Modular and Space-Intensive Structure Solution: The Breakthrough Application of GIS Voltage Transformers in Compact Urban Substations
Challenge: Space Constraints of Traditional GIS Voltage Transformers
In urban core areas, underground substations, or high-density power distribution networks, substation space resources are extremely scarce. Traditional GIS Voltage Transformers (VTs), due to their standalone structure, suffer from large physical size (footprint area typically exceeding 4 m² for 400kV equipment), dispersed components, and complex gas compartment connection points. This not only leads to lengthy installation cycles but also makes it difficult to meet the design requirements of modern compact substations, becoming a key bottleneck restricting urban grid upgrades.
Solution: Sandwich-Style Modular Integrated Design
Integrated Functional Structure
Core Innovation: Utilizes a "VT-disconnect switch sandwich module," integrating the electromagnetic voltage transformer (VT) and the isolation/earthing switch into a single gas compartment unit.
Structural Advantage: Eliminates flange connections between traditional discrete components, reducing gas compartment interfaces and sealing points by 50%, significantly lowering gas leakage risk and potential failure points.
Example Parameter: Length of 400kV GIS VT unit compressed to ≤ 1.8m, wiring complexity reduced by 60%.
Lightweight Shell Technology
Material Upgrade: Shell adopts high-strength aluminum-magnesium alloy (tensile strength ≥350MPa), replacing traditional steel casings, achieving a 25% reduction in wall thickness under equivalent insulation strength.
Space Compression: Overall diameter reduced by 30% (e.g., 400kV VT outer diameter optimized to Φ600mm). Equipment footprint area ≤2.5 m² (including operating mechanism), adapting to ultra-narrow 2.5m×2.5m shaft layouts.
Expected Benefits: Redefining Equipment Standards for High-Density Scenarios
Indicator |
Improvement Rate |
Practical Value |
Installation Man-Hours |
Shortened 40% |
Single VT installation time from 12 → 7.2 hrs |
Space Utilization |
Increased 35% |
Saves 1/3 equipment footprint area for same substation capacity |
Applicable Scenarios |
Limits Broken |
Underground substations / Multi-level substations / Retrofitting old stations |
Lifecycle Cost |
Reduced 18% |
Lowered O&M complexity ↓ + Reduced failure rate ↓ + Reduced energy consumption ↓ |
Application Scenario Validation
This solution has been deployed in projects like the underground 275kV substation in Shinjuku, Tokyo, and the Shanghai Hongqiao Business District smart grid:
Space Adaptability: Successfully integrated 6 groups of 400kV VTs in an 18m-deep underground shaft, achieving a device density of 0.4 units/m² (traditional scheme ≤0.25 units/m²).
Reliability Record: Zero seal failures over 12 months of continuous operation, partial discharge < 3pC (meeting IEC 62271-203 standard).
Conclusion: The Inevitable Evolution of Compact Design
Through the technical path of Modular Integration (Integration) + Lightweight Materials (Lightweighting) + Structural Optimization (Compaction), this solution redefines the spatial efficiency boundaries of GIS voltage transformers. Its value lies not only in freeing up 35% of substation floor space but also in providing a scalable hardware architecture foundation for the future ultra-high-density urban power grid.
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