Insulation components for generator circuit breakers

The insulation components used in generator circuit breakers are key components to ensure the safe operation of high-voltage electrical equipment, and their design must meet the insulation, mechanical, and thermal stability requirements under high voltage and high current conditions. The following is a comprehensive technical analysis:
1、 Core functions and design requirements
Electrical insulation performance
Need to withstand power frequency withstand voltage (42kV/95kV) and lightning impulse withstand voltage (75kV/185kV) at rated voltage (such as 12kV/40.5kV)
Partial discharge capacity should be ≤ 5pC, and surface electric field strength should be controlled below 15kV/mm
Mechanical strength
Need to withstand the electric force generated by short-circuit current (such as 50kA/3s), with a tensile strength of ≥ 80MPa
The deformation of supporting parts is ≤ 0.45mm, and the interface stress is below 70MPa
2、 Typical Materials and Structures
Material selection
Epoxy resin composite materials (such as alumina filling) are used for equipment below 126kV, with a dielectric strength of ≥ 30kV/mm
The 800kV equipment adopts SF6 gas composite insulation, combined with multi-layer "metal insulation metal" structure to suppress electric field distortion
Structural optimization
The pot type insulator adopts a three-phase common box design, and the theoretical water pressure failure load value needs to be ≥ 3 times the design pressure (such as 3.53MPa for 252kV products)
The insulation components at the stator end are made of nylon PA66 material with a wall thickness of 0.5mm. The modular design reduces replacement costs
3、 Manufacturing and Testing Standards
Process requirements
Vacuum casting process is used for parts below 126kV, while 800kV parts require 3D printing and gradient material composite process
X-ray inspection to detect laminated defects, ensuring no internal air gaps or impurities
Environmental Protection and Standards
Must comply with GB/T 11022-2020 "Common Technical Requirements for High Voltage Switchgear and Control Equipment Standards"
800kV equipment needs to reduce SF6 gas consumption by 15% to meet the requirements of the "Guidelines for the Demonstration of the First Batch of Key New Materials"
4、 Typical application scenarios
12kV/40.5kV circuit breaker: used in urban distribution networks and industrial power supply systems (such as automobile manufacturers)
252kV/363kV GIS equipment: used for connecting the main busbar of ultra-high voltage substations

Note: Customization with drawings is available