Longde, Ningxia: High-Tech Powers Grid Stability During Peak Season

During the peak of summer, the Liupan Mountains are lush with greenery.On July 26, staff from State Grid Longde County Power Supply Company in Ningxia conducted a live-line installation of an Overhead Distribution Fault Early Warning and Location Device on the 10kV No. 521 Shanhe Line connected to the 35kV Taoshan Substation. The device can locate faults within 30 seconds, cutting troubleshooting time by 70%—a smart upgrade boosting grid reliability and precision in a region known for frequent thunderstorms and dense vegetation.

Overhead Distribution Fault Early Warning and Location Device

Photo by Xie Guoping

To address the operational challenges of 10kV lines such as the Chong’an and Shanhe lines, which traverse forested areas of the Liupan Mountains and face high stress during summer storms, the company has deployed 11 of these devices as a pilot. Each unit integrates three core functions: hazard prediction, fault localization, and status monitoring.

Hazard prediction: By detecting faint discharge signals from issues like loose fittings or degraded insulators, the device uses its traveling-wave fingerprint database to issue early warnings.Rapid fault identification: Triggered by sudden zero-sequence voltage changes, it initiates waveform recording and uses encrypted 4G transmission to locate faults within 30 seconds.All-weather operation: Powered by a hybrid system combining current transformer (CT) energy harvesting, solar power, and onboard energy storage, the device operates continuously in extreme temperatures from –40°C to 85°C.

Power workers install an Overhead Distribution Fault Early Warning and Location Device

Photo by Xie Guoping

Compared with traditional impedance-based fault location methods, this system is unaffected by line parameters and is ideal for complex distribution networks. It can detect high-resistance ground faults up to 5 kΩ, with sensitivity 20 times higher than conventional approaches.

Since this summer, the 11 pilot units—dubbed “power sentinels”—have been operating continuously, providing real-time monitoring and strengthening the safety and stability of the grid across the Liupan Mountain region.(By Xian Guoping, Ma Jun, Yang Yunying)