Brand | Switchgear parts |
Model NO. | 252kV platform engineering insulation torsion bar |
Rated voltage | 252kV |
Series | RN |
The insulation torsion bar of 252kV platform engineering is a key component in 252kV gas insulated metal enclosed switchgear (GIS), mainly used to connect the isolating switch body and operating mechanism, and play a role in transmitting torque and insulation. Here are some introductions about it:
Structural features: In the 252kV vertical isolation switch, one end of the insulation torsion bar is fixed on the bearing, and the other end is connected to the transmission gear. The transmission gear meshes with the transmission rack, and the moving contact is fixed on the transmission rack. The insulation torsion bar, transmission box, and transmission shaft crank arm are installed on the same side. Through the action of the transmission shaft crank arm, the transmission box and insulation torsion bar can be driven to rotate, thereby driving the action of the moving contact to achieve the opening and closing operation of the isolation switch.
Material selection: Fiber reinforced epoxy resin based composite materials are usually used. In order to improve the wettability and interface compatibility between fibers and epoxy resin, and avoid internal defects such as gaps, the reinforcing material can be a mixed woven fabric of aramid fibers and polyester fibers, with epoxy resin as the matrix material, aramid fiber bundles used in the warp direction, and polyester fiber bundles used in the weft direction, mixed and woven into a two-dimensional fiber cloth.
Performance requirements:
Electrical performance: It is necessary to have good electrical insulation performance to withstand long-term electric field effects at a voltage level of 252kV. The axial and radial electrical insulation strength of aramid insulated pull rods used in 252kV GIS reached 15.1kV/mm and 16.5kV/mm, respectively, with a dielectric loss of 0.005%. There was no flashover or discharge breakdown after 15 cycles of power frequency withstand voltage of 460kV/5min and lightning impulse of ± 1050kV (1.2/50 µ s), and the partial discharge at 175kV voltage was 0.08pc.
Mechanical performance: Due to the mechanical stress generated by the operation of GIS isolation switches, the insulation torsion bar needs to have high mechanical strength and good fatigue resistance. For example, the compression strength, bending strength, and shear strength of aramid insulated pull rods used in 252kV GIS are 182MPa, 267MPa, and 29MPa, respectively, and the failure tensile force can reach 176kN, which can meet the requirements of engineering use.
Manufacturing process: Generally, the vacuum pressure impregnation molding process is used to wind the aramid/polyester fiber mixed woven fabric into a mold. Under the action of vacuum pressure, the woven fabric is impregnated with an epoxy resin system, and after high-temperature curing, an insulating torsion bar is produced. This process can make the internal structure of the tension bar dense, and the interface bonding between the resin and the fiber fabric is good and fully impregnated.
Note: Customization with drawings is available