State Grid Hangzhou boosts lightning protection amid peak summer demand

On Aug 12 at 7:10 am, State Grid Hangzhou Power Supply Company workers began live-line operations on the 10-kilovolt Baojia D831 line in Fuyang, Zhejiang province. Wearing heavy insulating suits from an insulated bucket truck and over 10 meters above ground, the team installed new overvoltage protection leads to reduce lightning-related faults during peak summer electricity demand. 

Fuyang's complex terrain and variable climate make the area prone to lightning strikes. When thunderstorms cause overvoltage flashovers on overhead insulated conductors, the insulation layers can break down, leading to short circuits. Electric arcs generated under these conditions can melt conductors and damage insulators before circuit breakers activate, posing risks to grid safety.

To address this problem, the company has installed newly developed ring-type overvoltage protectors. When lightning strikes occur, these devices direct the current into their main body. Using zinc oxide varistors, they release lightning energy while blocking power frequency currents, preventing conductor breakage and insulator damage. The design reduces risks associated with aging equipment, poor construction quality, and grounding failures linked to traditional surge arresters. Conditions during the operation were extreme. Workers in sealed insulating suits performed precise wiring tasks in temperatures that turned the steel tower into what felt like a furnace. Sweat soaked their uniforms and dripped from helmets onto insulated gloves, evaporating almost immediately. Despite restricted movement from the heavy gear, crews executed wire clamps and lead connections with steady precision, successfully integrating the new protectors into the grid.

Alongside equipment installation, State Grid Hangzhou Power Supply Company continues to expand lightning protection efforts. The utility is developing additional surge protection technology, increasing real-time monitoring and maintenance, and strengthening grid resilience against thunderstorm-related risks.

The company plans to further extend live-line operations and advance intelligent grid management. These measures aim to improve response times and strengthen the power supply system to ensure stable electricity for households during peak summer consumption.