Advanced Electrical Insulation Testing for Grid Reliability

Modern extra-high voltage electrical grids demand total insulation integrity across substation equipment. Gas Insulated Switchgear, Gas Insulated Lines, and Hybrid Gas Insulated Switchgear require stringent diagnostic testing during factory production and site commissioning. The GTU High Voltage Non-Partial Discharge Combined Test Platform and the GIS AC Withstand Voltage and Partial Discharge Combined Test System represent an advanced engineering response to these rigorous insulation testing challenges.

This combined test setup is specifically built to evaluate the dielectric strength and localized discharge behavior of high-voltage assets. Operating directly under SF6 gas insulation or direct flange interfaces, the system replaces traditional air-insulated testing transformers, delivering superior precision in adverse factory and field environments.

Primary Operating Scenarios

The system excels across multiple critical electrical testing applications:

• Factory type testing and routine insulation validation for GIS, GIL, and HGIS gear.
• On-site AC withstand and partial discharge commissioning tests for new substations.
• Dedicated dielectric endurance testing for basin insulators and internal transformers.
• Post-overhaul maintenance inspections requiring synchronous dielectric voltage withstand and PD detection.
• Extended testing for conventional transformers, switchgear, and bushings via optional HV bushings.

Core Engineering Advantages

Compared to traditional separated test sets, this integrated system offers remarkable technical improvements:

• Ultra-Low Background Noise: Enclosed high-voltage components prevent external corona noise. Background partial discharge remains below 1 to 3 pC at rated voltage, enabling high-precision laboratory results in normal factory workshops.
• Enhanced Operational Safety: Live elements are enclosed inside a fully grounded metallic vessel, eliminating bare high-voltage risks for testing operators.
• Rapid Field Assembly: Direct flange docking with GIS eliminates long high-voltage leads and support insulators, cutting installation time by over 50 percent.
• Compact Modular Structure: Single-tank construction with modular variable frequency control consoles minimizes station footprint and simplifies transport.
• Dual Voltage-Boosting Modes: Operators can choose direct power-frequency boosting or variable-frequency series resonance modes to test large capacitive long-busbar GIS.

Technical Specifications

Frequently Asked Questions

Q1: Why is low partial discharge crucial during GIS AC withstand tests?

Microscopic defects in SF6 insulation can trigger catastrophic failure. Controlling background PD below 1-3 pC ensures early detection of minor defects before energization.

Q2: Can this platform test traditional non-GIS equipment?

Yes, equipping the system with an optional external high-voltage bushing allows testing of power transformers, insulators, and conventional switchgear.