Top-Core Gas-Insulated Current Transformers (72.5–800kV )

Property Specification

Type: High-Voltage Top-Core Gas-Insulated Current Transformer (72.5 kV to 800 kV)

Features: Designed around a top-core housing architecture with gas insulation for heightened operational safety and reliability, this instrument transformer handles operational currents up to 4000 A across voltage classes ranging from 72.5 kV to 800 kV. Key construction highlights include a compact primary conductor path that reduces ohmic thermal losses, electrolytic copper windings, and high-permeability grain-oriented laminated steel cores. Built with structural margins against wind loading, terminal strain, and seismic activity, it incorporates integrated remote gas density monitoring with dual alarm and lockout thresholds,

Applications: Tariff and revenue metering systems, protective relaying networks for transmission grid safety, and real-time load monitoring, power flow analysis, and supervisory control systems.

Description

Key Technical Performance Specifications

Technical Parameter / Specification Specification Rating / Capability
Deployment / Environment Outdoor
Structural Architecture / Construction Free-standing Top-Core Configuration
Dielectric Insulation Medium SF6 Gas
Rated Maximum System Voltage 72.5 – 800 kV
Maximum Primary Current Capacity Up to 4000 A
Short-Circuit Withstand Capability Up to 63 kA
External Insulator Material Porcelain or Composite Silicone
Power-Frequency Withstand Voltage Rating Up to 975 kV
Annual Gas Emission / Leakage Rate < 0.1% per year
Operating Ambient Temperature Limits -50°C to +40°C (Standard)
Environmental Pollution Level Class Class IV (Very Heavy)