Since the onset of the major flood season, frequent severe convective weather and heavy downpours have struck numerous areas across Gansu, with some regions suffering continuous torrential rains. This has drastically increased risks to power grid facilities including lightning strikes, water inundation and mountain landslides. Faced with severe pressure on flood control and power supply guarantee, the State Grid Qingyang and Pingliang Power Supply Companies adhere to the work guideline of preparing for severe floods, responding to major emergencies and securing power supply. All staff maintain round-the-clock on-duty shifts, and build a robust flood prevention network for power utilities through frontline emergency repairs and special equipment inspections, so as to fully guarantee stable grid operation and reliable electricity supply for local residents.

On July 27, technicians from State Grid Qingyang Power Supply Company conducted lightning arrester installation and renovation on the 35kV 3513 Zhenping Line. The construction work reduces the probability of line tripping failures caused by thunderstorms through source control, consolidating the safety foundation of residential power supply in summer.

From the night of July 25 to July 26, Qingyang City was hit by widespread sustained heavy rainfall. The cumulative rainfall in towns including Nanchuan and Qichuan of Zhenyuan County exceeded 150 millimeters, prompting an emergency upgrade of local rainstorm alert from orange to red, bringing huge challenges to flood control and power supply across the region. State Grid Qingyang Power Supply Company activated the flood emergency response without delay. All cadres and staff reported to posts rapidly, fully switching to emergency operation mode to tackle the extreme rainstorm disaster.

On July 27, the company’s technicians carried out special inspections on metering devices at distribution transformer stations in Jianggoumen Village, Nanchuan Township, Zhenyuan County, detecting and eliminating potential equipment defects in advance to reinforce the safety barrier of power operation during flood season.

Following the working mechanism of early deployment, early inspection and early remediation, Qingyang Power Supply Company seized sunny weather windows before the flood season to fully advance special lightning protection renovation for transmission lines. Lightning arresters were intensively installed on lightning-prone sections and key towers of 35kV main lines, aging and invalid lightning protection equipment was replaced one by one, and line grounding devices were systematically optimized to shore up weak lightning protection links of the grid. A complete lightning protection shield has been built for all transmission lines, fundamentally cutting down risks of equipment damage and line outages triggered by heavy rains and thunderbolts, thus securing the initiative in flood and lightning prevention work.

Amid the overlapping summer peak power demand and flood season power guarantee period, the company increased the frequency of special inspections for power lines and substation equipment, and consolidated the primary flood control management responsibility of all substations. During rainstorms, operation and maintenance staff braved wind and rain, waded through accumulated water to conduct on-site inspections at key transmission corridors, suburban branch lines and distribution facilities in low-lying areas. Professional testing tools such as infrared temperature measurement and ground resistance detection were adopted to verify the operating status of every tower, line and equipment, accurately mastering equipment insulation and grounding performance to ensure sound and stable operation of grid facilities under rainstorm conditions.

On July 27, operation and maintenance staff of State Grid Qingyang Power Supply Company went deep into farmlands and villages of Nanchuan Township, Zhenyuan County, inspecting rural transmission poles tower by tower and reinforcing pole foundations loosened by rain erosion. These measures effectively prevent pole tilting and collapse risks caused by soil erosion in flood season, safeguarding the bottom line of safe operation of rural power grids.

The company refined full-process flood and drainage control for all local substations: drainage pipelines inside stations were dredged in advance, flood control sandbags were neatly stacked at wall bases and high-voltage equipment zones, and water pumps, emergency lighting and other flood-fighting supplies underwent full maintenance and commissioning. Special waterproof and anti-seepage renovations were implemented for main control rooms and high-voltage equipment areas, with regular emergency response plans formulated for ponding risks to enable rapid disposal and efficient drainage. Meanwhile, operating parameters of substation lightning protection equipment are calibrated periodically. The company synchronizes lightning protection renovation with flood control management, equipment inspection with hidden danger rectification, and safeguards the red line of grid safety in flood season through full-coverage and uninterrupted troubleshooting.

On July 26, Pingliang City issued a red rainstorm alert. Continuous heavy rainfall raised river water levels, and soil on river valley slopes was eroded by rainwater, leading to mounting risks of geological disasters including landslides and collapses. State Grid Pingliang Power Supply Company activated the emergency response plan immediately, strictly implemented a 24-hour on-duty system, and kept all staff on standby to respond to extreme rainfall disasters.

On July 27, technicians from the Transmission Inspection Center of State Grid Pingliang Power Supply Company carried out a comprehensive flood hazard inspection at the 330kV Chengji Transformer Substation.

Substation operation and maintenance staff patrolled all equipment corridors of the substation, carefully checking equipment sealing and insulation performance, clearing drainage ditches in a timely manner and switching on dehumidifiers, and monitoring the moisture-proof status of terminal boxes in real time to forestall safety hazards such as rainwater backflow and equipment discharge caused by dampness.

The Transmission Inspection Center adopted an innovative three-dimensional inspection model integrating unmanned aerial vehicles (UAVs) and manual patrols. Ground inspectors wore raincoats and trekked slippery mountain forests and river beaches for offline inspections; UAVs took off through rain mist to focus on river-crossing lines, forest corridors and high-risk landslide sections. Supported by intelligent UAV hangars and visual monitoring platforms that transmit real-time on-site footage, concealed safety hazards including floating debris tangled on lines and pole foundation collapse from soil erosion can be accurately identified from a long distance.

All local power supply stations conducted full-coverage hazard inspections on 10kV distribution lines, focusing on pole foundation settlement in low-lying areas and tree obstacles along lines. A hazard ledger was established with closed-loop rectification management in place. For urban construction sections, technicians took initiative to deliver safety technical briefings on cables to avoid external damage risks. Meanwhile, special transformer users in industrial and commercial sectors were visited, with on-site guidance provided on practical moisture-proof operation and maintenance of equipment during flood season.

At present, all emergency repair teams of Pingliang Power Supply Company implement a 24-hour standby system. Sufficient emergency supplies including flood sandbags, drainage equipment and insulated repair tools are in stock, and all repair vehicles stand ready for immediate dispatch. All operation and maintenance staff track real-time changes in rainfall and water levels, and maintain round-the-clock duty to guarantee safe, stable and reliable operation of the regional power grid.