Hangzhou, Zhejiang: Live-line overhaul in sweltering heat ensures reliable "cool power" for summer

The State Grid Hangzhou Power Supply Company's live-line specialists recently achieved a remarkable feat by completing  a challenging four-hour operation to upgrade the 1+1 pole on the Wanquan branch of the 10 kV Shangshan D540 line—all completed without interrupting power to customers. This upgrade has significantly enhanced the flexibility of the local distribution network and reduced the time required to isolate faults, marking another milestone in the company's ongoing efforts to strengthen the grid and ensure reliable electricity during peak summer demand. 

In today's era of increasingly intelligent and complex distribution networks, operators require swift and adaptable methods to reconfigure circuits and address faults promptly. The conventional tangent poles necessitate crews to deactivate upstream switches, impacting wide areas and consuming valuable time.

To address this—and to maintain uninterrupted power for customers—the company executed a complex live-line conversion. This involved transforming a tangent pole into a tension (angle) pole and installing a pole-mounted smart switch. Rated as a Category 4 project, the highest difficulty level in live-line work, the task required two weeks of meticulous site surveys and a carefully engineered procedure. During the operation, crews worked in relays, seamlessly transferring the full load to the newly installed smart switch and completing the conversion without any customer outages.

With this upgrade, the reliance on the main upstream breaker for switching or fault isolation branch is eliminated. The introduction of a new smart switch enables a simple local operation, effectively reducing the impacted area, minimizing restoration times, and boosting both reliability and customer satisfaction. Moreover, the new switch sets the stage for precise fault localization, automated isolation, and dynamic network reconfiguration.

Looking ahead, State Grid Hangzhou Power Supply Company is committed to further intelligent distribution network upgrades, expand the use of live-line techniques, and elevate standards for efficient operations and service quality. The ultimate goal is a stronger, smarter, and more flexible modern grid that supports economic growth and everyday life with unwavering reliability.