Hangzhou Pilots Practical Implementation of Overhead Line Grounding Section Selection Function

At 6:04 PM on August 21, the distribution automation master station system of State Grid Hangzhou Power Supply Company suddenly received an alarm signal from the Gaoling V293 line in Lin’an District. Remarkably, the system accurately pinpointed the fault section within just 51 seconds, automatically generated a response plan, and completed Hangzhou’s first intelligent diagnosis and isolation of a distribution line grounding fault.

This marks the official entry of the company’s distribution operation and maintenance into an intelligent era characterized by “second-level positioning and minute-level response”. It also signifies that Lin’an has become the first county-level district in the province to implement the overhead line grounding section selection function.

As a typical mountainous county, Lin’an has complex terrain and extensive overhead lines, with a total line length exceeding 3,528 kilometers. In the past, when a grounding fault occurred, operation and maintenance personnel had to traverse mountains and forests, checking the lines section by section, often taking several hours or even longer.

This breakthrough technology is attributed to the newly deployed pole-mounted intelligent switch system by State Grid Hangzhou Power Supply Company. Like installing “smart eyes” and “sensitive noses” on the power grid, these intelligent switches can perceive line abnormalities in real-time and accurately capture fault signals. When a grounding fault occurs at a certain point on the line, the intelligent switch immediately collects current and voltage data, quickly identifies the anomaly through analysis, and sends an alarm to the master station system at the first opportunity.

“In the past, finding a line fault point was like looking for a needle in a haystack, requiring operation and maintenance personnel to check the lines section by section under scorching sun or cold wind, often taking several hours,” said Ma Jingyi, monitor of the Lin’an Automation Maintenance Team at State Grid Hangzhou Power Supply Company. “Now, the intelligent switch can accurately locate the fault section within a minute, and dispatchers can remotely isolate the fault and restore power.”

The successful pilot operation is credited to a self-developed intelligent diagnosis algorithm. The system acts like an experienced “power doctor”, quickly “diagnosing” the fault location based on data returned from the intelligent switches and providing the optimal “treatment plan”. Currently, this function has been activated on 878 intelligent switches across 373 lines in the Lin’an area, laying a solid foundation for full-scale promotion.

For ordinary residents, the significance of this technology lies in more reliable power supply. When a line fault occurs, the outage area will be confined to the smallest possible section, significantly reducing the number of affected users and shortening the time to restore power. Especially under adverse weather conditions, the intelligent system can respond quickly, minimizing the impact of outages on residents’ lives. (By Chen Zao/Fu Yunxiao)