Distribution Upgrade & Renovation Project of Ring Main Units for Old Urban Streets in Lucheng District, Wenzhou, Zhejiang
2026-06-09
Project Location: Distribution network of old urban streets, Lucheng District, Wenzhou City, Zhejiang Province
Commissioning Time: June 2025
Applied Equipment: 10kV fully insulated gas-insulated ring main unit (RMU)
1. Project Background
The old urban area of Lucheng, Wenzhou features dense streets, narrow roads and closely distributed buildings. The original power distribution facilities mainly consist of aging overhead lines and outdated switchgears, which suffer from low insulation performance, poor dustproof and waterproof capabilities. Common hidden dangers include frequent line tripping, equipment condensation and electric leakage. With the annual growth of power load in the old urban area, the original radial power supply structure exhibits low power supply reliability. A single line fault is likely to cause power outages in the entire block, failing to meet the reliable power demand of local residents and street merchants. Restricted by difficult land acquisition and extremely limited distribution space, large-scale civil distribution rooms cannot be constructed. It is urgent to adopt miniaturized, high-reliability and maintenance-free ring main equipment to upgrade the power grid structure.
2. Renovation Solution
The project adopts fully insulated and fully sealed gas-insulated ring main units to replace outdated switching equipment and build a 10kV ring network power supply structure for the urban area. Featuring compact size and small floor area, the equipment can be installed on street corners, green belts and narrow open spaces without constructing new distribution rooms. Multi-section ring main units are applied to realize line segmentation, connection and fault isolation, transforming the original single radial power supply into a dual-power mutual backup ring network power supply mode. Equipped with complete anti-misoperation interlock, live display and fault detection functions, the equipment supports rapid protection against short circuits and overloads, and delivers excellent moisture-proof, condensation-proof and pollution-resistant performance suitable for the complex outdoor environment of old urban areas. Supporting distribution automation terminals are deployed synchronously to realize rapid fault location, isolation and self-healing recovery of non-faulty sections.
3. Project Achievements
The ring network grid renovation realizes accurate isolation of faulty sections and uninterrupted power transfer in non-faulty areas, greatly improving regional power supply reliability. The fully insulated and sealed design eliminates equipment faults caused by outdoor humidity and pollution, reducing the equipment failure rate by more than 85%. Without the need for civil distribution rooms, it effectively saves precious land resources in the old urban area and minimizes the impact of construction on street traffic and residents’ lives. The distribution network achieves automated self-healing and greatly shortened power outage duration, ensuring continuous and reliable power supply for residential communities and street businesses. This project serves as a benchmark for refined distribution network renovation in old urban areas of southern Zhejiang.