Overview:
Current transformer coils for GIS are used for current and electric energy measurement and relay protection in 66kV-500kV sulfur hexafluoride enclosed combination appliances.
Structure introduction:
The transformer wire circle is made of high magnetic permeability cold-rolled silicon steel sheet or microcrystalline alloy material. The secondary winding is made of polyimide enameled wire with high strength, high temperature resistance and thickened paint film. Polyester film is used as interlayer insulation, with high insulation strength.
The secondary winding is wrapped by a double-head winding machine, which can complete the winding of insulation and wires at the same time. The number of wire turns and tension program control can avoid uneven wire tension and errors in the number of turns during the manual winding process; the DC resistance of the same batch of coils has very little difference.
The insulation between wire layers is made of polyester film, with a high withstand voltage of 10kV/mm.
The windings are wrapped with high-temperature resistant polytetrafluoroethylene tape and cast with saturated cyclic chlorine resin, which has high electrical insulation strength and excellent heat resistance.
The secondary coil is cast in a metal cover using epoxy resin material. After curing, the coil and the metal cover form a solid whole, ensuring that the secondary coil will not be disturbed by friction during transportation.Rubbing or misalignment may cause insulation damage.
