What is a 35 kV SF₆ gas-insulated switchgear (GIS)?

I. Core Definition: A Milestone in Hermetic Smart Distribution

The 35kV gas-insulated switchgear (C-GIS) is a medium-voltage switchgear using SF6 gas as the primary insulating medium. It fully seals components like circuit breakers, disconnectors, and transformers within stainless steel gas tanks, achieving all-insulated and fully enclosed distribution. As an innovative replacement for traditional air-insulated switchgear, its extremely compact design (width reducible to 600mm) and environmental immunity make it ideal for urban grids, renewable plants, and extreme environments.

This independently developed SH Power product breaks foreign technology monopolies by adopting low-pressure SF6 insulation (0.04MPa working pressure), combining vacuum interruption and smart monitoring systems, showcasing China’s manufacturing prowess in power equipment.

II. Technical Highlights: Four Breakthroughs of Independent R&D

1. Gas Tank Innovation

   • 4-6mm304 stainless steelwith robotic welding ensures hermeticity (annual leakage ≤0.1%)

   • Independent pressure relief channels for fault safety

2. Eco-Insulation Technology

   • N2/SF6 mixture balances insulation and low-temperature operation (down to -30℃)

   • Dry air insulation option with GWP<1 supports carbon neutrality

3. Smart Integration System

   • Embedded sensors monitor gas pressure, temperature, and arc status in real-time

   • IoT-enabled remote control for unmanned substations

4. Modular Flexibility

   • Standard units: busbar chamber, circuit breaker chamber, cable compartment, etc.

   • Post-expansion compatibility reduces upgrade costs by 30%

III. Performance: Leapfrogging Traditional Equipment

IV. Applications: From Tibetan Plateau to Eastern Coasts

1. High-altitude grids

   • Nagqu, Tibet substation at 4,500m runs at full capacity without derating

2. Coastal corrosion resistance

   • Zhoushan Islands project withstands salt spray (IP67)

3. Urban core areas

   • Shanghai Jing’an underground substation with silent design (≤45dB)

4. Renewable integration

   • Inner Mongolia wind farm compatible with PV/wind grid connection

V. Independent R&D Journey: Three Technical Steps

1. Material breakthroughs

   • High-precision stainless steel welding with <0.1mm deformation

   • Localized epoxy insulators with dielectric strength ≥30kV/mm

2. Mechanism innovation

   • Three-position switch integrates isolation-off-grounding, 10,000+ mechanical cycles

   • Permanent magnet actuator replaces springs, operation <40ms

3. Smart enablement

   • NDIR infrared SF6 sensors detect leaks at 1ppm precision

   • Compliance with State Grid Q/GDW 11071.3-2021 standard