featuring “morning briefings for task assignment, afternoon reviews of progress, and evening meetings to resolve issues”. Detailed schedules with strict milestones were created for critical stages such as equipment transportation, indoor wiring, and debugging/commissioning, ensuring all daily targets were met without delay. On-site, eight new circuit breaker cabinets stood neatly aligned in the indoor equipment room, a stark contrast to the old, exposed outdoor equipment they replaced. “Relocating all equipment from an ‘outdoor’ to an ‘indoor’ environment not only effectively protects it from weather erosion but also minimizes operational interference from environmental factors, making future maintenance safer and more efficient, ” explained Chen Jia. The upgrade involved the installation of eight new circuit breaker cabinets, one station transformer, the replacement of six 10kV current transformers, and 27 sets of protection and control devices. The comprehensively upgraded system now features real-time status monitoring and automatic fault warning capabilities, leading to a substantial increase in power supply reliability.

Simultaneously, the project served as a “practical training ground” for the growth of young employees. Five early-career substation specialists were integrated into the dedicated team, forming “1+1” mentoring pairs with experienced senior engineers. They participated fully in core tasks such as equipment installation, parameter setting, and fault simulation exercises. “Debugging protection devices on-site alongside my mentor allowed me to truly understand the equipment principles and, more importantly, learn how to respond to unexpected issues. This is invaluable experience you cannot get from textbooks,” shared Pang Songtao, one of the young engineers, noting that the hands-on experience has significantly boosted his confidence.

The upgraded Daoshi Substation now marks a leap from “aging outdoor maintenance” to “intelligent indoor control”. Looking ahead, State Grid Hangzhou Power Supply Company will continue to ensure robust post-upgrade operation, maintenance, and monitoring of the new equipment. This commitment to high-quality power supply will safeguard the industrial development of “China’s No. 1 Hickory Town” and inject stronger momentum into both the power grid modernization of Hangzhou’s western mountainous areas and the region’s high-quality economic development.   (Text by Fu Yunxiao, Photo by Wu Chen)