Industry News

Stress control method of Cold Shrinkable Cable Accessories

2022-04-02
As we all know, whether a product is good or not depends to a large extent on the technology used to make the product. Product materials are good, the use of advanced technology to produce products, is very popular; Conversely, things made by backward technology, even if the quality is good, are not easy to use. There are four common stress control methods for Cold Shrinkable Cable Accessories:

1. Electrical stress control method:
The essence of electric stress control is to control the size and distribution of electric field intensity in cable accessories. Effective measures such as structural design are taken to evacuate the concentrated electric field inside the cable accessories, so as to achieve the purpose of electric field homogenization, reduce the probability of local breakdown, and improve the reliability and service life of the cable accessories.

2. Stress cone dispersion method:
The stress cone dispersion method is to reasonably epitaxial the fracture of the outer shield layer of the cable, forming a stress cone with arc shape, making its zero potential form an external horn shape, increasing the radian of the power line, so that the concentrated electric field intensity can be evacuated and electric field distribution can be improved. In terms of electrical Angle, stress cone dispersion is the safest and most reliable method. However, the insulation layer size of cable accessories is very strict, and the installation of cable joints is complicated, and lubricating oil should be introduced to avoid the formation of new tips.

3. Electric stress layer control method:
The electrostress layer control method is to introduce a composite dielectric layer (electrostress layer) with high dielectric constant into the fracture of the semi-conductive shielding layer of the cable, and adjust the electrical parameters of the dielectric in the electrostress layer to control the potential distribution of the insulating surface at the fracture of the shielding layer and improve the electric field distribution. Generally, the high dielectric constant electrical stress control material is a composite material made of polyethylene or ethylene propylene rubber as the matrix, and its dielectric constant is greater than 20.

4. Refractive stress control method:
Refraction stress control method, that is, in a setting outside the cable shielding high dielectric constant (K value is around 30) material, high elastic stress control tube, use of its dielectric constant difference and the main insulation, thus reduce shielding mouth of the electric field intensity, the high dielectric constant of the stress control tube high insulation resistance, dielectric strength is big, In the long-term effect of electric field and high temperature, the parameters can remain stable, and can effectively improve the electric field distribution on the surface of the terminal, and the terminal shape size is small, the installation space is small.

In addition, the cold shrinkage cable accessories also have a unique stress cone control unit, product structure design for the built-in stepped stress cone, stress evacuation more effective, more reliable product operation. With a coating semi-conductive shielding layer, the outer semi-conductive layer of intermediate joint products is molded by injection rubber, with corresponding thickness, so as to ensure the performance of the outer semi-conductive layer and the safety of the whole joint. The cold shrinkage bushing produced by HUAYI CABLE ACCESSORIES Co.,Ltd. uses this stress cone control unit to control the stress of Cold Shrinkage Cable Accessories.